I totally agree. I followed Davids advice on my SBC and she just rips. Best motor i have built so far. for the most part the rotating assembly was the same. the cam was based on Davids calculations and this motor is a total ripper compared to the others..
I have auto machineshop experiance since 1960 and welding fabrication since 1972 and lots of performance experiance and while I do not know it all I do recognize it when I see it. I am amazed at the wealth of knowlege you are sharing here. Your conclusions backed up by testing and data are totaly valuable and beat the hell out of bs conversations at the sonic burger. I really appreciate what you are sharing with the rest of us. Thanks
I agree with everything that was said about duration, lift & LSA. Valve events should not be considered a mysterious gray area meant for mathematicians or quantum physicists. At the very least, anyone looking for a cam should know how much overlap they're getting and when the intake valve closes which is the most important event by far. Overlap is responsible for the thump thump and for scavenging which helps overall efficiency. When the intake valve closes has a lot to do with what RPM range the cam will be happy and more importantly, it has a drastic effect on compression.
Bingo. Intake valve closing events being wrong can ruin a motor with the resulting detonation requiring to back the timing way off or retarding the heck out of the cam. Totally changes the plan.
I wish I would’ve ran across this video before sounding like a complete noob and asking ignorant questions in the live LoL regardless, I left smarter than I came and have a much better understanding of how cam specs are made up of, thanks Richard!
Sorry I didn’t watch live. I also apologize for a long post. I’m going to try to explain how to compare cams more effectively than just intake duration and LSA. Stop now if you don’t care. Maybe I’m a cam nerd or something, but a couple calculations get you beyond intake duration and LSA to describe a cam. The first takes one simple formula, the second takes two. The most significant parameter is to convert duration and LSA to intake closing (IC). You need intake centerline, determined by LSA and cam advance, and intake duration to determine IC. Many cams are installed at 4° advanced, and I use that number unless the advance is stated. If the specs say LSA 113 +3.5, that means the cam is ground with 3.5° advance, so you’d use that instead of 4°. The calculation is duration divided by 2 plus intake centerline. Example: the Comp 459 cam. 231/2 +109=224.5, subtract 180 and you have 44.5° ABDC for IC (intake closing). That number gets you a power peak around 6500-6800 rpm for a 6.0 or 6.2 LS, 7000 or more for a 4.8. The variables are head flow, intake runner length, and displacement which also affect those numbers. To get a power peak rpm like that with a SBC, you’d need at least 10° more intake closing, most likely. A BBC with a long stroke (496, 540, etc) will take another 10° or more to make power at rpm because of displacement, bore size, intake valve size, etc. The other factor, which takes two calculations, is overlap. We figured intake centerline from LSA above by subtracting cam advance. Exhaust centerline is LSA plus cam advance. LSA is physically ground into the cam. Every degree that you adjust the cam in the advance direction reduces the intake centerline and increases the exhaust centerline. We need the intake and exhaust duration numbers, LSA, and advance to calculate overlap. Intake opening (IO) is duration divided by 2 minus intake centerline. Exhaust closing is exhaust duration divided by 2 minus exhaust centerline. Using the 459 cam at 4° advance again we get 231/2-109=6.5° ATDC and 239/2-117=2.5° BTDC. Positive numbers are more overlap, negative numbers less. Here we have 9° of overlap, meaning the intake and exhaust valves are over 0.050” for 9° around top dead center. Overlap generally improves mid-range torque, which in turn improves power. Like on the intake closing, displacement, bore size, intake valve size, and head flow all affect the engine’s need for overlap. Bigger engines and long stroke small bore engines want lots more overlap than smaller or short stroke big bore (over square) engines. For a particular engine family you can compare two cams by converting intake duration, LSA, and cam advance to IC or intake closing after bottom dead center (ABDC). Comparing two cams IC number gives a very good indication of relative top end performance. Increase at the top is almost always decrease at the bottom, other things being equal. Again, a particular engine will have more mid range power (fatter torque curve) with more overlap. Small engines need less than big engines and idle quality, or idle chop sound, increases with overlap. You can definitely have too much overlap, but too little steals mid range. Just compare an LS9 factory cam curve to an aftermarket cam. The wide LSA steals overlap and kills mid range compared to the aftermarket cam. I hope this helps someone out there. Maybe all it does is validate why Richard just uses intake duration and LSA.
I asked Ashley at comp cams long ago, why do your shelf cams have to wide of a lobe separation or not enough overlap. He said we have to save people who will use too much dur from themselves and of course blaming the cam co. When the engine doesn't do what it should, or what they expect
@@davidreed6070 I’m not familiar with people retarding turbo cams. In general, retarding the cam puts IC later, which should move the power band up. In practice, at least as I see it on Richards dyno graphs, very little increase shows up. For a few degrees in the other direction, torque does improve. But you can quickly go to far. Brian Tooley says you should just put the valve events where you need them to be. With a longer exhaust lobe, that means advancing the intake lobe to keep the overlap centered, more or less, at TDC. I should warn you that this info is from looking at/reading a lot of other people’s work. I don’t have a dyno...
I'm doing research "how cams effect performance" even tho I'm running a bmw with two cams + vanos. (Yes i understand my Lsa is variable to some degree ) This comment has more gems and good info than a who day searching Google. Thankyou. I'm still looking for more information about reverse split cams/ high exhaust manifold pressure. Even n.a. bmw cars seem to run a "reverse split" from factory(24 valve m50/m52/m54 ect.. cars )
True story: I studied physics in my first year of undergrad. We learned calculus and differentials in physics before we learned about them in the math classes. The physics prof explained to us at the beginning of class that to learn physics, we'd need the math and he also knew that the math classes were pure and not applied, so they dwelled on theory at the expense of speed. The physics prof showed us the practical uses of the math that we'd learn more rigorously later. It was odd in the moment, but it made the mathematics classes way easier to understand for all the people taking physics.
I took physics last and I quickly realized it's basically math, just in motion. Thermalfluid dynamics was the one that broke my brain! Hardest class I've ever taken lol it was like physics but only dealing with fluids which just further complicated everything by adding viscosity and the like into the physics
If it were really that simple, the engineers who design cams wouldn't have jobs. There are a lot of forces at play on various components and many people completely forget to think about the tribology or material strength.
@@stephendee7839 That's understandable, but at the end of the day, you end up with a 7500 RPM engine that has a long soft spot along the middle of the curve, where you could have had a 6500 RPM engine that hits harder, all the time, with less valvetrain stress.
@@stephendee7839 Would you mind elaborating there? I don't blame you for coming to that conclusion. -- Where I'm from, people tend to buy stuff and slap it together. So, a given cam/valve/pushrod package might be stable enough to not drop a valve, since it's a validated kit. They fail to realize though, that they get a long duration cam on a stock intake that pushes the practical operating range beyond where the intake resonates. That's a simple computation of percentages, grade-school mathematics. That, is what I frown on.
Built in 1981- 340, X-heads shaved 60 thou, port matched, mild porting and polish, Holley Street Dominator, 800 Thermoquad, 302dur. .468 lift solid lifter 104 degrees overlap and Hooker competition headers, balanced bottom end, for my 69 GTS Dart, line lock, 4:10 Richmond gears in an 8 3/4 with an A833 shifted by a Hurst Ram Rod shifter, and line lock, this was my toy for the streets back then. Was guesstimating around 425hp as dyno's were very rare here in Canada back then.
Thank you Richard for the video. I agree with the assessment of most people don't understand calculas before Trigonometry. But!!, a good teacher can explain valve events in a way that someone could understand in relation to why the event is happening. I appreciate your videos very much. Thank you
When I was in high school everyone just claimed they were running a Three Quarters RACE cam! Everyone would nod their heads and go that's pretty extreme man! Pretending that we knew what they were talking about
Yeah, that one was popular where I grew up. Never knew what that meant. 3/4 of what? Only has lobes for 6 cylinders? I suppose it was some duration number 3/4 of the way between a stock SBC grind and the Duntov 30-30. (Whatever a 30-30 cam is. Never knew that either.)
@@andyharman3022 from what I was taught back in the 60s and 70s you could order a full race cam from the factory dealership or a smaller three quarter race cam depending on what type of street drivability you wanted.
@@andyharman3022 3/4 vs full race, that came about when there werent many cam grinds. The term 30-30 is a reference to the solid-lifter cam's valve lash settings assigned by Chevrolet.
Richard, I'm by no means a pro when it comes to camshafts, however, I do know enough to get me in trouble from time to time. So... I'm putting a simple, but stout pump gas 10.2 to 1 (should be around 8.4 dynamic), great flowing aluminum AFR heads, 350 SB Chevy together with an old grind hydraulic roller camshaft from Comp Cams (known as the "306" grind). The cam specs are "roughly" 230/ 244 at .050" (Actual according to cam card is 229/ 245 degrees) for duration and a lobe lift of .340/ .361 ( .510/ .540 with a 1.5 rocker) with a wide LS of 112 degrees advanced 4 degrees from Comp to 108 degrees). Also, for you to know is that I'll be using ported and cnc"ed Corvette rams horn manifolds with a very high flowing 2 1/2" exhaust. After explaining all of that, my question is this: If I run a 1.6 ratio rocker on the intake side and a 1.5 ratio rocker on the exhaust, I'll have a .544/ .540 lift with the supplied cam lobes from Comp. With the 229/ 245 split in duration, shouldn't that combo of lift work just fine with that duration and a smaller exhaust? Also, would increasing the lift to .544" with a short 229 degree duration still be easy on the valve train for street usage? Any help or thoughts would be appreciated. Thanks in advance, Jim Howard
One valve event that is very important to know is when the intake valve closes. Once you know that you can use a dynamic compression ratio calculator on the internet to determine what static compression ratio will give you the best performance depending on fuel octane.
Cams are a great way to make power just remember there is a give and take . You will give up low in power for high in power on most stockist engine. Just remember don't give up too much squeeze with a large intake duration because you give up too much low end power.
Richard, part of learning is learning who to listen to, who knows what they're talking about and who was full of b*******. But you have the truth backed up by the Dino and that's very helpful. Thank you very much for speaking the truth
Its all about the combo, and you can run a LSA of 108- 110 which is considered tight with Nitrous and make great power. Some blower companys like 110 LSA to make power over 114 , plus helps with cooling the exhaust valve. Engine masters did a comparsing between a normal 110 LSA cam and a spec blower cam for a supercharger setup and the difference was minimal..seat of pants wouldnt tell the difference. Its all a selling marketing bit. Richard is correct for the most part. As Richard says this is the basics. There is more too it . cubic inch , bore , stroke, head flow, valve dia., compression. I learned alot from Dave Vizard, Bill Grumpy Jenkins, Warren johnson and Mike Jones . LSA is not the most important number , its just a fraction of the big picture. Plus LSA only changes the power range by 500 RPMs up or down. MHO...🤔
I know this for fact....Chris Straub spec’ed a HR cam for my 454....it rips, big torque. I stumbled across Dave Vizards cam calculation and crunched the numbers for my engine....Vizards numbers matched the cam that Straub spec’ed for my BBC..... Coincidence? 109 LSA engine loves it....
@@richardholdener1727 What’s the mathematical equation to determine each valve event? It’s physics, fluid flow and pressure waves moving at the speed of sound adjusted for temperature. There has to be some associated math whether pure theory or empirical because some folks use some sort of model to spec cams. It seems proprietary, but surely some mechanical or civil engineering professor has derived something that has been made public. Are you aware of anything considering your large network? You do a great job with all your testing and sharing of information! Thanks!
Vavle events is how i picked the cam for my twin GT3582 4.8L. The "normie" cam specs are 200/216 .580" 114 +4. Would i have ever picked this cam based on those #s? HELLL NO. It even has -10° of overlap. Does it work? HELL YEA, better than could have ever hoped and it idles like stock. Traps at 142mph in a 4000lb car at 27psi of boost. Best part is the drivability.
I'm seriously going to buy the Truck Norris cam kit. Just so I can tell people, "I have the Truck Norris kit in my Sierra!" 😂 Obviously, I'll replace or upgrade a few other parts while I'm in there, but this *_will_* happen in the very near future!
Take a stock lt1 5.7l the cam is ( lift) intake .447/.459 exhaust and int .205/ .207 exhaust (duration) .05 . If you divide 205 stock intake by 300"hp" by 205 int cam you get = .68 as a ruff value of what represents in this eng sbc meaning the numbers on the cam to achieve 100hp. You can take the 300hp divide x 205 = 1.46. (example 268 intake duration cam times that 1.46 = ruffly about 391hp cam efficiency base without your other power adders like heads/ intake/ exhaust/ fuel or piston compression could be more then 100hp on top) to put ppl in the ball park provided you have the matting components easy recipe. The way I guess the right cam for the job is all the numbers matter, first the {HIGH LIFT adds AIR good for short max compression} HIGH EXHAUST moves AIR OUT, faster rev and piston, DURATION How LONG STAYS OPEN FOR FUEL/AIR SIDE TO SIDE LOB, LSA LOWER the number the more. RUFF adding to the drive ability and timing to add more fuel between and also poor gas mileage. Meaning a cam with a 268 intal duration and thought good exhaust lob as well should build you a race engine that will put you over 400hp likely and under 500hp crank unless you really spend and this is a presumed 4 bolt main.
Otto cycle is 720° of rotation. 4 Strokes-5 Events Intake, Compression, Ignition, Power, Exhaust. Ignition starts a few degrees of crank rotation before TDC on the compression stroke and completes so many degrees after TDC on the powerstroke. Cams only rotate at half the speed of a crank, timing is necessary Overlap is when both valves are open during exhaust/intake stroke for scavenging and cooling of the cylinder and head. The theoretical ideal charge which is called the stochiometric value is 15:1 however it causes engine temps to be too high so for optimal cooling is 12:1. Using the wrong cam can cause valve overlap to be reduced meaning valves open too late and close too early so cooling/air intake and heat/exhaust are not fully realized in the cylinder. Too much cylinder heat can cause preignition and detonation. Lift is only how far the valve is off its seat. Duration is how long the Valves are off their seats.
I'm used to cams we used in dirt track engines with 106 and 108 LSA. I noticed that everything you use is 110 to about 114. My cam is 107 LSA but it's still only about 500 lift. The duration is about 235/249 at .050. I know the idle will be rough but will it do well for power with a 5 speed in a very light car. It's a 360" SBC with flat tops, 0 decked and Dart Iron Eagles, 64cc. And the intake c/l is at 102° it will be run with a dual plane air gap and a 750 Holley.
For the reverse cam you might do 224/220 (218?) and step up to 224/232 or something of that kind. I guess you would keep the LSA constant for it to be a equal comparison?
@@richardholdener1727 Richard. I agree but in most cases of race situations you want max lift to be as close to max head flow as possible . can we all afford to do this hell no but what I have been taught is for example your head CFM maxs out @ .650lift@ 300CFM. For maximum power you want cam lift as close as possible to use as much CFM as possible. On the other hand using the same head but the cam lift max out at .580 and your trying to run max RPM to achieve max power a better flowing head will help were the cam falls off .
right off the bat, lift is a huge deal. you can over lift or under lift your camshaft. Flow testing the cylinder head will determine where the lift needs to be. if the lift is too small, you will starve the cylinder, if it is too much, you will lose your flow charge, and acctually decrease performance
I'd like you to talk about valve events and what effect that has - intake exhaust open and closing and also ramp rates fast open slow close and how long does it stay on the nose etc and rocker ratio changes like from 1.73 to 1.8
It's magic it what you try works :) guess it's about optimising what you have, like trying to match the cam to heads you have. Maybe your heads are a little to big for the combo you have so by changing open and close points might see some gains, same if they're not big enough or flow poorly in the low or high lift - what changes can you make to improve what you have ? You're not trying to find a 100hp every time just improve what you already have cheers I'd like a rocker ratio changes that would be interesting
I forgot to ask while live.... I had mentioned the LS9 cam, but forgot to mention that it would be in a 5.7L punched out 5.3/4.8 and ported LSA Blower. Since upgrading valvetrain anyways, would 1.8:1 rockers be a worthwhile application ? Not to band-aid a bad cam choice, but since rockers are a viable upgrade anyway. The bottom end being soft will help power management on bad launch/no prep surfaces, while leaving everything for the top end and still a tame street vehicle if/when needed.
I have a 07 suburban Iam putting a 6.2 truck motor in it like to get the best low in tq out of it to pull a boat it has 456 gears but the tires are 33 inch tall it tacks around 2500 on the inter state
I have a 86 f150 xlt lariat stock block .060 over dome pistons stroked to 352 cid with edelbrock heads roller rockers long tube headers and an 850 DP and a edelbrock intake and a lunati cam i will get a list of part numbers for you and see what you think as far as power output with VP110, and E85
Hello Richard, my name is Percy i’m running a 496 bbc with aluminum rhs 119cc, 320cc heads also have srp high compression dome pistons 12.5:1 compression but that compression is with 118cc heads and I’ve got 119cc and my cam is a 299th big muthar thumper hydraulic roller cam kit by comp cam and a rpm intake plus 850 double pumper. Cam card show duration @ .050 int 243 ex 257 lobe lift int .3350 ex .3260 lobe separation 107.0 rpm 2300 to6100
Richard, would you recommend a normal split pattern cam over a single pattern cam on a turbo LS? Grand National's cam run a lot of single pattern cam and run in the 10's.
Richard, I have an unusual motor, a 99 ram 2500 v10. I recently had a cam reground by crower because there were no available new cores. We were able to get 216 at .050" and .478"(single pattern) on a 1.7 ratio with a 110lsa. I also did my first port/polish (more polish) on the factory heads and had 2.02 intake valves installed (factory 1.92). The upper and lower intakes were both polished with the throttle body opening cnc'd to go from a twin 47mm to a single 56x108mm with custom matching throttle body. I was wondering what you think on this combo. The truck is lifted with stock 1400ish stall and all it is used for is occasional towing and off roading so torque was the primary concern all across the power band, it seemed to fall off at 4000rpm and factory shift point/redline was 4500rpm, this is documented in every dyno of one I could find as well.
ive ran a few cam's in my ls1 from stock 99 camaro, 04 ls6 cam, currently a comp 283r, but i really miss my gm hot cam it was only a 525 lift with a 112 lsa sounded amazing drove great with my 6 speed and it even passed ca smog
Would you say that, in general, a motor with limited head flow as the bottleneck (like, say, a 3800) benefits more from a cam with narrow LSA? That has always been the thinking in the Buick turbo 6 crowd, and many of the cams reflect that, with small duration numbers and narrow lobe separation angle. I've seen it work on my Dad's Buick 430, which runs better than a low compression n/a motor with headers and dual plane has any right to. The odd thing is, it seems like all of the 3800 cams available are generally 113LSA or wider. I'm wondering if it would be beneficial to have a custom grind done on a 110 center to maximize the area under the curve. I'm not after peak horsepower as much as I would like to see strong torque, quick spool, and good drive-ability, while making reasonably good power without revving it out much past 6000 rpm. I'm trying to have the best of all worlds.
Love this, always talking about my buddies about optimizing a new cam on my sbf 383w street motor, thinking about raising static compression 2points to 12.5:1. Running 248/256 at .050 108lsa .720/.688 lift kaase p38 heads. My Erson cam card has the cam timing events but would like to tweak. Running a 210 cranking pressure. Trying to pick up another 50-75 hp. All N/A power
The generally accepted rule for adding compression is that one full point of compression can add between 3 to 4 percent power. So 2 pts would be at best 8% increase in power.
All this is great. Comment you have to Match cam to head makes sense. However with not experience where is this calculations located at. I have a 383 280 cfm heads .590 left after 1.6 rockers. 227/233 .560 cam Where do I go to see how much I’m leaving on the table do to cam? !!!!
bigger cams make more peak power but sacrifice low speed power-its not how much, its where you want the power to be. Your heads can support 560+ hp, but that 227 won't make that.
@@richardholdener1727 thank you for the reply. It would be cool if head companies did testing and said. This cam made this hp/tq with our “” head. So a person can make a comparison of say 5 cams.
@@richardholdener1727 I love your channel I wish I watched it before my build. I now know why they say never purchase a cam first!!!!! Pick the cam last!!
can you give me the reader's digest version of what they mean when they list a 110+3 vs just a 110 lsa? and what does that do to the power production in rpm range, area under the curve, peak power or torque etc?
Back in the day people use to advance the cam (in relation to crankshaft) to get more torque at a lower RPM or retard the cam to move torque higher in the curve. Nowadays people are fancy and make the cam with the advance made in to it. So when you install it dot to dot its already advanced, etc.
@@baby-sharkgto4902 thank you. i can relate to that now. we raced a 2.3 ford (dirt track) and advanced and retarded the cam for track conditions. they just grind it into the cam now.
I'm really curious to see how the smaller, median and larger size cams compare down low (3-4k rpm) when they are each run with the appropriate or equal dynamic compression. I believe dynamic compression is key to a well performing street engine and has been helpful for setting up for pump gas na applications with 11to 1 static comp. Seems like the bigger cams are being shorted by not having the same cylinder pressures down low when tested on the same static comp.
I agree. I've gotten to the point where I don't really spec a cam by duration and LSA, but by certain events. The intake closing point needs to match your static compression ratio, engine geometry, and fuel type. This point determines dynamic compression. Overlap is determined by exhaust closing/intake opening and is determined by intake reflected waves, application, head flow, and a host of other specifics. This is what leads you, indirectly, to duration and LSA.
@@tadwiltman4875 Yeah your right as there is more duration you move the sweet spot in sacrifice tq on rpm, but the idea is to get the max air and fuel in the cylinder and get it out as fast ass possible. So for me I'm thinking we start with a base power we want for our build with the cam out put to be about 100hp lower then then overall end game with no power adders, find a cam with the drive ability you want and the sound your looking for ( like in If I did my exhaust on a music car would be different but for my vet bit o sleeper I need a cam that is 114 LSA or higher to be under cover and take the ol lady out. Most of thees guys are trying so hard to impress everyone with big numbers, but I like reliability best modest cam for a street beast and crazy for the guys on the track. You can get so much more out of full exhaust, valve lift, gears, stall and tires then ppl think. Caming is for big boys lol. exhaust 60hp 6 tenths , valve lift 1.6 15-22hp 2 tenths, 220gears to 373 gears 4-5 tenths , 1900/ 2800 stall converter 4-5 tenths, and good tires 3 tenths = like a 200hp conversion and 2 sec off 1/4 mile times.
Never could understand why a person wants a PD blower and then wants to put a cam that reduces the power where such a blower shines. Then they will also do a stroker motor to increase torque. How does this make any sense????? Use factory displacement with a camshaft with tighter LSA which would increase torque and horsepower for a cheaper price than a stroker kit. Remember to try and stay intellectually consistent. I know it hard for us gearheads to do. I have a Hellcat and want to cam it. I will most likely use the Tomahawk 2.0 with 111 LSA . I'd rather have 108 but 111 is about as tight as they make for the Gen 3. I'd like 600+ lift and 108lsa with duration in the 220's.
Any chance you could compare Comp Cam NSR Drift 233/243 54-777-11 on 5.3L, 6.0L, and 7.0L? A couple of us on the ls1tech forum are curious how the low lift but long duration would affect the hp/tq curves compared to stock and other cams. Would the 114 LSA be helpful under boost applications?
Hi Richard I regularly watch your you tube channel and particularly like you LS content I am building an ls and wouldn’t mind your thoughts on it In short Ls2 block 4” bore 4.125 crank Forge Piston 6cc dome Pro Comp ls7 heads (have checked flow 360@600 370@700) Comp cam 256/279@50 660 lift Short travel lifters Factory rockers (CHE trunions) all clearance are good a little shrouding around the valves because the bore isn’t really big enough Comp ratio about 12.5 -13 want to run pump fuel/e85 At this point will run factory ls7 manifold 90mm throttle body (will change if needed later on) Would like to see 600+ at the wheels Your thoughts is 600+ possible Comp ratio Cheers Rob
I'm trying to figure out a off the shelf cam for my 4V Cleveland it's going in a kind of heavy car but it will have low gears and about a 3000 stall converter
I need help Rich, ive been watching mr vizard. I have a 91 mustang gt. Im looking to do a top end kit and get a cam w specs he would figure. Is there an off the shelf cam in regards to this? I want to keep bottom end stock. Id also like to add boost later on down the line. A na cam and boost cam recommendation would be awesome. Im also keeping it efi no carb. Any help along w recommendations are highly appreciated. Another thing whats the best intakes for these? Is it holley, trickflow, or? Thanks in advance and i now know the lsa/lca is very critical. Another question, when you set ring gap for boost what do you set it to? Is there a top end kit youd recommend?
@@richardholdener1727 out of your testing which intake performed the best? ie the best intake for hp and tq. ive heard the Holley Systemax is the better of all of them. what should one gap their rings at for boost? i simply don't know is all. i just figured you go by how he selects cams as well. i'll def go to him in that regard then. thanks again
@@Dr_Reason excessive overlap can act as a boost leak. Turbo cars will still make their target boost either way if they are within their flow limits since shaft speed isn't fixed like a supercharger. PD blowers will often show less boost with more overlap, but it usually works just fine.
The thing that keeps me confused is what LSA does to the torque curve and more importantly to me is vacuum production. My Car needs a good amount of vacuum to operate the A/C controls and the power brakes want more than I have now. I understand that a wider LSA helps vacuum but hurts low speed power. meaning for my beast that needs vacuum a number like 114 LSA would be preferable over a 108 LSA. Trouble is, I like low speed power .
Richard not a cam question but id like to see your take on this .hey everyone first off Merry Christmas to all . i have a question im setting up my exhaust for running twin turbos and i bought the sniper efi system first off do i need to have two o2 sensors ? and second of all whats recommended location of the o2 sensors before the turbo or after on the outlet side of the turbos ? im almost thinking the outlet side of the turbos because its the very last the hot gases run through for a more accurate reading to the controller . any ideas or thoughts are appreciated thank you Bill
Awesome Content Brother, Looking at BTR 219 / 239 .553/553 @ 115+2 in a LS3 416 Stroker @ 11:1 CR / 823 Heads, L94 Truck intake, LS7 Crank, Manifold, Cats, 3" exhuast, to Z06 Npp 6L80 TuTd w Stockish TQ adapted to Heavy /Lite tow 80's Land Cruiser AWD Looking for Low End Torque to Mid Range w Throttle response thru Curve in a DD Seems to be a "Goldilocks" fit, might also appreciate the Sound of that large Dur Split (20) on a 115 w a -1.00 Overlap
Is The cam base circle critical on cam selection? Do the small base circle cams flex more under high spring loads or is there a preferred steel to use for small base circle cams?
W/the large base circle cams like w/the LS platforms, 55,60,&70 mm base circle cams on the BBC’s Do they tend do have more ramping flexibility as opposed to small base circle cam being harder on lifters and valve trains in general? Or does it even matter?
Building A 496 1401 compression road extra bvx3 heads I don't know what I want to use for an intake either a tunnel ram stack injection or an elderly injection I have two camshafts to choose from 1775 intake 748 exhaust duration is 286 and 295 at 50,000 would 110 lb separation or I can go to the same camshaft with 284 duration and 292 at 112 lobe separation any comments on what to do
Valve events only mean something to me when I'm tuning a car to get the injection timing right. Mainly so it doesn't stink so bad (common complaint when a cam is upgraded) and for the HP/TQ bump.
Richard, can you answer this for me? If I have 2 cams everything the same but one is .550 lift and one is .600 lift or more, how will the curve change? I like my trucks power curve exactly how it is but just want to intensify it a little bit, all the way through or at least on top end. I have some to spare on low rpm. So will lift get me what I want? Or do I need to add just a few degrees, or add one or two degrees to the LSA? Truck has ported heads and intake/tb so should be able to take advantage of any cam changes
@@richardholdener1727 it is btr stage 4 v2 .. 224/230 .558 .558 109LSA I'm thinking of going custom with 226/232 .610 .610 109 I have the ported heads, do you think I need to increase those numbers anywhere or have an offset with the lift (example .600 lift intake .630 lift exhaust) or if you think I need a bigger split on the duration or tighten it up some let me know
@@richardholdener1727 I found 2 videos from TSP comparing the same cam, one with .550 and one with .600 and the higher lift cam made like 10 more hp and tq everywhere without any loss or dip so it seems like increasing lift generally gives an even bump across the board, similar to what higher compression does
Hey Richard I'm interested in the lunati high lift voodoo 625 625 112 219 223 ging in ported 243s 6 speed car runs 12.40s with the stock ls1 cam what kinda gain should you get with ls6 intake please let me no
@@richardholdener1727 hey Richard what do you think of the lunati high lift voodoo 625 625 219 223 on 112 for full weight 6 speed ls1 with ls6 intake for all around street strip ? I mostly just take it to the track on weekends and the odd cruise just looks like that cam would give me the most average power
Sure, your turbo motors work with the cams you use, but n/a engines with anything over 108 lsa only make top end hp & zero torque. Thats just fine if you've got a track car with a 5500 torque converter and up. If you can't get traction from your suspension, I get it, but don't be telling everyone that just because your set-up makes max hp, that it has the most potencial on the track. No torque and you don't win races!
na engines with anything over 108 lsa only make top end? You need to test more or look at the many, many, many cams tested here to see where they make power
Depends on what you consider tight lobe separation cams. Back in the 80's-90's and even 2000's nitrous cams were grinded on a 108 to 110 LSA and worked great. He'll I think BDS or TBS blower companys prefer 110 LSA still due to one reason the cooling of the exhaust valve. Prostock engines use a wider LSA because of the higher duration of the cams. Just MHO and grumpy jenkins and Warren Johnson theorys.
Who cares about testing at 2000 rpm? It ain't like anyone is using full throttle at 2000 rpm. Most run a 3000 stall so why does it really matter and who REALLY cares?
@@rhubarbpie2027 IMO if you're building a PERFORMANCE engine, it doesn't matter. Especially if you're running a 3000 stall converter. If youre building a towing or low speed engine then the cam should be sized for lower rpm. Like the truck cams. I tuned a Denali and the owner/builder selected a stage 4 truck cam. Runs GREAT at 3000 rpm and up. But he was on a stock stall. I told him I would've run a stage 2 at the most. Now he is getting a 2800 stall and the trans rebuilt. Once that's done, it will get out the hole a lot better.
@@jaydubb71 maybe intensive engine modification isn't advisable for all end user applications, but regardless there are people who want different/improved engine performance and that does sometimes warrant an aftermarket camshaft.
You need to go back and figure out what LSA actually does. You are wrong in the importance. LSA should be the first thing you figure out with trying to fit a cam.
I'm a big fan for David Vizards cam calculations! His theories about needing to know your heads when deciding a cam make alot of sense too.
I totally agree. I followed Davids advice on my SBC and she just rips. Best motor i have built so far. for the most part the rotating assembly was the same. the cam was based on Davids calculations and this motor is a total ripper compared to the others..
I have auto machineshop experiance since 1960 and welding fabrication since 1972 and lots of performance experiance and while I do not know it all I do recognize it when I see it. I am amazed at the wealth of knowlege you are sharing here. Your conclusions backed up by testing and data are totaly valuable and beat the hell out of bs conversations at the sonic burger. I really appreciate what you are sharing with the rest of us. Thanks
I agree with everything that was said about duration, lift & LSA. Valve events should not be considered a mysterious gray area meant for mathematicians or quantum physicists. At the very least, anyone looking for a cam should know how much overlap they're getting and when the intake valve closes which is the most important event by far. Overlap is responsible for the thump thump and for scavenging which helps overall efficiency. When the intake valve closes has a lot to do with what RPM range the cam will be happy and more importantly, it has a drastic effect on compression.
Bingo. Intake valve closing events being wrong can ruin a motor with the resulting detonation requiring to back the timing way off or retarding the heck out of the cam. Totally changes the plan.
I wish I would’ve ran across this video before sounding like a complete noob and asking ignorant questions in the live LoL regardless, I left smarter than I came and have a much better understanding of how cam specs are made up of, thanks Richard!
Sorry I didn’t watch live. I also apologize for a long post. I’m going to try to explain how to compare cams more effectively than just intake duration and LSA. Stop now if you don’t care.
Maybe I’m a cam nerd or something, but a couple calculations get you beyond intake duration and LSA to describe a cam. The first takes one simple formula, the second takes two. The most significant parameter is to convert duration and LSA to intake closing (IC). You need intake centerline, determined by LSA and cam advance, and intake duration to determine IC. Many cams are installed at 4° advanced, and I use that number unless the advance is stated. If the specs say LSA 113 +3.5, that means the cam is ground with 3.5° advance, so you’d use that instead of 4°. The calculation is duration divided by 2 plus intake centerline. Example: the Comp 459 cam. 231/2 +109=224.5, subtract 180 and you have 44.5° ABDC for IC (intake closing). That number gets you a power peak around 6500-6800 rpm for a 6.0 or 6.2 LS, 7000 or more for a 4.8. The variables are head flow, intake runner length, and displacement which also affect those numbers. To get a power peak rpm like that with a SBC, you’d need at least 10° more intake closing, most likely. A BBC with a long stroke (496, 540, etc) will take another 10° or more to make power at rpm because of displacement, bore size, intake valve size, etc.
The other factor, which takes two calculations, is overlap. We figured intake centerline from LSA above by subtracting cam advance. Exhaust centerline is LSA plus cam advance. LSA is physically ground into the cam. Every degree that you adjust the cam in the advance direction reduces the intake centerline and increases the exhaust centerline. We need the intake and exhaust duration numbers, LSA, and advance to calculate overlap. Intake opening (IO) is duration divided by 2 minus intake centerline. Exhaust closing is exhaust duration divided by 2 minus exhaust centerline. Using the 459 cam at 4° advance again we get 231/2-109=6.5° ATDC and 239/2-117=2.5° BTDC. Positive numbers are more overlap, negative numbers less. Here we have 9° of overlap, meaning the intake and exhaust valves are over 0.050” for 9° around top dead center.
Overlap generally improves mid-range torque, which in turn improves power. Like on the intake closing, displacement, bore size, intake valve size, and head flow all affect the engine’s need for overlap. Bigger engines and long stroke small bore engines want lots more overlap than smaller or short stroke big bore (over square) engines.
For a particular engine family you can compare two cams by converting intake duration, LSA, and cam advance to IC or intake closing after bottom dead center (ABDC). Comparing two cams IC number gives a very good indication of relative top end performance. Increase at the top is almost always decrease at the bottom, other things being equal.
Again, a particular engine will have more mid range power (fatter torque curve) with more overlap. Small engines need less than big engines and idle quality, or idle chop sound, increases with overlap. You can definitely have too much overlap, but too little steals mid range. Just compare an LS9 factory cam curve to an aftermarket cam. The wide LSA steals overlap and kills mid range compared to the aftermarket cam.
I hope this helps someone out there. Maybe all it does is validate why Richard just uses intake duration and LSA.
I asked Ashley at comp cams long ago, why do your shelf cams have to wide of a lobe separation or not enough overlap. He said we have to save people who will use too much dur from themselves and of course blaming the cam co. When the engine doesn't do what it should, or what they expect
This is what I needed. One question why do I see so many people retarding turbo cams, I haven't been able to wrap my head around that.
@@davidreed6070 I’m not familiar with people retarding turbo cams. In general, retarding the cam puts IC later, which should move the power band up. In practice, at least as I see it on Richards dyno graphs, very little increase shows up. For a few degrees in the other direction, torque does improve. But you can quickly go to far. Brian Tooley says you should just put the valve events where you need them to be. With a longer exhaust lobe, that means advancing the intake lobe to keep the overlap centered, more or less, at TDC. I should warn you that this info is from looking at/reading a lot of other people’s work. I don’t have a dyno...
I'm doing research "how cams effect performance" even tho I'm running a bmw with two cams + vanos. (Yes i understand my Lsa is variable to some degree ) This comment has more gems and good info than a who day searching Google. Thankyou. I'm still looking for more information about reverse split cams/ high exhaust manifold pressure. Even n.a. bmw cars seem to run a "reverse split" from factory(24 valve m50/m52/m54 ect.. cars )
True story: I studied physics in my first year of undergrad. We learned calculus and differentials in physics before we learned about them in the math classes. The physics prof explained to us at the beginning of class that to learn physics, we'd need the math and he also knew that the math classes were pure and not applied, so they dwelled on theory at the expense of speed. The physics prof showed us the practical uses of the math that we'd learn more rigorously later. It was odd in the moment, but it made the mathematics classes way easier to understand for all the people taking physics.
I took physics last and I quickly realized it's basically math, just in motion. Thermalfluid dynamics was the one that broke my brain! Hardest class I've ever taken lol it was like physics but only dealing with fluids which just further complicated everything by adding viscosity and the like into the physics
@@swappedoutZ71 just be thankful that you didn't take a class in quantum physics.
What the DIY home-brewed performance crowd needed for decades ^ . This is gold .
People really do have to learn the math for valve events. It's simple percentages. If you really love something, you put the time into it.
If it were really that simple, the engineers who design cams wouldn't have jobs. There are a lot of forces at play on various components and many people completely forget to think about the tribology or material strength.
instaBlaster...
@@stephendee7839 That's understandable, but at the end of the day, you end up with a 7500 RPM engine that has a long soft spot along the middle of the curve, where you could have had a 6500 RPM engine that hits harder, all the time, with less valvetrain stress.
@@Dr_Xyzt Well you've clearly demonstrated that just because a thing is understandable, that doesn't mean that you can understand it.
@@stephendee7839 Would you mind elaborating there? I don't blame you for coming to that conclusion.
-- Where I'm from, people tend to buy stuff and slap it together. So, a given cam/valve/pushrod package might be stable enough to not drop a valve, since it's a validated kit. They fail to realize though, that they get a long duration cam on a stock intake that pushes the practical operating range beyond where the intake resonates. That's a simple computation of percentages, grade-school mathematics. That, is what I frown on.
Built in 1981- 340, X-heads shaved 60 thou, port matched, mild porting and polish, Holley Street Dominator, 800 Thermoquad, 302dur. .468 lift solid lifter 104 degrees overlap and Hooker competition headers, balanced bottom end, for my 69 GTS Dart, line lock, 4:10 Richmond gears in an 8 3/4 with an A833 shifted by a Hurst Ram Rod shifter, and line lock, this was my toy for the streets back then. Was guesstimating around 425hp as dyno's were very rare here in Canada back then.
Thank you Richard for the video. I agree with the assessment of most people don't understand calculas before Trigonometry. But!!, a good teacher can explain valve events in a way that someone could understand in relation to why the event is happening. I appreciate your videos very much. Thank you
Ah, a tasty video to pull us non turbo crowd back in. Thanks for the bone Richard 😀
When I was in high school everyone just claimed they were running a Three Quarters RACE cam! Everyone would nod their heads and go that's pretty extreme man! Pretending that we knew what they were talking about
Yeah, that one was popular where I grew up. Never knew what that meant. 3/4 of what? Only has lobes for 6 cylinders? I suppose it was some duration number 3/4 of the way between a stock SBC grind and the Duntov 30-30. (Whatever a 30-30 cam is. Never knew that either.)
@@andyharman3022 from what I was taught back in the 60s and 70s you could order a full race cam from the factory dealership or a smaller three quarter race cam depending on what type of street drivability you wanted.
@@andyharman3022 3/4 vs full race, that came about when there werent many cam grinds. The term 30-30 is a reference to the solid-lifter cam's valve lash settings assigned by Chevrolet.
@@cuzz63 yes sir the old Duntov performance!!!
3/4 cam, the day you showed up at the parts store 1/4 short on money.
Richard, I'm by no means a pro when it comes to camshafts, however, I do know enough to get me in trouble from time to time. So... I'm putting a simple, but stout pump gas 10.2 to 1 (should be around 8.4 dynamic), great flowing aluminum AFR heads, 350 SB Chevy together with an old grind hydraulic roller camshaft from Comp Cams (known as the "306" grind). The cam specs are "roughly" 230/ 244 at .050" (Actual according to cam card is 229/ 245 degrees) for duration and a lobe lift of .340/ .361 ( .510/ .540 with a 1.5 rocker) with a wide LS of 112 degrees advanced 4 degrees from Comp to 108 degrees). Also, for you to know is that I'll be using ported and cnc"ed Corvette rams horn manifolds with a very high flowing 2 1/2" exhaust. After explaining all of that, my question is this: If I run a 1.6 ratio rocker on the intake side and a 1.5 ratio rocker on the exhaust, I'll have a .544/ .540 lift with the supplied cam lobes from Comp. With the 229/ 245 split in duration, shouldn't that combo of lift work just fine with that duration and a smaller exhaust? Also, would increasing the lift to .544" with a short 229 degree duration still be easy on the valve train for street usage? Any help or thoughts would be appreciated. Thanks in advance, Jim Howard
IT WOULD LIKELY BENEFIT FROM 1.6 ON BOTH-JUST NOT SURE WITH THOSE MANIFOLDS
One valve event that is very important to know is when the intake valve closes. Once you know that you can use a dynamic compression ratio calculator on the internet to determine what static compression ratio will give you the best performance depending on fuel octane.
there is a lot more than a simple dynamic compression calculation to determine power or detonation threshold
@@richardholdener1727 of course there is. I was just pointing out that valve events can be helpful to the average Joe.
You have to match the lift to the airflow of the head. Then go with the higher duration mixed with the lower LSA. That will maximize power
The knowledge drop in these videos is just exactly what I need.
Cams are a great way to make power just remember there is a give and take . You will give up low in power for high in power on most stockist engine. Just remember don't give up too much squeeze with a large intake duration because you give up too much low end power.
Richard, part of learning is learning who to listen to, who knows what they're talking about and who was full of b*******. But you have the truth backed up by the Dino and that's very helpful.
Thank you very much for speaking the truth
Quote of the Show.
"Some guys notch the valves so they can install bigger pistons" RH
We gotcha! 👍
IT'S TRICKY-BUT CAN BE DONE
Its all about the combo, and you can run a LSA of 108- 110 which is considered tight with Nitrous and make great power. Some blower companys like 110 LSA to make power over 114 , plus helps with cooling the exhaust valve. Engine masters did a comparsing between a normal 110 LSA cam and a spec blower cam for a supercharger setup and the difference was minimal..seat of pants wouldnt tell the difference. Its all a selling marketing bit. Richard is correct for the most part. As Richard says this is the basics. There is more too it . cubic inch , bore , stroke, head flow, valve dia., compression. I learned alot from Dave Vizard, Bill Grumpy Jenkins, Warren johnson and Mike Jones . LSA is not the most important number , its just a fraction of the big picture. Plus LSA only changes the power range by 500 RPMs up or down. MHO...🤔
Well.....what is the most important number since you know?!?
Thanks Richard for the video! This was very informative for me as I’m learning to figure out on how I want to build my motor💪🏼😎
I know this for fact....Chris Straub spec’ed a HR cam for my 454....it rips, big torque. I stumbled across Dave Vizards cam calculation and crunched the numbers for my engine....Vizards numbers matched the cam that Straub spec’ed for my BBC..... Coincidence? 109 LSA engine loves it....
motors don't love LSA numbers, the respond to valve events
@@richardholdener1727 What’s the mathematical equation to determine each valve event? It’s physics, fluid flow and pressure waves moving at the speed of sound adjusted for temperature. There has to be some associated math whether pure theory or empirical because some folks use some sort of model to spec cams. It seems proprietary, but surely some mechanical or civil engineering professor has derived something that has been made public. Are you aware of anything considering your large network? You do a great job with all your testing and sharing of information! Thanks!
Vavle events is how i picked the cam for my twin GT3582 4.8L. The "normie" cam specs are 200/216 .580" 114 +4. Would i have ever picked this cam based on those #s? HELLL NO. It even has -10° of overlap. Does it work? HELL YEA, better than could have ever hoped and it idles like stock. Traps at 142mph in a 4000lb car at 27psi of boost. Best part is the drivability.
a 200 cam should idle very nice
I'm seriously going to buy the Truck Norris cam kit. Just so I can tell people, "I have the Truck Norris kit in my Sierra!" 😂 Obviously, I'll replace or upgrade a few other parts while I'm in there, but this *_will_* happen in the very near future!
Take a stock lt1 5.7l the cam is ( lift) intake .447/.459 exhaust and int .205/ .207 exhaust (duration) .05 . If you divide 205 stock intake by 300"hp" by 205 int cam you get = .68 as a ruff value of what represents in this eng sbc meaning the numbers on the cam to achieve 100hp. You can take the 300hp divide x 205 = 1.46. (example 268 intake duration cam times that 1.46 = ruffly about 391hp cam efficiency base without your other power adders like heads/ intake/ exhaust/ fuel or piston compression could be more then 100hp on top) to put ppl in the ball park provided you have the matting components easy recipe. The way I guess the right cam for the job is all the numbers matter, first the {HIGH LIFT adds AIR good for short max compression} HIGH EXHAUST moves AIR OUT, faster rev and piston, DURATION How LONG STAYS OPEN FOR FUEL/AIR SIDE TO SIDE LOB, LSA LOWER the number the more. RUFF adding to the drive ability and timing to add more fuel between and also poor gas mileage. Meaning a cam with a 268 intal duration and thought good exhaust lob as well should build you a race engine that will put you over 400hp likely and under 500hp crank unless you really spend and this is a presumed 4 bolt main.
Otto cycle is 720° of rotation.
4 Strokes-5 Events
Intake, Compression, Ignition, Power, Exhaust.
Ignition starts a few degrees of crank rotation before TDC on the compression stroke and completes so many degrees after TDC on the powerstroke.
Cams only rotate at half the speed of a crank, timing is necessary
Overlap is when both valves are open during exhaust/intake stroke for scavenging and cooling of the cylinder and head.
The theoretical ideal charge which is called the stochiometric value is 15:1 however it causes engine temps to be too high so for optimal cooling is 12:1.
Using the wrong cam can cause valve overlap to be reduced meaning valves open too late and close too early so cooling/air intake and heat/exhaust are not fully realized in the cylinder. Too much cylinder heat can cause preignition and detonation.
Lift is only how far the valve is off its seat. Duration is how long the Valves are off their seats.
Increasing overlap can also allow unburnt hydrocarbons into the exhaust wasting fuel energy and polluting the environment.
Richard, thank you.✔️💯🇺🇸🇺🇸🇺🇸
Hey Rich, could I get a cam spec for my XYZ! Did you see that coming?!? 🤣🤣🤣
I'm used to cams we used in dirt track engines with 106 and 108 LSA. I noticed that everything you use is 110 to about 114. My cam is 107 LSA but it's still only about 500 lift. The duration is about 235/249 at .050. I know the idle will be rough but will it do well for power with a 5 speed in a very light car. It's a 360" SBC with flat tops, 0 decked and Dart Iron Eagles, 64cc. And the intake c/l is at 102° it will be run with a dual plane air gap and a 750 Holley.
For the reverse cam you might do
224/220 (218?) and step up to 224/232 or something of that kind.
I guess you would keep the LSA constant for it to be a equal comparison?
Putting a big cam in without headwork is like building up your body without building your brain, you cant do the things you should be capable of
Wow, that's deep
Lift of cam can relate to head flow... Suggestion only. Where a head flows maxs out the cam lift should be close to that .
I don't agree everyone should chose their cam based on head flow (90% of us don't use all the available head flow)
@@richardholdener1727 Richard. I agree but in most cases of race situations you want max lift to be as close to max head flow as possible . can we all afford to do this hell no but what I have been taught is for example your head CFM maxs out @ .650lift@ 300CFM. For maximum power you want cam lift as close as possible to use as
much CFM as possible. On the other hand using the same head but the cam lift max out at .580 and your trying to run max RPM to achieve max power a better flowing head will help were the cam falls off .
@@richardholdener1727 The heads are the lungs of the motor and the cam is the heart pumping the blood flow .lol
I would love to test David Vizard's 128 cam formula. LCA = 128 - ( CID / 8 / Int. Valve Dia. X .91)
right off the bat, lift is a huge deal. you can over lift or under lift your camshaft. Flow testing the cylinder head will determine where the lift needs to be. if the lift is too small, you will starve the cylinder, if it is too much, you will lose your flow charge, and acctually decrease performance
no
um... yes @@richardholdener1727
I'd like you to talk about valve events and what effect that has - intake exhaust open and closing and also ramp rates fast open slow close and how long does it stay on the nose etc and rocker ratio changes like from 1.73 to 1.8
MAGIC VALVE EVENTS?
It's magic it what you try works :) guess it's about optimising what you have, like trying to match the cam to heads you have. Maybe your heads are a little to big for the combo you have so by changing open and close points might see some gains, same if they're not big enough or flow poorly in the low or high lift - what changes can you make to improve what you have ? You're not trying to find a 100hp every time just improve what you already have cheers
I'd like a rocker ratio changes that would be interesting
What duration should a cam be when drag racing? In what degree should it be ? In what lift should u have ?
I forgot to ask while live....
I had mentioned the LS9 cam, but forgot to mention that it would be in a 5.7L punched out 5.3/4.8 and ported LSA Blower. Since upgrading valvetrain anyways, would 1.8:1 rockers be a worthwhile application ? Not to band-aid a bad cam choice, but since rockers are a viable upgrade anyway. The bottom end being soft will help power management on bad launch/no prep surfaces, while leaving everything for the top end and still a tame street vehicle if/when needed.
YOU NEED LOTS OF VALVE SPRING WITH 1.8S
I have a 07 suburban Iam putting a 6.2 truck motor in it like to get the best low in tq out of it to pull a boat it has 456 gears but the tires are 33 inch tall it tacks around 2500 on the inter state
275 duration at .050 and 1.00" of lift lets party!! :-)
I was asking what cam do you think would work best it does have long tub headers and no cats to
I have a 86 f150 xlt lariat stock block .060 over dome pistons stroked to 352 cid with edelbrock heads roller rockers long tube headers and an 850 DP and a edelbrock intake and a lunati cam i will get a list of part numbers for you and see what you think as far as power output with VP110, and E85
LUN-20310525 - cam
EDL-77179- head
942-1-94195BE.06 - rotating assembly
EDL-7121- intake
HOK-6907HKR - Headers
Stop with the quality content I can’t download it all into my phone 😂
👀👀😳😳😳Damnnn 260 onna Turbo Busa??... Wheewww
Hello Richard, my name is Percy i’m running a 496 bbc with aluminum rhs 119cc, 320cc heads also have srp high compression dome pistons 12.5:1 compression but that compression is with 118cc heads and I’ve got 119cc and my cam is a 299th big muthar thumper hydraulic roller cam kit by comp cam and a rpm intake plus 850 double pumper. Cam card show duration @ .050 int 243 ex 257 lobe lift int .3350 ex .3260 lobe separation 107.0 rpm 2300 to6100
Bummed I missed this Richard.
I missed it live too but I’ve watched it on replay twice now great in-depth info.
@@daimyo_one 11111111111111111111¹1
@@daimyo_one oops
@@nathanjenkins8284 Your good
However they match the numbers with the custom cam cuz the 292h isn’t the one
Richard, would you recommend a normal split pattern cam over a single pattern cam on a turbo LS? Grand National's cam run a lot of single pattern cam and run in the 10's.
Richard, I have an unusual motor, a 99 ram 2500 v10. I recently had a cam reground by crower because there were no available new cores. We were able to get 216 at .050" and .478"(single pattern) on a 1.7 ratio with a 110lsa. I also did my first port/polish (more polish) on the factory heads and had 2.02 intake valves installed (factory 1.92). The upper and lower intakes were both polished with the throttle body opening cnc'd to go from a twin 47mm to a single 56x108mm with custom matching throttle body. I was wondering what you think on this combo. The truck is lifted with stock 1400ish stall and all it is used for is occasional towing and off roading so torque was the primary concern all across the power band, it seemed to fall off at 4000rpm and factory shift point/redline was 4500rpm, this is documented in every dyno of one I could find as well.
216 @ .050 SHOULD HELP RPM
Oh boy I have been waiting for LSA for turbos, because it is the most important figure
46:00
ive ran a few cam's in my ls1 from stock 99 camaro, 04 ls6 cam, currently a comp 283r, but i really miss my gm hot cam it was only a 525 lift with a 112 lsa sounded amazing drove great with my 6 speed and it even passed ca smog
The Hot Cam is a good compromise at 219 effective. Adds 50 hp.
Would you say that, in general, a motor with limited head flow as the bottleneck (like, say, a 3800) benefits more from a cam with narrow LSA? That has always been the thinking in the Buick turbo 6 crowd, and many of the cams reflect that, with small duration numbers and narrow lobe separation angle. I've seen it work on my Dad's Buick 430, which runs better than a low compression n/a motor with headers and dual plane has any right to.
The odd thing is, it seems like all of the 3800 cams available are generally 113LSA or wider. I'm wondering if it would be beneficial to have a custom grind done on a 110 center to maximize the area under the curve. I'm not after peak horsepower as much as I would like to see strong torque, quick spool, and good drive-ability, while making reasonably good power without revving it out much past 6000 rpm. I'm trying to have the best of all worlds.
what you do to the cam (narrow lsa) has the same effect on a motor with good head flow (more low and mid-range power)
Love this, always talking about my buddies about optimizing a new cam on my sbf 383w street motor, thinking about raising static compression 2points to 12.5:1. Running 248/256 at .050 108lsa .720/.688 lift kaase p38 heads. My Erson cam card has the cam timing events but would like to tweak. Running a 210 cranking pressure. Trying to pick up another 50-75 hp. All N/A power
The generally accepted rule for adding compression is that one full point of compression can add between 3 to 4 percent power. So 2 pts would be at best 8% increase in power.
@@littlevman2997 Just have a stick car. Steeper gears and run good manual brakes like willwoods :)
Boom no need to worry about engine vacuum lol.
All this is great. Comment you have to Match cam to head makes sense. However with not experience where is this calculations located at. I have a 383 280 cfm heads .590 left after 1.6 rockers. 227/233 .560 cam Where do I go to see how much I’m leaving on the table do to cam? !!!!
bigger cams make more peak power but sacrifice low speed power-its not how much, its where you want the power to be. Your heads can support 560+ hp, but that 227 won't make that.
@@richardholdener1727 thank you for the reply. It would be cool if head companies did testing and said. This cam made this hp/tq with our “” head. So a person can make a comparison of say 5 cams.
@@richardholdener1727 I love your channel I wish I watched it before my build. I now know why they say never purchase a cam first!!!!! Pick the cam last!!
Richard, non cam related question. Have you ever ran pro topline 23° cylinder heads? How did they perform? I have a set on my mud bogger.
I HAVE NOT
can you give me the reader's digest version of what they mean when they list a 110+3 vs just a 110 lsa? and what does that do to the power production in rpm range, area under the curve, peak power or torque etc?
Back in the day people use to advance the cam (in relation to crankshaft) to get more torque at a lower RPM or retard the cam to move torque higher in the curve. Nowadays people are fancy and make the cam with the advance made in to it. So when you install it dot to dot its already advanced, etc.
Furthermore it confuses people that they always list the "+3" right after the LSA, making it seem more involved or complicated.
@@baby-sharkgto4902 - Ah, I see. Makes sense now, thanks, dude.
@@baby-sharkgto4902 thank you. i can relate to that now. we raced a 2.3 ford (dirt track) and advanced and retarded the cam for track conditions. they just grind it into the cam now.
I'm really curious to see how the smaller, median and larger size cams compare down low (3-4k rpm) when they are each run with the appropriate or equal dynamic compression. I believe dynamic compression is key to a well performing street engine and has been helpful for setting up for pump gas na applications with 11to 1 static comp. Seems like the bigger cams are being shorted by not having the same cylinder pressures down low when tested on the same static comp.
I agree. I've gotten to the point where I don't really spec a cam by duration and LSA, but by certain events.
The intake closing point needs to match your static compression ratio, engine geometry, and fuel type. This point determines dynamic compression.
Overlap is determined by exhaust closing/intake opening and is determined by intake reflected waves, application, head flow, and a host of other specifics.
This is what leads you, indirectly, to duration and LSA.
@@tadwiltman4875 Yeah your right as there is more duration you move the sweet spot in sacrifice tq on rpm, but the idea is to get the max air and fuel in the cylinder and get it out as fast ass possible. So for me I'm thinking we start with a base power we want for our build with the cam out put to be about 100hp lower then then overall end game with no power adders, find a cam with the drive ability you want and the sound your looking for ( like in If I did my exhaust on a music car would be different but for my vet bit o sleeper I need a cam that is 114 LSA or higher to be under cover and take the ol lady out. Most of thees guys are trying so hard to impress everyone with big numbers, but I like reliability best modest cam for a street beast and crazy for the guys on the track. You can get so much more out of full exhaust, valve lift, gears, stall and tires then ppl think. Caming is for big boys lol. exhaust 60hp 6 tenths , valve lift 1.6 15-22hp 2 tenths, 220gears to 373 gears 4-5 tenths , 1900/ 2800 stall converter 4-5 tenths, and good tires 3 tenths = like a 200hp conversion and 2 sec off 1/4 mile times.
Brian Tooley uses too wide of an LSA. Richard has done Dyno sessions that showed the benefits of using a tighter LSA
no
Never could understand why a person wants a PD blower and then wants to put a cam that reduces the power where such a blower shines. Then they will also do a stroker motor to increase torque. How does this make any sense????? Use factory displacement with a camshaft with tighter LSA which would increase torque and horsepower for a cheaper price than a stroker kit. Remember to try and stay intellectually consistent. I know it hard for us gearheads to do. I have a Hellcat and want to cam it. I will most likely use the Tomahawk 2.0 with 111 LSA . I'd rather have 108 but 111 is about as tight as they make for the Gen 3. I'd like 600+ lift and 108lsa with duration in the 220's.
you are not asking the same question about cams that OEM engineers (and may other cam buyers) ask
295/336 Duration, 595/595 Lift, 107 LSA stock 5.3 stick shift 4.10 gears 320lbs truck maybe lighter
Do you think that would be a good cam
provide the numbers at .050
@@richardholdener1727 234/277 . Thank you
@@richardholdener1727 do you think that could hit the valves to the piston
Any chance you could compare Comp Cam NSR Drift 233/243 54-777-11 on 5.3L, 6.0L, and 7.0L? A couple of us on the ls1tech forum are curious how the low lift but long duration would affect the hp/tq curves compared to stock and other cams. Would the 114 LSA be helpful under boost applications?
Thinking bout going like a 650 lift 190 degree in 360 duration
Hi Richard
I regularly watch your you tube channel and particularly like you LS content
I am building an ls and wouldn’t mind your thoughts on it
In short
Ls2 block 4” bore
4.125 crank
Forge Piston 6cc dome
Pro Comp ls7 heads (have checked flow 360@600 370@700)
Comp cam 256/279@50 660 lift
Short travel lifters
Factory rockers (CHE trunions) all clearance are good a little shrouding around the valves because the bore isn’t really big enough
Comp ratio about 12.5 -13 want to run pump fuel/e85
At this point will run factory ls7 manifold 90mm throttle body (will change if needed later on)
Would like to see 600+ at the wheels
Your thoughts is 600+ possible
Comp ratio
Cheers Rob
What cam would you choose for a Std 454 BBC 10:9.1 comp GM bowtie oval port heads Street strip 550 whp goal
it would need to be a big cam with those heads on a 454
I'm trying to figure out a off the shelf cam for my 4V Cleveland it's going in a kind of heavy car but it will have low gears and about a 3000 stall converter
plenty of Comp cams avail
327ci, 30 over, 462 camel hump heads, 373 posi, will a 268D & 454L cam work good in daily street drag?
what are those cam numbers?
I need help Rich, ive been watching mr vizard. I have a 91 mustang gt. Im looking to do a top end kit and get a cam w specs he would figure. Is there an off the shelf cam in regards to this? I want to keep bottom end stock. Id also like to add boost later on down the line. A na cam and boost cam recommendation would be awesome. Im also keeping it efi no carb. Any help along w recommendations are highly appreciated. Another thing whats the best intakes for these? Is it holley, trickflow, or? Thanks in advance and i now know the lsa/lca is very critical. Another question, when you set ring gap for boost what do you set it to? Is there a top end kit youd recommend?
If you want David to select your cam, go to David for specs. Yes on more gap for boost. Not sure what you mean by best intake.
@@richardholdener1727 out of your testing which intake performed the best? ie the best intake for hp and tq. ive heard the Holley Systemax is the better of all of them. what should one gap their rings at for boost? i simply don't know is all. i just figured you go by how he selects cams as well. i'll def go to him in that regard then. thanks again
So 6.2 lsa?
Cam and duration please ?
Is there a way to convert LSA to actual overlap? I am convinced you need a certain overlap for exhaust headers to really work well.
You need to know the duration and LSA to calculate overlap. You don't necessarily want overlap for every situation.
@@03c5z IE it can be a boost leak?
@@Dr_Reason excessive overlap can act as a boost leak. Turbo cars will still make their target boost either way if they are within their flow limits since shaft speed isn't fixed like a supercharger. PD blowers will often show less boost with more overlap, but it usually works just fine.
Have you ever done studies on valve seat depth (intake seat deeper than exhaust) to use overlap and exhaust draw to assist low lift flow?
I have talked about it in theory as well as different valve job angles-but no tests
The thing that keeps me confused is what LSA does to the torque curve and more importantly to me is vacuum production. My Car needs a good amount of vacuum to operate the A/C controls and the power brakes want more than I have now. I understand that a wider LSA helps vacuum but hurts low speed power. meaning for my beast that needs vacuum a number like 114 LSA would be preferable over a 108 LSA. Trouble is, I like low speed power .
More lift?
Richard not a cam question but id like to see your take on this .hey everyone first off Merry Christmas to all . i have a question im setting up my exhaust for running twin turbos and i bought the sniper efi system first off do i need to have two o2 sensors ? and second of all whats recommended location of the o2 sensors before the turbo or after on the outlet side of the turbos ? im almost thinking the outlet side of the turbos because its the very last the hot gases run through for a more accurate reading to the controller . any ideas or thoughts are appreciated thank you Bill
outlet side-two is better but many just run 1
Love you bro
Does LSA depends on the valve size to piston bore
LSA is cam, the other two are head and block
I'm. Building. A. Street. Motor. 383. 30. Over. Darts. Heads. 202. 160. Na. 1. Point. 6. Rockers. How. Big. A. Cam. Can. I. Run. An. What. Kind. Had. Or. Solid. Lifter
Is something wrong with you?
What do U Think
2 of these
on a 400 + hp .
302 sbf Drag Race Motor
T04E Turbocharger
HP BOOST STAGE III T04E T3/T4 .63 A/R 57 TRIM
Exhaust Standard Flange: T3/ T4 4-Bolt
Turbine A/R::0.63
Inlet / Outlet Diameter:: 3" / 2"
Standard T3 5 bolt downpipe flange pattern
Intake inlet & outlet: 3“& 2”
Compressor : Trim: 55
Compressor : A/R: .5
Compressor : Inducer: 50.5
Compressor :76
Turbine : Trim: 73
Turbine : A/R: .63
Turbine : Inducer: 65.5
Turbine : : 55.9
yes
If 200 cc heads are a limiting factor on a 351w, what would it like?
the stock 351W heads are not near 200 cc-but I'm more interested in flow than volume
Can you address emission issues with cam selection for chevy 350 1984 issue
you need to select an emissions legal cam
Awesome Content Brother,
Looking at BTR 219 / 239 .553/553 @ 115+2 in a LS3 416 Stroker @ 11:1 CR / 823 Heads, L94 Truck intake, LS7 Crank, Manifold, Cats, 3" exhuast, to Z06 Npp
6L80 TuTd w Stockish TQ adapted to Heavy /Lite tow 80's Land Cruiser AWD
Looking for Low End Torque to Mid Range w Throttle response thru Curve in a DD
Seems to be a "Goldilocks" fit, might also appreciate the Sound of that large Dur Split (20) on a 115 w a -1.00 Overlap
HOT ROD OR RED HOT FOR THE 416
there's another part of the equation people miss is rocker ratio
Is The cam base circle critical on cam selection? Do the small base circle cams flex more under high spring loads or is there a preferred steel to use for small base circle cams?
have not heard of flex being a problem
W/the large base circle cams like w/the LS platforms, 55,60,&70 mm base circle cams on the BBC’s
Do they tend do have more ramping flexibility as opposed to small base circle cam being harder on lifters and valve trains in general? Or does it even matter?
Building A 496 1401 compression road extra bvx3 heads I don't know what I want to use for an intake either a tunnel ram stack injection or an elderly injection I have two camshafts to choose from 1775 intake 748 exhaust duration is 286 and 295 at 50,000 would 110 lb separation or I can go to the same camshaft with 284 duration and 292 at 112 lobe separation any comments on what to do
THE 112 MIGHT REV A LITTLE HIGHER, BUT THE 110 MIGHT DO BETTER DOWN LOW
@@richardholdener1727 and what do you think for the intake dominated stack injection or enderly hat injection for my 496
Valve events only mean something to me when I'm tuning a car to get the injection timing right. Mainly so it doesn't stink so bad (common complaint when a cam is upgraded) and for the HP/TQ bump.
I have 350 sbc marine engine and i want good cam for maximam 5k rpm
MILD
Richard, can you answer this for me? If I have 2 cams everything the same but one is .550 lift and one is .600 lift or more, how will the curve change? I like my trucks power curve exactly how it is but just want to intensify it a little bit, all the way through or at least on top end. I have some to spare on low rpm. So will lift get me what I want? Or do I need to add just a few degrees, or add one or two degrees to the LSA? Truck has ported heads and intake/tb so should be able to take advantage of any cam changes
depends on cam-but lift might help it everywhere
@@richardholdener1727 it is btr stage 4 v2 .. 224/230 .558 .558 109LSA
I'm thinking of going custom with 226/232 .610 .610 109
I have the ported heads, do you think I need to increase those numbers anywhere or have an offset with the lift (example .600 lift intake .630 lift exhaust) or if you think I need a bigger split on the duration or tighten it up some let me know
@@richardholdener1727 I found 2 videos from TSP comparing the same cam, one with .550 and one with .600 and the higher lift cam made like 10 more hp and tq everywhere without any loss or dip so it seems like increasing lift generally gives an even bump across the board, similar to what higher compression does
@@richardholdener1727 I have .660 double beehive springs by the way so if u think I need to go more than .610 lift it's fine
Just curious. What do you drive?
2002 Chevy Silverado (also have a 1971 240Z and 1988 5.0L Mustang-neither run)
Have you tested the TSP Bald Eagle NA cam in an LS1?
no sir
@@richardholdener1727 Please do, I'm sure a lot of people would like to see the results.
Hey Richard I'm interested in the lunati high lift voodoo 625 625 112 219 223 ging in ported 243s 6 speed car runs 12.40s with the stock ls1 cam what kinda gain should you get with ls6 intake please let me no
what intake is in it now?
Hey Richard I have a LS6 intake
@@richardholdener1727 hey Richard what do you think of the lunati high lift voodoo 625 625 219 223 on 112 for full weight 6 speed ls1 with ls6 intake for all around street strip ? I mostly just take it to the track on weekends and the odd cruise just looks like that cam would give me the most average power
Sure, your turbo motors work with the cams you use, but n/a engines with anything over 108 lsa only make top end hp & zero torque. Thats just fine if you've got a track car with a 5500 torque converter and up. If you can't get traction from your suspension, I get it, but don't be telling everyone that just because your set-up makes max hp, that it has the most potencial on the track. No torque and you don't win races!
na engines with anything over 108 lsa only make top end? You need to test more or look at the many, many, many cams tested here to see where they make power
Tight lobe separation angles are not good for any boost applications ,especially nitrous
Depends on what you consider tight lobe separation cams. Back in the 80's-90's and even 2000's nitrous cams were grinded on a 108 to 110 LSA and worked great. He'll I think BDS or TBS blower companys prefer 110 LSA still due to one reason the cooling of the exhaust valve. Prostock engines use a wider LSA because of the higher duration of the cams. Just MHO and grumpy jenkins and Warren Johnson theorys.
Little late to the party ... 54 469 11 in a .30 over lq4 with TSP stage 2.5 317s and a gen2 7875 @ 14lbs......... 800whp .. ish?
YES-AT LEAST
Richard. Can you please skip the LS questions next time, they will never learn.
all questions deserve answers
@@richardholdener1727 I respect your time. Love your shows Richard.
Lost and bumbling
I disagree-your comment was very concise
Who cares about testing at 2000 rpm? It ain't like anyone is using full throttle at 2000 rpm. Most run a 3000 stall so why does it really matter and who REALLY cares?
Maybe those who have street use vehicles or towing applications, and don't want to downshift to have some kind of response from right pedal input.
@@rhubarbpie2027 IMO if you're building a PERFORMANCE engine, it doesn't matter. Especially if you're running a 3000 stall converter. If youre building a towing or low speed engine then the cam should be sized for lower rpm. Like the truck cams. I tuned a Denali and the owner/builder selected a stage 4 truck cam. Runs GREAT at 3000 rpm and up. But he was on a stock stall. I told him I would've run a stage 2 at the most. Now he is getting a 2800 stall and the trans rebuilt. Once that's done, it will get out the hole a lot better.
Daily drivers derp
@@shadowopsairman1583 they shouldn't worry about cam swaps then...
@@jaydubb71 maybe intensive engine modification isn't advisable for all end user applications, but regardless there are people who want different/improved engine performance and that does sometimes warrant an aftermarket camshaft.
You need a white board. Looking at your teeth does not help the explanations. They are nice and shiny, but.
I have a white board
You need to go back and figure out what LSA actually does. You are wrong in the importance. LSA should be the first thing you figure out with trying to fit a cam.
you get to pick your cam based on anything you want, I rely on hundreds of actual dyno results (lsa evaluation doesn't give you that data)
Anyone want to be my Boyfriend 😍💋 💝💖♥️❤️