How the Summit Racing Cam Timing Calculator Works
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- čas přidán 4. 07. 2024
- The Summit Racing Cam Timing Calculator converts duration, lobe separation, and advance into the four individual timing events that will ultimately dictate engine performance.
You can also tweak any of the four events in the calculator to learn what the resulting duration, lobe separation, and advance would be under the new conditions.
No matter what engine or application you’re building it for, you can quickly compare specs and how they differ under different running conditions.
www.summitracing.com/newsande... - Auta a dopravní prostředky
Hello from Australia. I have a HSV WK Grange with an LS1, fully built with a HTV1900 blower. Decided to stroke it to 383 and put a new cam in (currently running the stock cam). Was thinking of 220/236 with 113.5 LSA +2. I was trying to work out why the calculator was different to Wallace Racing's calculator but it was because my phone wasn't displaying it correctly! Thank you for the calculator and hopefully the build doesn't take too long and makes the daily 2.2t car boogie!
Thank you for watching, Von!
This calculator has been extremely helpful, especially as things get a little more complex with dohc engines like my 5.0 Coyote.
Thank you for watching!
Please ask if it is ATDC after the top death center. BBDC is the top center bottom and ABDC is behind the center bottom and BTDC is ahead of the top dead center
Please let me know if it is correct. Thank you
Well said thanks Summit. Can you do a segment for early 351c ect, Flat tappet, Carb, low port, street & strip Mike
Would a stage 2 high lift cam be good with a 3000 stall cam?
Nice someone finally came up with a formula chart.
Thanks for the help
interesting video, is there a reason why European cars use a longer duration on the intake while domestic is the other way around?
There is a multitude of reasons why an engine designer may use a longer or shorter duration on their design. Anything from expected power output to intake manifold design or even air intake components.
VERY GOOD VIDEO
Thank you for watching!
im wanting to build fe390 with stock heads valve train what camshaft should i get
Hi Brian, we would need some additional information from you. Can you give us a call? 1-800-230-3030
the calculator tells you how valve events relates to duration and LSA, but it does not tell you if it will work best with a particular engine. confusing and misleading for most people. David Vizard's rule of 128 works very well for cam selection.
Exactly...
J
As long as it's an SBC with 10:1 compression.
@@aldo6192 I'm looking forward to trying Vizard's 128 calculation on my current build. What you said about 108 can be said for 110 and that's about all comp offers. So why does comp speck most of there cams lsa for roughly a 305😂😂 I agree Vizard loves to ramble and get sidetracked with his stories now that he's in what his 80's now?
Great how about dynamic compression and effective stroke where is the limit on Dynamic compression
please note from several sources that say any of it cant be calculated by DCR etc. there are many other factors that can affect pump gas compatibility. from your intake valve opening degrees is where you can get your dynamic compression ishoot for8.5to 1 its right in the pump fuel zone= 7.5 to 1 minimum to 9.5to1 max and that is hot.for instance GM's ZZ350 crate motor is 195PSI that is high but the fast burn chamber gets away with it. race engines that use race fuel or additives go beyond this of course. its really fun when you do also. it creates a supercharged affect. iuse a direct head port cooling, piston top coating, and smooth all the sharp edges this is the real reason for polishing because polishing does not create more flow. it evens the heat dissipation and heat is the power in a combustion chamber and cylinder, this creates the pressure. you want 195 psi in a fast burn or modern performance head chamber at max. if you go direct head cooling know what your doing. basically if you get a hot spot in the chamber or a sharp edge, this is what causes a ping. that is bad. do not operate an engine that pings under those detonation conditions. ican blueprint an engine for you. or spec your cam matching your dynamic compression to run the most on pump gas also varies with altitude and how good you fill the engine cylinders. Really its going to matter what cylinder pressure actually measured is. you want 175 PSI minimum, to 190ish PSI
@@7REDDRACO7 Excellent information. I learn a lot from CZcams comments like yours.
Thanks!
@@7REDDRACO7 very good info. I had a 6 liter LS with a fairly large cam at 238/242 duration and Trickflow heads with 10.9 compression ratio and I was very surprised to find 220 PSI with an accurate compression gage. I thought a cam timing of that size would produce much lower....... but it didn't. All was good tho. 93 pump gas only.
That is the Cam Motion Camshafts Cam Timer. Your welcome.....
This is a major point when one makes a negative valve overlap because of the 0.050 standard start lift. I just doesn't work. This is why always use advertised lift at .006 start lift.
I used to drive Uncle's F250 with rebuilt 460 and cam advanced 4 degrees. That truck would haul ass. Won many drag races in Edmonton. Easily 100 mph in three city blocks.
So what if your rpm is very low
What cam can I use on my 95 tbi 5.7 chevy without having to tune my ecm ?or change lifters and springs
Stock
@@brandon_907 it has a stock one but I just want something a little bigger
Any cam change requires a retune. There are a few cams on the market that you can use stock springs with though, but it's a lot of work to put in that new camshaft only to gain like 5hp from that small cam
CCA-12-249-4 will work fine with your stock TBI and springs.
www.summitracing.com/parts/cca-12-249-4
Can you guy,s do a cam comparison with muscle car engines, not LS plastic motors please,
I don't know how or why but the calculator is incorrect with the "modified" LS1 cam. It should read 1.5 advance not 3 advance. 6:56
i had to check...it should read 113.75* LSA and 2.25* advance.
( 2000 trans am) what combination of cam, heads, and intake manifold for my ls 1 product 450hp.
We would recommend the TFS-K306-485-460 and it is $3,523.79.
www.summitracing.com/parts/tfs-k306-485-460/make/chevrolet
You will have a hard time getting gains with stock LS1 intake, and smaller injectors.
Building a 351 Windsor stock bottom end other than flat top pistons, GT40 heads, the lightning intake recommended cam for better torque
Go look up Port flow, watch lift numbers as soon as the ports start losing flow increase(ie at .300 lift it flowed 100cfm and .400it flowed 150cfm and .500 it flowed 159cfm) you have reached max flow and going past that drop off is waste of adding valve spring opening pressure etc.
Then you have to decide WHERE you want it to make best torque(torque is what an engine makes, HP come from a formula that denotes how much work it does. Basically torque gets you off the line and gets you moving HP is representative how fast you will go at higher speeds.
If your in a truck, you want a fat,flat torque spec and matching converter and gear to make use of the torque up to say 5500(HP and torque numbers meat at 5250).
Now if you want a hard charging screamer car, you need MORE duration/overlap, more rpm capable parts and gears/converter and yes better heads.
I put a 355 Chevy together used some old 991 heads that factory came with 1.74 intakes, I opened them up to 1.94 , throated (bowl work under valve) raised my port guide by 5/32" (ie spot faced guide boss so stuck out less) paired it with very small in numbers cam it was one designed by Lingenfelter for use with very old Accel SuperRam fuel injection kit that was so Old it had MS Dos software to tune it so it couldn't use a sloppy cam.
That engine was a torque BEAST.
AND I used TCI Saturday Nite Special converter and 3.42 gears in my Monza. It was like .456-. 465 lift 256-265 duration advertised and like 112 love sep. Tiny cam, more like split lift,split duration 325 HP 327 cam but in that combo I'm betting it made every bit of 450lb ft of torque.
I even used Edelbrock Scorpion single plane air gap intake and 600 Carter carb(it really did love the 780 Holley I later installed. Still.
GT 40 heads have a sweet spot in flow, use a truck intake and they can scream on street
Where do you find the cam calculator on the summit site
Yea I had to Google summit cam calculator because I couldn't find it on mobile. I found it pretty useless myself. Would be a lot more useful if it would let you use different lobe profiles because not all lobe centerlines are dead center of the open and close.
What characteristics does a cam that offers a better gas mileage?
Lower lift...wider LSA
Is the result for valve events at .050” ?
Yes he is using the @.050" duration numbers. In his explanation of understanding cam lingo he failed to explain the Advertised vs @.050 durarion numbers. Funny, how the confusion between Advertised vs @.050 duration #'s has been going on since the 1970's.., some things will never change
Thanks
Is 263-280 duration good for a lopey idle?
depends on lobe ramp rate, a sloppy cam will lope with less duration, a modern tight efficient lobe with fast ramp rate will take longer duration to 'lope' since the cost of efficiency and more power everywhere is less lope versus duration. What engine do you have Morris, and any other details you can provide , what car, engine, compression,? etcetera then ican recommend you a cam that shall give you exactly what you want.
@@7REDDRACO7 I got a 225 MoPar /6.
A cam with 263-280 duration @ 0.050 would be a full race cam and have extremely lopey idle. A cam with 263-280 advertised duration would be a step above stock, or very mild. Barely audible, if at all.
@@7REDDRACO7 BAhahahahahaha....you have no frickin clue what you're talking about!!
Nice how you used .050 without telling us and totally avoiding the old SAE spec of .004 tappet and .006 valve vs the newer .006 at the tappet.....
The Notes here:
www.summitracing.com/newsandevents/calcsandtools/summit-cam-timing-calculator
say:
1.) For accuracy in comparisons, always use figures measured @ .050 in. lift.
2.) If opening the intake Atdc or closing the exhaust Btdc, enter as a negative (-) number.
The old 10 to 1 l48 350 engine comes to mind. Try taking out the stock cam and putting in a comp xe250h or 252h. Usually results in a ping king, that you gotta recurve ignition advance, or run higher octane. Yet the .050 intake valve closing is very similiar...
Has anyone ran a 7.0 cam in a 4.8? Any idea of how it would run? And what kind of idle?
The LS7 cam will work fine in the 4.8 and will have a noticeable idle. Just remember to check your piston to valve clearance. I recommend upgrading your factory valve springs and the trunions in the rocker arm. We offer a kit that will take care of that for you and that part number is SME-K-14300: www.summitracing.com/parts/sme-k-14300/overview/
When is this calculator handy? Degree your cam, and plug in real results. I have a cam that's off 3 degrees here, 3 degrees there...just a tad off. I pulled the cam to inspect it: no apparent damage. Yet, with new numbers in, my .050 duration was only off by less than 1 degree compared to spec, while LSA was off by about the same. Intake centerline was off, which took it from a 4 degree ground in advance to real world 6.4 and I think it will live [but it might want stall speed bumped up a notch on the torque converter].
But: you gotta degree your cam first, then use the calculator to spot possible issues. Yeah, you could do your own math [it's not hard]. Just think of this as spellczech for your motor.
I love your video but you don,t tell us if the valve events are @ .050 or @.006. Here is the problem with not having Intake seat closing numbers, you have no way of knowing what cam will work with what static compression ratio
You could use the kb/ uem calculator @.050 +15° method
I hear that 8.75 on that calculator is close to 8.25 using seat duration. That's like 170 psig /185 psia
@Joe Figueroa Smart guy. 💪
@Joe Figueroa Still a decent explanation brother.
@Joe Figueroa And to me that's okay because it creates job security and if someone wants to know more, they can ask questions. That's what I do.
I'm quite sure I'm more informed than the average guy and I'm always happy to help others. But I totally get what you're saying. What I consider common knowledge is way over most people's heads but again, that's fine by me.
@Joe Figueroa I live with the philosophy of "live in collaboration not competition".
Carl, can you please do anather video, showing us valve events gains with muscle cars engines etc; 351, 350, 360, the LS plastic motors talk is so boring giving v8,s a bad name, don't you think. Mike
If the Advance or retard is ground into the cam, then you dont need a timing chain with adjustment to advance or retard? I'm wanting to run a sloppy stage 2, I bought an adjustable timing chain, should I send it back for a cheaper one, or can I make the sloppy stage 2 benefit from it?
them to hit our target valve events. Your timing chain could probably be returned, but if you have a Sloppy stage 2 - you could possibly tune the events a little bit depending on displacement, gear, converter, etc. The original sprockets are probably in good condition and I would recommend just replacing the chain with www.summitracing.com/parts/sme-143012
This calculator is pretty much worthless to figure out what you really need. You need to be able to input your specific specs with flow numbers to get an accurate idea of what cam will work best in your application.
Wow now I’m a cam designer
beans or soup
Without knowing when your lift tops out with the amount of port flow gain your still kinda pissing in the whims though.
BlaBlaBla
Hi Carl.
Hi!
Nice video but your explanation of cam lingo failed to explain the differences between Advertised vs @.050, @ .020, @.015, or @.005 duration numbers. Same mistake most ppl have been making since the 1970's 😑
He's just making a basic comparison of valve events at 0.050" showing how that effects lobe seperation, overlap and advance, he already stated how each affects the motor, now why would he want to get into advertised duration numbers ?? Im curious what this mistake is ?
Umm... What?!
Sadly from 2030 on all combustion cars including classics will be banned
from public streets in entire EU and Scandinavia :-( In Germany the
Green Peoples Party gave order to shorten fuel supply from 2025
on by reducing all conventional fuel stations to only one state operated central gas
station per city or county. Now they want to slow down all the gas station fuel
pumps from 20 litre per minute to 2 litre per minute...From 2027 on in
the EU certain car spare parts will be banned too....as exhaust systems,
turbo chargers and even some engine and gearbox oils...California and
New York will do the same from 2027 on.... So no investments should be
done in oil burning cars any longer....They even created a new kind of
crime here, called emissions and smoke crime. :-(((
@@aldo6192 Sadly china makes the rules in EU and many states of the USA!