Need help with engine damage (pics)

[CyFi6]

Well, I had done a pull in my car one day up to about 110 mph, and ever since that time the engine has been smoking from the exhaust rather badly. I had done plenty of pulls before without issue, but this time it seemed to cause something. Anyways, I took the motor apart and this is what I found. Cylinders 1-4 have these deep vertical gashes, and when I say deep I mean deep, you can really feel these things. They are only on one side of the cylinder wall in most of the cylinders. Initial thought is the pistons expanded and got too tight in the cylinder, but I am not an expert so would be great to know what happened here. Here's some specs on the engine
57 trim ~16 PSI
375 RWHP
Probe 1 mm oversize pistons
~.0038" piston to wall clearance

The car had been making this kind of power for about a year before this happened, it was my daily driver, and I didn't drive it lightly. I haven't pulled any of the pistons out of their bores just yet.

 

[mecevans]

Holy shit, your heart must have dropped when you saw that.

There is a 1'' wear mark in between the two gashes, about where the piston pin would be. Gonna guess the snap ring broke and wedged itself?

More pictures would help, but obviously you need to tear it down and find a new block.:cry:

 

[MDCmotorsports]

Im sayiny FOD damage or stuck/broken rings . Also looks like a wrist pin.....

 

[CyFi6]

Look what decided to take a trip down to my oil pan...
Can anyone explain how this happens?! 4 of 6 cylinders lost at least one wrist pin clip, and all at the same time?!

 

[bioskyline]

pull a piston and post pics, but looks like about right for wrist pin, or broken wrist pin clips.

 

[bioskyline]

nm i see the update now, incorrectly installed clips? or they didnt sit in the groove right

 

[SupraPieces]

Dude that sucks.... I am picking up a motor to part out this week, if the block is good I'll let you know... selling parts cheap...

 

[CyFi6]

I have a spare block, just do not want this to happen again, thank you for the offer though. On each piston, I installed one side spiral lock completely, then installed the rod/pin, then put the second lock in. They all were definately in 100%, was very particular about getting them in properly. #1 piston was missing both locks when I pulled the piston out. How is it possible that so many of them let go at the same time? Went from no smoking to smoking all of a sudden, didn't gradually get worse or anything.

 

[IJ.]

My guess would be the pistons are machined for "wirelocks" and not "spirolocks", do the grooves have square or round shoulders?

 

[IBoughtASupra]

Don't the probes come with their own wrist pins? So it should come with the right one, no?

 

[Raven97990]

Don't the probes come with their own wrist pins? So it should come with the right one, no?

Remember they are probes, so who knows if it would even be right. =]

That looks like they were not fully seated.

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[CyFi6]

Here's a bunch of pics of #1 piston. Hard to tell, but it looks like it is cut "square". In a few of the pics you can see where the edge of the groove is basically gone which would allow the clip to pop out. I can only imagine that this happened after the lock came loose, but no way to tell. Here's a bunch of pics, maybe you guys can get something from some of them?

 

[Raven97990]

Do you have a picture of the lock installed? It looks like the expected damage when a clip pops off.

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[CyFi6]

Can't find any close up pics of the piston/rod assembled when I put it together. How exactly do they pop out? The clips were fully into the groove, I know that much, beyond that how can one improperly install them? Do they have to be rotated a particular way (like the end of the lock needs to be in a certain position or something?)? I know they were seated because they literally snapped into place. There was an instructional video I had found online, where the guy basically pulled the spiral apart a bit, then wound it into the groove. This is what I did using a pick tool and it seemed to work well. If it was just one single one that popped out, I could understand that maybe I somehow screwed one up, but with so many of them popping out it has me wondering.

 

[IJ.]

Did you expand the lock before you installed them?

 

[Raven97990]

That's what I'm trying to figure out. You either really mucked up or there is a design flaw of the piston. The wrist pin fit between the locks pretty tight? You couldn't move it an excessive amount?

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[CyFi6]

http://www.youtube.com/watch?v=VZN5eujqFiI
This is essentially how I put them in. Cant remember how tight the pin fit, I will pull #6 piston which appears to have no problems and inspect how tight the pin is between the locks.

 

[IJ.]

I stretch em out quite a bit more than that and have never had a failure like yours..

 

[Raven97990]

I stretch em out quite a bit more than that and have never had a failure like yours..

Even still- they shouldn't pop out so severaly. Either the locks are too small or the pistons may machined off. Guess we will wait for piston 6 to see, but I just can't see improper install at this point, they aren't that tricky.

Also that's tacky music in that video lol.

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[90T04]

Of the pistons that only lost one lock, were they all the same side? Were the locks sitting in the oil pan undamaged or were they chewed up? Can you post some pics of the locks that popped out?

I am running the same pistons, but with eagle rods and a holset hx35 at about 15psi. I put the locks in using the same procedure as that video. Havent had any issues yet in approx 3000 miles since the build... How many miles is this since you built it?