Building for the road course...again
- Thread starter gotovato
- Start date
gotovato
Greenie N00B Member
Pulled the engine apart. Rod bolt theory is out the window. Of course I wouldn’t have such a simple failure.
From my knowledge this looks like a hydrolock failure. Piston is gone. Nothing but small pieces left
Head gasket looks fine. block deck surface also looks fine. There is significant cylinder wall scuffing on both sides of all bores. This would suggest piston seizure which is possible. factory P2W is dumd tight. like dumb. 0.0015" i believe or less. My forged engine was 0.004" and those bores were perfect.
From my knowledge this looks like a hydrolock failure. Piston is gone. Nothing but small pieces left
Head gasket looks fine. block deck surface also looks fine. There is significant cylinder wall scuffing on both sides of all bores. This would suggest piston seizure which is possible. factory P2W is dumd tight. like dumb. 0.0015" i believe or less. My forged engine was 0.004" and those bores were perfect.
gotovato
Greenie N00B Member
temp never passed 95c. I have 10 laps that session, most were slow but when i finally made a few passes i got on it. Temp was still sub 100c(212f).
Head gasket looked mint, block deck was mint. The head i didnt look at TOO well yet but it also looked fine
I would call it piston failure. As that screenshot says they have a rev limit too
gotovato
Greenie N00B Member
8600rpm is a good bit of engine speed for a failure like this. Much destruction.
Plan is to pick up another oem long block. Hopefully Friday/saturday. Get that installed to finish the season while I work on the forged engine on the side.
I’ll run last years OEM tune which had 8500rpm rev limit. Good enough. Hopefully I’ll have a spare engine after all of this
Plan is to pick up another oem long block. Hopefully Friday/saturday. Get that installed to finish the season while I work on the forged engine on the side.
I’ll run last years OEM tune which had 8500rpm rev limit. Good enough. Hopefully I’ll have a spare engine after all of this
AYOUSTIN
Greenie N00B Member
That's totally the route I would go. Machine a bearing housing that accepts a readily available cartridge bearing and make a new hub with a thicker flange out of a low alloy steel (which might not need a heat treat depending on what grade you use), and thread it on the inboard end for an axle nut: serviceability and allows for preload on the bearing to be whatever you want.
FWIW I interface with a fair amount of Civic guys who track their cars and I'm sure a good amount of them would be very interested in a set of something like that. Happy to help spread the word when you have something to share.
Low rod ratio doesn't inherently mean an engine can't live well at high RPM. BMW's S54 engine has a 1.53 rod ratio and those thrive at high RPM for extended periods of time and was campaigned in endurance racing fairly well back in the day.
@gotovato sorry to hear about your engine woes. Might be worth looking into building a long rod K20 setup using a K24 block if you want all that RPM and reliability, probably worth a few HP on the top end too.
As for your engine failure, it's always hard to find a smoking gun when you're left digging through rubble, but in this case the telltale is in the scoring in the other 3 cylinders. The scoring is fairly circumferential, and normal cylinder wall wear basically never puts visible wear on the non thrust sides of the cylinder wall. In the majority of cases with scoring like this it's from the piston being overheated, and high RPM with a lot of ignition timing on gasoline can definitely do that, especially with a cast factory piston. This is possible without high oil or coolant temps, the only way you'd ever be able to have foresight of this failure is with an EGT probe. If you have any photos of the other pistons it may give more clues as to if that's the case here.
gotovato
Greenie N00B Member
I would agree for sure. After taking a look at the other bores and seeing the scuff marks on both sides, this definitely suggests piston seizure which is a known concern. The OEM cast pistons run such tight P2W clearances it doesnt take much apparently.
Mix in the fatigue/load/duration. I was warned by my tuner and I accepted the risk. I honestly didnt think it would come so soon though but 6 trips to the track with the extended rev limiter and here we are. It was a high mileage mystery motor off facebook as well. Bummer though, it was making some solid power.
I tossed all the pistons but i did find one with a broken skirt. Little piece was missing. Not sure if that happened before the failure or during it. I think we can definitely call this a piston failure. it expanded too much, seized up or just came apart. either or both.
I guess im in the phase of race car build here where im trying to assemble a reliable engine package. OEM clearly isnt gonna cut it and from my failed wiseco engine we learned about wrist pin failure.
Ive thought about many options, like you mention a long rod setup in a k24 block but that gets a little fancy and drives up the build cost.
I think we agree if my wiseco engine had appropriate wrist pins, that engine wouldve survived the 2 seasons we had planned.
Plan going forward is another facebook engine for the rest of the season, just keep the revs limited to the tried and true 8500rpm.
Im going to be assembling the new wiseco engine on the side here and hopefully have it ready for an end of season swap
How bad were the compression numbers? Did you get ripped off by the guy? It sucks you're in that position. Would you really just move on to a different platform?
gotovato
Greenie N00B Member
Numbers
1 - 170psi
2 - 130psi
3 - 120psi
4 - 170psi
The engine sat for 4 months but it was covered up apparently. It probably sat outside.
It may run. If it does then it’ll just be slow I guess. Or consume a fuckload of oil and smoke.
If it’s a piece of shit I guess my season is done. I’ll strip it down. Use the head for my engine build and just take the rest of the season off I guess. Sucks. I didn’t want to do that
1 - 170psi
2 - 130psi
3 - 120psi
4 - 170psi
The engine sat for 4 months but it was covered up apparently. It probably sat outside.
It may run. If it does then it’ll just be slow I guess. Or consume a fuckload of oil and smoke.
If it’s a piece of shit I guess my season is done. I’ll strip it down. Use the head for my engine build and just take the rest of the season off I guess. Sucks. I didn’t want to do that
Get a few miles on it to loosen up. I would be shocked it didn't come up some. Also might not even be that slow
gotovato
Greenie N00B Member
When I bought the car the engine was beat. 60% leak down in cylinders 2 and 3 but it actually ran great. It made no power but it ran fine and consumed no oil.
If this ends up being like that then that’s fine. End of the season I’ll steal the head for my build and good enough.
I’m gonna fire it up today I think. Let it idle for a minute. If it idles OK I’ll test compression again but yea. Maybe it just needs a heat cycle and a few miles to free up
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