LT1 Piston Failure
 

This customer drove this car from Austin to us (Houston) with broken ring lands. We are seeing this happen more and more. This is why we stop a 600hp with the LT1.

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ttt
 

Well may have to lower my rwhp # on the car. These dam c7 pistons no close to what the c5 & c6 stock pistons are. I really don't want to have to go into the short block of my car... Robert

These LT1s are nothing like the LS2/3. We have a hand full of those living for years at 800 at the wheels. Not trying to scare you guys. If you guys do a cam, do pistons as well.

Billy do you have Any idea what your customer was running at the wheels with that setup?? Thanks for your time and reply..

Thx for sharing. I am running a 2.9 whipple on the wife's L86 (6.2l) truck. I am very tempted to turn up the boost, but its a tow rig as well as her daily...so resisting the urge for now. Have you/other tuners been able to connect the dots on what is causing these LT1/L86 pistons to pop when boosted: too aggressive tune, bad gas, aggressive use, etc.? Again, thks for posting this...win/win for everybody, tuners/builders get more $ for builds & satisfied customers and customers get better infor re: risk/blue print for increased safety and reliability...

What is the typical cost parts/installation to upgrade the pistons?

650 hp

Around 5k for pistons.

We push the 6.2 trucks to the same 600hp as the LT1. So far no problems. The ring gaps are very tight on these engines. Thats what we think causes this to happen.

Billy, what are you guys seeing on LT4's?

I think that a LOT of the LT1 piston failures are due to poor tuning as well though with the E92 PCM platform. Very few tuners around the country are yet to FULLY master tuning with this new platform.

Nothing, they are very strong!!!

Very true, but the top ring end gap is only .012. Thats very tight for a boosted motor.

Yep, this is correct. The excess heat causes the rings to expand further and causes the ring ends to touch and then boom. Bye bye ringlands. If you boost it, replace the pistons as mentioned. And go a little bigger than stock on the ring end gap. I personally went with .022” for top ring and .025 for the second/scraper ring. I run 15 psi of boost. :)

That's a real bummer. And it makes sense, a ring gap that tight can close from expansion with enough heat and eventually expand further with no where to go putting pressure against the ringlands.

The more I read these Forced induction forums, the more it seems that C7's are a lot less mod friendly then the C6's.

Billy was he running with a meth injection? Thanks for your reply..

I had my ringland fail on cylinder 8. My car drove and ran as it did normally. I didn't even know, thats the worst thing about having it fail.

Only reason i caught it, is because i knew engine was living on borrowed time and i did leak down test when i noticed more oil in catch can and small small misfire at 50mph.. I bet you i drove 300miles with broken ringland.. ( i am guessing i broke it at track )

Yes sir he is.

Even when we do a comp test. Sometimes it won't even show a hurt cylinder. If you don't run a catch can it would blow oil out of the froont seal.

New pistons going in now.
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