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LT1 Piston Failure

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Old 02-12-2018, 05:55 PM
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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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Old 02-12-2018, 10:24 PM
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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
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Old 02-13-2018, 11:00 AM
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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.



Originally Posted by robert miller View Post
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
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Old 02-13-2018, 11:53 AM
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Billy do you have Any idea what your customer was running at the wheels with that setup?? Thanks for your time and reply..
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Old 02-13-2018, 11:55 AM
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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...

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Old 02-13-2018, 11:59 AM
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What is the typical cost parts/installation to upgrade the pistons?
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Old 02-13-2018, 01:10 PM
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650 hp


Originally Posted by John Micheal Henry View Post
Billy do you have Any idea what your customer was running at the wheels with that setup?? Thanks for your time and reply..
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Old 02-13-2018, 01:11 PM
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Around 5k for pistons.





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What is the typical cost parts/installation to upgrade the pistons?
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Old 02-13-2018, 01:18 PM
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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.



Originally Posted by Earl H View Post
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...
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Old 02-13-2018, 01:59 PM
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Originally Posted by [email protected] View Post
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?
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Old 02-13-2018, 02:40 PM
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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.
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Old 02-13-2018, 03:15 PM
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Nothing, they are very strong!!!


Originally Posted by Earl H View Post
Billy, what are you guys seeing on LT4's?
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Old 02-13-2018, 03:33 PM
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Very true, but the top ring end gap is only .012. Thats very tight for a boosted motor.



Originally Posted by Translator View Post
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.

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Old 02-13-2018, 06:41 PM
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Originally Posted by [email protected] View Post
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.
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.
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Old 02-13-2018, 10:39 PM
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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.
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Old 02-13-2018, 11:49 PM
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Originally Posted by [email protected] View Post
650 hp
Billy was he running with a meth injection? Thanks for your reply..
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Old 02-14-2018, 09:30 AM
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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 )
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Old 02-14-2018, 02:29 PM
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Yes sir he is.



Originally Posted by John Micheal Henry View Post
Billy was he running with a meth injection? Thanks for your reply..
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Old 02-14-2018, 02:34 PM
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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.




Originally Posted by Osman View Post
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 )
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Old 02-14-2018, 02:35 PM
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New pistons going in now.


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