Did our 91MPH Drag Pass Destroy our Turbo Predator 670? Damage Assessment + Teardown
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- čas přidán 12. 09. 2024
- Our methanol turbocharged Predator 670cc lawn mower powered drag rail was FINALLY fast! We still have lots of tuning to do, but first we need to assess the damage from the 91MPH pass we did at the drag strip. The engine started smoking, and we noticed a lot of metal flake in the engine oil, so we decided to tear it down for an inspection.
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A note for Charles because I can tell the lash issue was bothering him: Don't worry about it. If it was right when you set it, it was right. As things heat and cool and wear inside of an engine, the lash will drift. It happens. As someone who is a lifelong owner of old Suzukis I can tell you the valve lash in a Samurai needs to be checked (and frequently adjusted) every 10k miles... And that's in a full-blown road car engine.
To preempt any issues in the future, do a quick lash check and adjustment the day before you plan to take it to the track. It only takes a handful of minutes and when you incorporate that into your standard track prep it will remove it from the list of things to be anxious about.
You're doing great.
I've never cared less about the handful of
horsetorques and revs that my 4g63 hydraulic lifters take off the table... lash every 10k miles, jeez...
@@mikescherrer4923 Right? And the dang thing only makes 60hp lmao
A dab of blue lock-tite, on the valve adjusters, helps. Feeler guages are your friends!
@@jeffman3 wait 10k miles?we also had jimnys here (with the 1.3l g13b engine) and i have never heard of that small of maintanance interval,on the contrary the service intervals here were a bit longer than normal cars.heck,the cultus sedan had the same engine and the valve lash adjustment was not this early.
@@maahingupta2424 It very well may have been Suzuki USA trying to stay ahead of the curve, but they recommend a check every 10k. Mine would always be one or two thousandths off by 20k, never enough to really affect performance but you could hear it.
I have since moved on to a different powerplant in a more modern Suzuki but I can still pull a valve cover and set the valves on an old G13 or G16 in under 15 minutes. 🤣
Maybe you guys need a little more valve spring given the higher RPMs you're running. Seems to me there might have been some valve float which made the push rod jump out of the pocket in the lifter. Great video guys, as always!
I was thinking the same thing👍
That is a good statement 👌was thinking the same thing
Yep
Basically they basically mashed the meat off the lifters and caused the engine to run as rich as possible hence why it was smoking heavily
Also that means the turbo seals are still ok it’s just the lifters that have failed and need upgraded to more beefed up ones and also while they had the engine apart they should’ve honed the cylinder walls to help if they want to really make some POWER! and at least 10 psi of boost if they don’t do the cylinder honing properly they could actually cause catastrophic failure going down the 8th mile track regardless of how much power they shove into that engine as that catastrophic failure will likely be a spun bearing or a rod poking through the bottom end. Surely those two things are bad enough.
What I am saying also that they need to set the valve lash when the engine is cold and after one pass down the drag strip where the engine has some heat in it and they will be able to run more fuel therefore more boost in effect going a lot faster and potentially running out of gear but if they go too fast then they will need to equip a parachute to slow that thing down.
Boost can blow rings out
Can't believe you guys didn't pull the pistons out and at least check the ring lands. That's a really good sign of what the engine can take. The bearings can be fine but still have a cracked piston or a stuck ring. You were already there you just needed to pull both heads to check. With the amount of oil smoke I figured you would of ar least checked them.
Yeah,I wouldn't have stopped until I found the issue.
Keep tearing it apart till it exposes itself ,and it should be obvious by some point.
Totally agree 👍
Exactly what I was thinking. It's misfiring and is smoking that usually means a broken piston or rings.
I think it would be a good idea to attach the crankcase vents to a catch can. Maybe even have the catch can drain back into the crankcase. That should keep the oil out of Ike's face, and off the track as well.
If it’s making crank case pressure and breathing.. venting it to the crank case will just not work
That's not what I meant. I was talking about adding a drain to the catch can. It's a common practice.
You didn’t check the piston rings guys 🤔 that would be the first thing I I’d check because a boosted engine can ruin a piston and or the rings if leaned out 😬
I can't believe you didn't take the pistons out and check the lobes on the cam shaft with a micrometer and do the bore and the pistons, DAMM MAN!!!
You should also check your pistons and cylinder bores, as they are the most important part for producing power. A leakdown test or at least a compression test. For now i think your turbo is big enough, it can give more than you have now. Get your fueling under controll, and not by choking your carb with socks. Ignition timing is also a area you should look in to. Both for power and releability.
I agree. The first place I would have looked with all the smoke and the dead hole, would have been a broken piston or pinched ring land. Did they even pull a spark plug?
torn all the way down and washed the block inside and out. And flush that oil cooler.
@@marcmo7138 Show me where the crank was ever pulled from the block. or when the heads were removed.
I was waiting for them to pull the heads . It definitely sounds down on a hole. If it was just smoke maybe it could be the turbo but smoke , tons of blow by and a misfire usually means a melted piston or broken ring land.
@@bowtie0069 I mean they should have torn it completely down.
Great video...
I bigger Turbo sounds great, but you have to figure out fuel delivery as well. Running socks over the air filter to get a richer mixture probably isn't the best way to do it.
Love the Slingshot, by far my favorite project
This is one of the worse channels to comment on, they don't care. I commented on the dyno video, explaining the afr they were targeting was wrong because the gauge reads lambda (converted to afr) which is the same for any fuel thus target a gas afr, not alcohol, and that the carb would flow enough fuel with e tube and air bleed modifications.
They definitely need to figure out the carb/fueling issues. Socks are just restricting the air, which is totally counter to adding the turbo. Does nobody make a small methanol carb?
@@gregwebb8939 I'm sure someone does for the right money. But the mikuni they have will work if they make adjustments to the e tube. Once the fuel goes through the jet (iirc they're at .125) it has to go through the e tube which has approximately .075 hole.
@@tblosser8921 just because they didn't reply to your comment doesn't mean they don't look at comments. They have liked alot of the comments I'm seeing so clearly they read through them. Also if you didn't comment in the first 24 hours it's safe to assume no content creator would see it.
A Vito's power jet is an easy, cheap, and quick solution. There's no way that engine isn't running lean.
You should really check the valve lash every time you take it to the track. For exactly this reason.
It seems to be the norm.
They should just throw this piece of shit lawn mower engine in the garbage and get a four-banger Busa engine or some shit something to be fast with gears and something cooler bro this lawn mower shit is ridiculous
@@lifebehindtheselens lmfao who hurt you bud?
@@lifebehindtheselens you good bro?
@@lifebehindtheselens
I like seeing how far these harbor freight products can make it. Busa motor has been done, old news
Hey guys I don't comment much but if you run hd diesel oil (Cat 10w-30 and 15w-40 i know for sure have it) you don't need to worry about the zddp additive. Just don't run diesel oil in anything with a catalytic converter or it will eventually ruin the cat. Keep up the good work, cant wait to see it do over a 100!
Yup I just found that out the other day, a guy who builds engines for Roush Yates told me he runs Valvoline Premium Blue as break in/flat tappet oil and he's never lost an engine to it
You can also buy break in oil, or several companies offer “hotrod” or “muscle car” oils with good zinc levels. Also, for an air cooled engine like that, they are better off running a straight 40wt oil.
I've used Shell Rotella in my KZ1000 for 18 years now. Since I built the new motor.
Rotella 15-40 T4.... It's not synthetic. Synthetic oil is pure shit !
@@shawnsatterlee6035 Why do you think synthetic oil sucks? Conventional oil isn't as refined and has more particles/contaminants in it, I wouldn't run anything less than full synthetic on anything with roller lifters, most of these modern engines only have like .002 or less of oil bearing clearance, why ruin that with 1980's oil quality
The extra vent will definitely help. I have found you can actually get more RPMs easier with the extra vent
Yes. This is true.
It's because engine has a "more holes" to breath out things that get through piston rings.
...why don't you somehow attach a dense mesh screen to the new vent? It SHOULD allow air to move with minimal blow-by
The extra vent should help. And they can run the vents to a catch can, to contain the oil vapors.
given the evidence in this video, they really don't need more rpm lol
Please sometime in the near future do something about that sock over the air filter. It drives me insane to see such a beautiful engine have something so janky on it. And to also hear you guys talk about ways to squeeze more power out of it when you are intentionally restricting airflow on a high rpm turbo application. Anyways keep up good work the drag rail is an awesome build.
So your good with putting this engine back together as is. Glad it's your engine and not mine. Good luck
The best way to take a big pile of money and make it small is to go racing.
It will be apart soon . Hopefully they read the comments.
Heavier valve springs to help out with valve float at high rpms
I think increased spring pressure might help. I am amazed this engine has made it this far. Considering the problems I have discovered in predator twins that are being used in normal power equipment applications. You must have got a good one. Track prep check all oil connections fuel connections and air connections. valve lash if you have solid lifters. As an old racer myself I will say Keep the oil on the inside shiny side up and rubber side down Do not Reverse :D
This one is all forged and billet stuff. about the only thing original predator is the case and jugs. Heads are a maybe... if they are original, I believe they are ported and polished by the company they got this from.
Needs a 2 step to build boost and improve the 60 foot. Check the Dynatek drl-400. I use to run one on my bike. Wire the 'clutch' switch to your brake pedal then floor the gas pedal, it will pluse on the lower limiter, set to what your belt can slip. Then release the brake to launch, also has an upper limiter if you choose to use it.
Since you run nitro, and knew it was lean at high rpm's, you need to pull the heads, and check the piston tops for burning. That last pass had all the earmarks of a burned piston burning oil in the shutdown area. Very easy to burn a valve face or seat, too - nitro burns really hot, so better safe than sorry...
They were running very lean afr as far i know
In this quick and NOT through tear down they did not find what caused the smoke. A burnt piston will do this. If they did not open up the ring gaps it could be a broken Ring Land. I'd bet its going to smoke just as bad when they fire it up.
Exactly what I was thinking, I was waiting for them to pull the heads .
For sure that was my comment, I thought why wouldn’t you check compression, if there going to go racing breaking down your rig every race is part of being a good team a not leaving a mess down the track is kind of a responsibility that comes with being a racer it isn’t fare to other teams , I’m not saying it was intentional or even negligent but they are new b’s and learning the ropes . They are on the brink of becoming the real deal . Just as soon as they get at least one complete spare setup so they can reliably race every time..
I better put my money where my mouth is and buy something at the store their going to need it !
@@allensandven0 exactly the need to get a catch pan made, and needs a good catch can set up and most importantly a better way to control fueling like an standalone or switch to blow through carb with a 1 to 1 fpr
In my opinion, you should pull the pistons and check the ring lands. You may have collapsed one or both. Boosted applications tend to do that when you push them hard.
I think it would be more because they leaned it out.
I'm thinking you may need more valve spring pressure. I think you floated the bottom of the valve train!
Exactly
I think so too. Done things similar with turbo cars.
And check the fit of the pushrod to the lifter, make sure the pushrod diameter is ok and it seats in the lifter all the way.
Spring pressure means nothing if you’re not setting valve lash the day you’re racing
Which is the reason that this is done before each race!
Do a leakdown test on the cylinders. Turbo+ alcohol+Nitro creates lots of heat and could cause the end gap on the rings to butt together harming the cylinder wall.
The saga of this engine continues. I am glad to see you're taking well care of it, but part of me will always have the ducati engine on it.
I agree start the whole thing over with Ducati as the motor. Then they would have something.
nah, bomba deere 670 two stroke + turbo
Or a Yamaha Banshee Twin stroker 400something on Alky...
But hey! Ducks can fly, too!
Guys the point isnt to go as fast as possible. The point is to push that harbor freight engine to its absolute limits and see what that platform can do down the 1/8th mile. The entire rail was designed around that engine so i doubt they will put any other powerplant in it until the predator is completely destroyed. Even then i see it being chained up to the roof in the shop as a momento
youtube.com/@HityDesign
That's why we changed the oil after every pass on the Top Fuel Harley dragbikes. And we only ran Royal Purple oil in them, as it was the only oil that still looked like oil after a pass.
Good point! Also, adding ridiculous amounts of fuel washes all the oil off the cylinder bores, and ends up in the oil, reducing lubrication even when the oil isn't yet that contaminated with debris and carbon and still 'looks' good... (burning nitro and/or methanol hardly gives any carbon deposits anyway, so takes longer for the oil to discolor)
Happy for you guys that it wasn't totally destroyed. Gotta a couple top notch mechanics wrenching on it, Ike and Charles.
That's a Damn joke!! 😂😂😂😂😂😂
Welcome to racing. You're going to work on it constantly and beauty of it. You'll learn more and go faster every time you tear into it
I'm not sure if that damaged tappet was causing the smoking issue. You may be pulling the head(s) to find more damage. Spark plugs may tell you if it's one or both cylinders with a problem. Valves, valve seals, guides and cylinder walls should be inspected too. Good luck guys and keep up the great videos! That thing was fast boys!
I'm so glad yall don't have a fake ass intro and try to be funny all the time. I hope yall never change. Some good dudes.
You might want to flush the oil cooler.
An old trick for a 22,000 rpm chainsaw racing cart, was they sharpened the piston skirts to “cut” through the oil on the down stroke... you also need some high powered magnets installed in the oil pan...
With all the smoke and metal, I'd check rings.
you guys gotta run high zinc oil in these engines because its flat tappet cams. I do this to all my motors that are driven hard and 4 stroke outboards
could also run lighter oil 0 -20w with zinc
@@optimusprimer4392 No no, they gotta run really thick oil, thicker than diesel oil. Running light oils at those power levels, the metal parts will contact each other easily, its only good to run light oil on n/a high rpm engines. Cars with high hp boosted builds run like 15w60 etc to get those high oil pressure and keeps the turbo happy.
Probably best to disassemble the engine to flush it and the oil galley...
More rpm for more power. More fuel more power! It needs to handle 10,000 rpm.
Water cooled intercooler to help keep the heads from getting too hot.
This is my favorite engine build.Always loved its sound. Keep building it until it blows and then build another even better.
Cars and cameras setting records and trends.
Everybody wants one, I want one too.
Awesome content!
You should build another one with Harley transmission.
Design and purpose build. Starting from scratch with intent to set records.
What's the plan for fuel delivery? If you ran out of fuel/jetting in the carb with a smaller turbo (and restricted intake), you're gonna need even more fuel with a bigger turbo. If it were me, id just go with a CV carb from a 1200 Sportster. They're cheap, plenty available and if jetted and tuned properly can easily support upwards of 90 HP. If you end up needing more than that, a Screamin Eagle 44 mm flat slide Sportster carb would get you there.
You floated the valves somewhere around 6500rpm. You could go to a nascar style double spring, but might need a mobile starter to crank it up.
It needs a 500cfm holley. The accelerator pump and bigger fuel inlet will let you tune it to perfection.
racing is no joke on any level love you guys having a taste of pushing a motor to its limit that’s what it’s all about 🔧 💪🏼
I think you guys need to watch boosted boiz's last video about his turboed shopping cart. They hooked up a fuel tech management system to keep it from leaning out with a fuel injector.
I actually thing going to e85 will be a good bet for you guys. It is generally alot milder on your engine components and doesn't need as rich of a mixture (Is still pretty knock resistant). It's cheaper too.
I'm liking the dragster content! Two thoughts about the engine, after each pass do a leak down test and if you're not doing it already check the valve lash
A big vent to a filtered catch can to help keep oil off the track would be great.
Possibly do vent return back to the heads to catch the oil then still have a big filter vent to atmosphere.
I think you had valve float. You might need stronger springs. You should pull the heads and check if the valves hit the piston.
I also recommend working out all the bugs on a dyno. You could dial in the air fuel mixture with an O2 sensor.
The valves were lashed ages ago and it used to run just fine. Just needed more regular lashing
@@dylanzrim3635 At least do a quick check with the borescope.
Did you guys open up the piston ring gaps for the turbo pressure? If not you may have broken a ring land. It will most likely smoke when you refire it. Good practice guys.
They did
You guys should have done a full rebuild
Ike - 25:13 - stripping a wire once w/ the knife tool on a Leatherman - learned young, "don't put your fingers where a knife may slip" - stopped myself for a moment, but talked myself into continuing, like, "nah, I won't slip"....and of course I slipped. Also to the bone. Strange part, it didn't hurt so bad; it was feeling the blade hit the bone and stop that got me. Similar knuckle, same finger, same hand, as your cut Ike lol
So what did we learn? Adjust the valves pretty regularly. Good to know
And increase spring pressure. Floating valves is hammering the push rods/ lifter
You can do everything perfectly. When perfect starts creating more power than it was intended to handle...,that's a good thing. That's racing. That's what inspires solutions and inovation.. Par for course guys. Keep at it .
Like first, then watch👍
🤣🤣🤣🤣🤣
ALWAYS! LOL
Always baby
I've been dying for this episode to come out!
Yes loving the content!👏 Y’all are great, and just gotta say the way Ike explains stuff when working on an engine is really encouraging and laidback in a good way, like that it’ll be fine kinda way. Yeah he’s a decent dude.
I don't know if anyone else already said something but if you haven't upgraded the valve springs & you're turning up way past the stock rpm that would be your valve float...........you guys are fun as hell to watch !
Out valve springs are rated up to 8000rpm
@@isaacitllbefine7231 only thing is that's rated for 8k without boost . As you add Boost / more psi there's more pressure on the back side of the valve trying to push it open making the seat pressure less. That extra pressure plus the rpm is causing the valves to float. The damage on the lifters look similar to what happens with valve float because they get hammered when they float. Also you might want to check the rings . With it having a misfire , plus the smoke and the fact it pushed out oil the crank case it seems like the rings are gone. It's just something to look at mostly since it went lean.
dang thats awesome ive been rewatching some older videos i bought a lawn mower to turn into a race mower and that gave me an idea to do a 670cc or a 420cc keep up the good work
Valve float. Up the valve spring pressure/seat pressure to extend the rpm range. Also you should pull both pistons and inspect the bore pistons and rings. Nitro can be really hard on rings.
Absolutely makes my day to see your guys project's just love the drag rail!
glad nothing major was wrong. that's been a pretty solid little motor so far
I'd love to see fuel injection done on this thing and more boost! Awesome Dragster😎
A Snyper with timing and boost control. The CVT kind of bogs on the start line, then gets up. But is it hooked up at the end.
Hi guys. Anal ex auto machinist here. I wish you had stripped the whole engine and cleaned it out. Just to make sure theres no little piles of sparkly bits hiding in a corner of an oil gallery in the block or crank just waiting to sneak out and stuff up your next run or dyno pull. Yes it happens all to often. That shit gets everywhere. And has no respect for other engine parts. Especially bearings.
Knowing your luck though "itll be fine" But i love how that thing sounds. Thought the turbo might have disrupted that Vtwin burble.
Bigger turbo…. Yes please!
Great video guys. Hey Charles don't sweat the valve lash thing. Looks like you had it right at 8,000 RPMs you had some valve float which allowed that to jump out. Maybe some springs. That thing is running really good can't wait to see the next trip to the drag strip.
I would have pulled the pistons and checked the rings
You could be floating a valve due to the RPM's. You might stronger valve springs to hold everything together at high RPM's. This and lashing the valves everytime you run it at the track as was mentioned before.
Again, I was way off. I'm sorry to all the people I made fun of fot thinking it would hit 90mph.
It did.
I respect humility.
I had high hopes of 100mph. Its going to be exciting to see that
@@ensporium8857 there is hope.
On your crank venting, instead of adding another vent, add a power brake booster valve onto the stock one. These are a one way valves that let's engine vacuum into the brake booster but won't let it flow back out.
On the brake booster valve there is a large hose barb and a small hose barb. The large end goes to the engine side.
Adding this valve as the pistons move down air flows out of the crankcase through to the valve, as the pistons go up the air can't flow back in the crank case. This creates a vacuum in the crankcase. This helps the rings seal better. This is where any power gains come from. It can also prevent oil seepage at gaskets and seals.
There are some other one way valves out there that do the same thing. They just cost more.
I tinker with Yamaha's XS650's. Through experimentation it has proven to be a help with them.
Seeing as how you added an extra vent you can add one to this new vent or cap it off.
that entire engine needs to come apart and get cleaned thoroughly but I can't lie... I'm genuinely curious as to what's gonna happen to that time bomb from your lack of basic engine knowledge. it's really the only reason I watch
Man you don't have to be so mean. But yes they should of pulled it apart. I am calling it rn it has a broken piston/ ringland which side idk but you can hear it in the video. It clearly went lean they knew it was running lean, lean + high cylinder pressures = bye bye piston. It will just smoke once they start it again and misfire.
Because you have a battery on board, use an electric vacuum pump on the crankcase so the bottom end runs a vacuum. And disconnect the recharge circuit from the motor to the battery for just the run so the vacuum pump isn't using any power from the motor when it really matters.
you need dual carbs, NO MORE SOCKS!
For Charles: the valve lash adjustment works similarly to a guitar tuner when the last adjustment you make is to loosen the bolt it will always loosen beyond that point so you have to over loosen and then tighten back up to the point where you have your lash adjusted where you need it
Love these videos where you go in depth into the engines. Reminds me the earlier days of this channel. Great job!
Leave the paper sit over night on a clean paper towel. Helps see all the metal flakes. Also turbo bearings are probably gone and let metal get back to the engine through the oil return side. Glad it wasn’t destroyed my dudes!
Methanol dries turbo bearings. You really need to go EFI and move the throttle assembly after the turbo. A blow thru can also be done, but it's ammensly more complicated system to tune. Good call on the crank case pressure! You should actually monitor it too. It tells you right away when your rings are done sealing. After you get the boost going, please revisit the secondary gear ratio. It can be close to 1:1. Boosted engine likes resistance and less revs and same goes to slow burning nitro methanol. If it bogs, leave on a brake. Let it gather some boost first.
Your smoke problem may be the carbon seal in the turbo. I would have pulled the heads to make sure you did not pinch a ring, you should put a little extra ring gap when using a turbo.
i would be worried about rings with that much metal. but you can do a leak down test for that and compression test. love the work you guys do keep it up. and not sure on meth setup but i would check on what plugs are good. hope to see 6s out of this thing. lets goooo
I'm at 17:00 and for your advice on assembly lube I suggest Vaseline. It's pure petroleum jelly so it reacts with little if anything and mechanics shops have been using it for decades. Also it's cheap and it can sit on the shelf prettymuch forever. Also for a crankcase vent you could have a piece of pipe with a piece of steel wool in it that way air can pass through and it'll at least cut down on oil getting past if not stop it. Lastly it might be a good idea to get an oil filter cutter that way you can check filters every so often, it'll be a tool that's gonna sit on the shelf with not a lot of use, but when you need it you'll NEED it.
In a pinch, local hardware stores usually have bar and chain oil, or some straight 30W engine oil. Works pretty well for assembly lube.
I never comment but i have watched from day one ..i am a drag car guy and i run twin turbos on my race car ..you need to run your crank case vents to a ketch can.. then you don't have oil going everywhere ...love all the videos keep up the awesome work
You guys should start playing with clutch weights and springs, tuning those makes a massive difference in your hole shot, shifting, rpm. Can't wait to see more of this BA slingshot👍
Best things i can recommend from my automotive experience is a rev limiter and studs in the block, side cover and heads if you plan on after action tear-downs to save the the threads in the aluminum. Also bronze g I des in the lifter bores and valves. Great work, never even thought about hopping up small gas engines before your channel, now looking at using this engine in a off road play toy.
Something to note for Ike and Charles, HIGH ZINC OIL like Rotella 15W40 will help with keeping inside the engine clean, and the high zinc will protect the lifter and cam surfaces. Also, since you replaced all the lifters, the pushrod locations do not matter at all unless there are different length pushrods for intake and exhaust like on a big block chevy and many other motors.
Charles, check the valve lash for ONE SIDE at a time. check the closed valve with the other valve all the way open.
a vacuum pump on the crank case will give you more HP as the valve lash things change under pressure. the push rod could have been a little or the rockers have changed. this is why they all do valve lash before a race.
Like some others have said it would probably be a good idea to check the rings and ring lands. Also I'd like to suggest going to a blow thru setup with two carbs. It's a little more complex, but ultimately more stable, responsive, and tunable.
Or they should just go standalone already.
I've seen others comment about the lash, I just want to add, if someone hasn't said it already, but check the lash cold, then out a heat cycle in it, check again, then you should be good! Keep up the good work fellas.
When you showed that damaged lifter at about 12:55 I was thinking your valves were floating and Charles mentions this at 28:51.
This is your warning - textbook CarsandCameras foreshadowing.
Get with GPS for some "unobatinium" valvetrain components or it's going to happen again.
That's a number up from the doodlebug bikes lately. Yowza. Love to see this monster do a few consistent, fast runs.
Pushing the edge of performance right here. How long will she last?
Make a little dump tank for the crank pressure that feeds back oil into the crack case
Maybe mount a rare earth magnet to the oil filter with a hose clamp to help catch the magnetic pixie dust.
Add a crankcase evacuation kit with a baffle , rod bearings wear on the upper first,test your valve springs, you might be over reving floating the valves. Keep doing what you do guys!
JUST AWESOME, GUYS! Congrats to you both! WELL DESERVED! See you soon!
I would get a smaller needle in the carb! I put 2 sized smaller needle when I put a 32 mm Mikuni from a 24 mm on a racing bike. That way you can get the sock out of the carb intake. WAY BACK over 50 years ago, I build motor from 2 different 3 1/2 hp Briggs and Stratton. They were different bore and stroke, so I picked out the largest bore and stroke and the rod from the little piston. Up the compression! Took the cam and cut the cam in the valve close side and the intake dimple that make the engine start easy. And put a refracted exhaust! I put it in a self-driven lawn mower, it took the variable speed just like the Predator!
Awesome runs at the track. She's really coming along. I hope no metal made it into the oil cooler. I can't wait to see how much faster it'll be with everything back in good shape.
You should probably start thinking about some aero on the rail? Even if it’s just some side covers leading up to the driver. Every little helps when I comes to drag racing.
With the turbo I would have left it alone and perhaps change the waste gate spring inside. Changing the size now will just introduce lag but also more heat and you haven’t got an intercooler so you’ll have to think about cooling as race fuel won’t take much before before you’ll need to act on cooling.
It’s a great build and I’m glad this thing is getting the attention it deserves.
Put two one way valves into the exhaust from an 80s Ford 302. Connect to the top each valve cover so the exhaust will scavenge the pressure below the rings to add free horsepower and higher RPM. You will be able to use 3/4" heater hose for the application.
You could fit a roller bearing in the front cover to help with less friction on the crank, it should be an easy enough job to retrofit one.
Keep up the hard work, best of luck with the rest of the project guys.
Cant wait to see the next runs, that sub 7 sec run is getting close
Run all vents to a catch can with a vent on that. This is also ideal for methanol. It catches all moisture in the oil. Also great for then the motor detonates.
Great job, I'm thinking that if you run that engine at high RPM and having problems with the valve lifter getting hammered by a floating valve, maybe you could put stronger valve springs in to help keep the valve train tighter, good luck. Cheers from Jacksonville Florida 🌞
Great takedown guys.....great to watch 3 minds workin together !!!..... great cam shots and editing !!.... thanks for sharing this with us !
Break in camshaft with factory springs and once cam is good and broke in then install ur stiffer high performance springs.
Look there he goes again right from the get go of the video " we might be able to add a few more HP , I'm not kidding " 🤣 Ike ya killin me lmao
Adding a catch can is a good idea. Having a lot of crankcase pressure is limiting performance, and forcing oil where it does not want to go (like on the track)...
The 670 seems prone to excessive blow by, and adding a turbo and loosened ring gaps is making it worse. Since nitro can dilute engine oil, change the oil after several runs, to avoid wear problems.
The turbo you have is sufficient - if you can make 20 pounds of boost with it, going bigger will only make boost lag worse. You need to get the launch rpm's up higher, perhaps by using lighter weights or stronger springs in the primary. You should be leaving the line at at least 3,000 rpm, to build boost early, and avoid bogging...
Make sure that you pull those heads, though - if you miss something in the top end, you might do more damage to the motor...
As you guys have a lathe, perhaps you could make some billet lifters if you can't buy some for that engine?
I've used a pipe cutter to open filters, no extra metal & quick. Have seen plenty of valve lash issues with over rev/float, just makes a tiny gap that gets exploited... (Both 2 strokes & blower motors, slightly diff displacements, lol) Y'all seem to be dialing that project in, certainly an interesting build, for us to follow! Thanx !
You guys should look into adjustable clutch Weights. You can buy adjustable ramps to gain RPM on engagement and the shift rate of the ramps for the new primary clutch.