[KingLT1]

Originally Posted by 1LEornothing

Would a good tune on E60 instead of 93 oct have prevented this?

Without a doubt. 93 octane is piss water for stock compression LT1's running boost. If you want to run 93 then lower the compression.

One thing to also consider is proper crank case ventilation. Need at least a metco valve cover breather with check valve disk.

[DaveC113]

Originally Posted by KingLT1

Without a doubt. 93 octane is piss water for stock compression LT1's running boost. If you want to run 93 then lower the compression.

One thing to also consider is proper crank case ventilation. Need at least a metco valve cover breather with check valve disk.

+1, afaik LT1 can be subject to LSPI, low speed pre-ignition which is a bad form of knock DI motors are subject to under extreme conditions like boost + high compression....

[laynlo15]

I feel your pain, been there with both the front and rear seals. Costs a bunch of money for making some bad choices on too much boost and timing. We were running MS109 but just didn't have enough crank case ventilation. We actually broke number 1 and 8 ring lands. Sorry to hear that but many of us have had this happen. I would build the new short block with 10.0 compression if you intend to run boost. Ended up building 10.0 forged Manley short block. Good luck on your choices.

[Spaceme1117]

Don't want to add to your misery but I seem to have read that the piston ring gap on the LT1 is a bit tighter than the previous Gen4 LS engines and more suseptable to breaking pistons with boost.

[cjperformance]

What did your logs look like when it blew? Im curious about timing, AFR, manifold air temp, etc on that pull. May help to identify the exact circumstances/tune that spell out engine death.

I ran the canned procharger tune for a while (big mistake, lol, see my other thread), and did 93 octane for a bit before stepping up to an eth mix. Comparing yours and mine at the time might be helpful. If the tunes were similar, could point to just physical differences that make one engine live and another fail.

Im running around E50 for the most part and getting 8.5 to 9.5 psi in colder weather. Im wondering if I'd kept my 93 tune in the denser air if I'd be in the same boat right now. On the other hand it would be the excuse i needed to go through the bottom end and beef it up.

[cjperformance]

Originally Posted by Spaceme1117

Don't want to add to your misery but I seem to have read that the piston ring gap on the LT1 is a bit tighter than the previous Gen4 LS engines and more suseptable to breaking pistons with boost.

Disclaimer: this is JUST my own understanding. This has been a suspected potential issue for a while, but some other well known tuners on this board have somewhat debunked this. The rationale is that butted rings should have scored the cyl walls, but doesnt seem to be the case. Evidence seems to point to just manufacturing difference and luck.

[laynlo15]

On my Manley forged motor we build after the stock Lt1 expired we opened the ring gap up to Manley's recommendations for a boosted engine. Expansion of the ring gap is an issue for the Lt1 when you want to make more boost then GM has it set up for.

[Kerry]

Its luck of the draw on stock pistons. 2 engines I had were 11 thou on the top ring.

When the front seal blows u will have blow by from a cracked ring land between the top and second ring, most likely.

If the rings butted enough to break the piston it would not have a perfect bore. Some scaring would occur. Happened to me. I was about 600 miles from home and drove it in. All I had to do was put in a set of Wesco's. No one had a drop in set at the time . That was about 20000 miles ago at about 700 wheel. Bore was in perfect shape. No hone no nothing. just gapped the rings to Wesco specs, I did put in the ls3 front seal. Did it with the engine still in the car. Not that bad really.

Now the damage can be much worse depending on the piston and how much damage.

I had another motor with over 20000 miles on it. Sized the number 8 rod making over 600 but pistons were perfect. Put a crank and 2 new rods used all same pistons and ran perfect.

Its crap stock pistons. some are better than others. Even some stock cars have broke ring lands.

[Crazy Drywall Guy]

Well after talking to my tuner today it appears I hit 11 psi at 6800 and he seen some detonation. I purchased the P1 procharger lightly used with 3.7 upper pulley . I called procharger direct before installing the unit and they said my setup was good for 8-9 psi and with headers would be closer to 8psi. Budget build ideas please!

[wnta1ss]

As far as the ring gaps in a stock LT1, we've heard of ridiculous top ring gaps in these things, like .007" or .009", while others have reported .011" or even .015", so luck of the draw applies to some extent. Luck of the draw is because you cannot tell what you got from the factory without disassembling the engine.

[cjperformance]

Originally Posted by Crazy Drywall Guy

Well after talking to my tuner today it appears I hit 11 psi at 6800 and he seen some detonation. I purchased the P1 procharger lightly used with 3.7 upper pulley . I called procharger direct before installing the unit and they said my setup was good for 8-9 psi and with headers would be closer to 8psi. Budget build ideas please!

Ouch, yeah, I'm getting 8.5 to 9.5 psi with a 4.13 pulley in the cold weather. There was another person on the forum that was getting 1 to 2 psi higher than what procharger said too.

So unexpectedly high psi + detonation on 93 octane would likely kill it regardless of ring gap.

[Smokin19]

Originally Posted by KingLT1

Without a doubt. 93 octane is piss water for stock compression LT1's running boost. If you want to run 93 then lower the compression.

One thing to also consider is proper crank case ventilation. Need at least a metco valve cover breather with check valve disk.

Was thinking the same thing. Do you think a MM can helps in this regard?

[Joshinator99]

Originally Posted by Smokin19

Was thinking the same thing. Do you think a MM can helps in this regard?

The MM Wild can works well. I’m running that with the stock LT1 crank seal with no issue.

[Kerry]

Originally Posted by Crazy Drywall Guy

Well after talking to my tuner today it appears I hit 11 psi at 6800 and he seen some detonation. I purchased the P1 procharger lightly used with 3.7 upper pulley . I called procharger direct before installing the unit and they said my setup was good for 8-9 psi and with headers would be closer to 8psi. Budget build ideas please!

Knock sensors should stop any damage unless they are tuned wrong. With in reason of course