IX Block Carnage
Patrick-
I have heard of the wrist pin pulling out but I always thought it was a domestic issue and even then its still fairly rare as far as my experience. I think a massive change in piston acceleration is about the only way its likely to do it. I havent talked to Sean in awhile...about time I call him and hang out
aaron
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Evolved Member
Joined: Aug 2006
Posts: 1,427
Likes: 4
From: Sag-Nasty, MI
Wow this one looks alot like what happened to mine...
The piston that went on mine stuck at the top of the cylinder and the wrist pin ripped out, rod snapped just like yours, and the big end stayed on the crank causing more damage.
The piston that went on mine stuck at the top of the cylinder and the wrist pin ripped out, rod snapped just like yours, and the big end stayed on the crank causing more damage.
Funny this thread came back alive today! I just disassembled the rest of the shortblock looking for more clues on my failure.
Not one of the pistons showed any signs of detonation, all ring lands are still perfect, even on the failed piston. The rod and main bearings also had no signs of detonation.
Looks like this failure is still a mystery!
John-
Not one of the pistons showed any signs of detonation, all ring lands are still perfect, even on the failed piston. The rod and main bearings also had no signs of detonation.
Looks like this failure is still a mystery!
John-
I have just seen a couple four stroke dirtbike engines break pistons off exactly as the OP showed with his pics. Newer 450F's. It was summed up as material failure. One of the cases the engine was not at peak power or a high RPM level. Its like anything, there is a failure rate with any component. Unfortunately it causes a huge amount of carnage.
I think with a small turbo on an EVO running a lot of boost and torque for a long time, definitely opens the door for failures like this. Can't imagine pushing a setup at 375-400 ft pounds for 20,000 miles of hard use and expecting it to be flawless.
I think with a small turbo on an EVO running a lot of boost and torque for a long time, definitely opens the door for failures like this. Can't imagine pushing a setup at 375-400 ft pounds for 20,000 miles of hard use and expecting it to be flawless.
I can remember the torque on gas, the car was 383/355. On E85 it was 422whp and I wanna say 380ish torque, below my normal "failure limit" at any rate. Between the timing and MIVEC I keep the torque a little low and flat to avoid weird loading. I will have to go to the dyno and pull up the .drf and take a look tomorrow.
Using my 400 ft lb rule hasnt failed me yet. Johnny's car is a fluke I think, I have never actually seen a wrist pin get sucked out the bottom of the piston. I mean my car has continued at 400 ft lbs for 49k of its 55k stock block life and 9k was when it was making 575whp / 399 (more importantly 350+ ft lbs out to redline).
There might be an easier explanation on Johnny's car. The other one that huffed 1 and 4 simultaneously is more about torque induced failure I think. In it the rod folded at the bump which is the strongest point of the stock rod and disintegrated the piston. This one failed at the wrist pin and left the top half of the piston intact. Kiggly has been examing the photos but his initial reaction was it was material failure, not pressured induced.
Using my 400 ft lb rule hasnt failed me yet. Johnny's car is a fluke I think, I have never actually seen a wrist pin get sucked out the bottom of the piston. I mean my car has continued at 400 ft lbs for 49k of its 55k stock block life and 9k was when it was making 575whp / 399 (more importantly 350+ ft lbs out to redline).
There might be an easier explanation on Johnny's car. The other one that huffed 1 and 4 simultaneously is more about torque induced failure I think. In it the rod folded at the bump which is the strongest point of the stock rod and disintegrated the piston. This one failed at the wrist pin and left the top half of the piston intact. Kiggly has been examing the photos but his initial reaction was it was material failure, not pressured induced.
Dynojet. It seems 400 is fine as I went 49k at 400+ at that level and it hasnt broke and I have been far from easy on the car. We have been steadily upping the limit but just reading dyno threads that end in someone breaking 470 is too much, 430-440 is about the limit it seems, so I just use the 400 rule on stock blocks and it seems to work for us.
I appreciate the feedback John.
If Reese still had his Dynojet, with the DV holding 30lbs, we figure about 425/410. This seems to be the norm. for Cammed IX's with supporting bolt on's, and E85.
Don't mean to highjack the thread, but this seems to be typical for these threads. Why did this happen and can this happen to me. Feedback from people like yourself, really helps.
Thanks again
If Reese still had his Dynojet, with the DV holding 30lbs, we figure about 425/410. This seems to be the norm. for Cammed IX's with supporting bolt on's, and E85.
Don't mean to highjack the thread, but this seems to be typical for these threads. Why did this happen and can this happen to me. Feedback from people like yourself, really helps.
Thanks again
No this was just a really weird metallurgy problem. There is no obvious root cause, your numbers are around where my car was on the stock turbo (I was 434/399), I would presume you are safe since no one else has reported a failure like this. John is not new to engine building and looking for root causes of failure. The other pistons are det free (no pitting) no signs of aluminum on the plugs, the piston that failed still moves freely in the bore.
If it did anything the E85 would have swung to E70 and gone a half point rich. The car doesnt have enough timing in it care about E70 at 28psi (see above timing map) and the knocklight is set to 4 so if it did happen and get some hurt feelings the light would have blinked
Cliffs- The piston just broke
If it did anything the E85 would have swung to E70 and gone a half point rich. The car doesnt have enough timing in it care about E70 at 28psi (see above timing map) and the knocklight is set to 4 so if it did happen and get some hurt feelings the light would have blinked
Cliffs- The piston just broke
) stock block EVO owners, this is root cause.
Evolving Member
Joined: Jan 2007
Posts: 201
Likes: 9
From: NorCal
Yeah yeah, I know this thread is oldish, but had a few things to say, plus I've spoken with John before on the Link forums.
Hope all is well John, any updates?
Free Revving a motor is the last thing you want to do for any period of time.
Think about it.
The piston/rod only sees a load on the power stroke.
But what happens on the exhaust stroke as the crank/rod PULLS THE PISTONS DOWN.
If the engine has a heavy piston and it's freely revved and the piston flys up while pushing exhaust out of the cylinder, there is nothing other than the head to keep that piston from flying out of the engine except for your oem rod and piston strut design.
You can easily have provisions for Evo Oil Squirter machined into any 4G64.
Your Evo Block and any 4G64 that will swap into your car are essentially the same casting, only difference is the 4G64 is punched out to 86.5mm bores, and the deck is 6mm taller.
Do not free rev your engine, and do not engine brake from high rpms and you'll be fine.
Power does not break/bend connecting rods.
Excessive cylinder pressure from detonation is what will bend a conrod.
Free revving and high rpm engine braking will pull a conrod apart, or rip the bottom of your pistons out.
The pic attached is of a 4G64 machine for Evo Oil Squirters and then swapped into an Evo for use with a Brian Crower 102mm Stroker Crankshaft.
He's a member on the SoCalEvo.net forums.
http://www.socalevo.net/index.php?op...&topic=71460.0
Hope all is well John, any updates?
its so wierd i mean these things can happen not just to evos but to any car SAME EXACT damage occured on a DRY REV no load what so ever on my aunts camry 4 cylinder.
the thing had about 60,000 miles on it, she was extremely LAX with the oil changes, but the big end of the road was still free floating on the crank.
what makes these things happen? i have no idea. it would sure be nice to find out tho.
Eddie Rosado
the thing had about 60,000 miles on it, she was extremely LAX with the oil changes, but the big end of the road was still free floating on the crank.
what makes these things happen? i have no idea. it would sure be nice to find out tho.
Eddie Rosado
Think about it.
The piston/rod only sees a load on the power stroke.
But what happens on the exhaust stroke as the crank/rod PULLS THE PISTONS DOWN.
If the engine has a heavy piston and it's freely revved and the piston flys up while pushing exhaust out of the cylinder, there is nothing other than the head to keep that piston from flying out of the engine except for your oem rod and piston strut design.
Your Evo Block and any 4G64 that will swap into your car are essentially the same casting, only difference is the 4G64 is punched out to 86.5mm bores, and the deck is 6mm taller.
Power does not break/bend connecting rods.
Excessive cylinder pressure from detonation is what will bend a conrod.
Free revving and high rpm engine braking will pull a conrod apart, or rip the bottom of your pistons out.
The pic attached is of a 4G64 machine for Evo Oil Squirters and then swapped into an Evo for use with a Brian Crower 102mm Stroker Crankshaft.
He's a member on the SoCalEvo.net forums.
http://www.socalevo.net/index.php?op...&topic=71460.0
Last edited by Strm Trpr; Dec 9, 2009 at 02:38 PM.
Getting Close on the rebuild, I should have her running by this weekend.
The 2.4 beasty build:
And an FPBlack to help it breath right:
This is going to be a fun car to drive.
John-
The 2.4 beasty build:
And an FPBlack to help it breath right:
This is going to be a fun car to drive.
John-
