How does the LS1 handle Boost? ***pics***
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From: Germantown, MD
How does the LS1 handle Boost? ***pics*** Well I took some pics of the cylinders today to show how the LS1 holds up to a year and a half of boost on a home tune(no dyno time as of yet).
A little bit of carbon build up, but the ringlands looked in good shape. In general the car ran an average of 5 lbs. When I first got the procharger on I would see 8#s. But after a while belt slip issues kicked in and I couldn't get more than 5#s. With the past few months I got the SDCE spring tensioned pullies with fixed all the slip problems. With the 3.7 pully I've seen 10#s on an accident by ~5000 RPMs. There has always been fuel issues with this car. It's boost referenced yet the FP stops climbing with the boost around 4-5#s. So on top of everything else it would run lean at WOT. With all those problems I was a little worried when I took the heads off. But I was pleasantly surprised when I saw how well the stock pistons had held up to the boosted and lean environment.
Let me know what you guys think.
Mike
A little bit of carbon build up, but the ringlands looked in good shape. In general the car ran an average of 5 lbs. When I first got the procharger on I would see 8#s. But after a while belt slip issues kicked in and I couldn't get more than 5#s. With the past few months I got the SDCE spring tensioned pullies with fixed all the slip problems. With the 3.7 pully I've seen 10#s on an accident by ~5000 RPMs. There has always been fuel issues with this car. It's boost referenced yet the FP stops climbing with the boost around 4-5#s. So on top of everything else it would run lean at WOT. With all those problems I was a little worried when I took the heads off. But I was pleasantly surprised when I saw how well the stock pistons had held up to the boosted and lean environment.
Let me know what you guys think.
Mike
is that a burn on #5 on the left hand side of the piston?
considering the history of fueling issues and the fact that they are cast pistons i would say you came out pretty good. did you happen to do a compression test on it before you pulled the heads to see if teh rings were still all good?
later
tim
considering the history of fueling issues and the fact that they are cast pistons i would say you came out pretty good. did you happen to do a compression test on it before you pulled the heads to see if teh rings were still all good?
later
tim
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From: Germantown, MD
Originally Posted by Gary Z
I think I see evidence of PV contact in cylinders 2,3 and 5. Thanks for interesting info.
-Gary
-Gary
MIke
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From: Germantown, MD
Originally Posted by NJSPDER
is that a burn on #5 on the left hand side of the piston?
considering the history of fueling issues and the fact that they are cast pistons i would say you came out pretty good. did you happen to do a compression test on it before you pulled the heads to see if teh rings were still all good?
later
tim
considering the history of fueling issues and the fact that they are cast pistons i would say you came out pretty good. did you happen to do a compression test on it before you pulled the heads to see if teh rings were still all good?
later
tim
Sorry I didn't do a compression check. As for Piston #5, I don't see anything out of the ordinary, but I'm no piston pro. The carbon build up seemed pretty uniform across all 8 pistons.
I did notice on the heads, the exhaust ports and spark plugs were slightly white, while the intake port was black. I know white is lean, but it waqs wierd how only the exhaust port and plugs were discolored.
Mike
You are definately hitting a few pistons with the valves, may be floating them or did a 3-2 misshift and whacked them at one time or another. Dont know what cam/springs you have but if its stock it was a misshift most likely..
Looks like you cracked the piston in this pic
Same thing i did...... was she chugging a little at idle or whits smoke out of the oil fill?? What ya got planned now???
Kyle
Same thing i did...... was she chugging a little at idle or whits smoke out of the oil fill?? What ya got planned now???
Kyle
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Originally Posted by kp
You are definately hitting a few pistons with the valves, may be floating them or did a 3-2 misshift and whacked them at one time or another. Dont know what cam/springs you have but if its stock it was a misshift most likely..
Mike remeber the night going down georgia ave to ledos with anthony and eric? the 1-2-3-2 shifts with tam in the back seat? thats when u were also seeing 8lbs aswell.
-Danny
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Verdad Gallardo Thread Starter
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From: Germantown, MD
Originally Posted by NA$TY-TA
Looks like you cracked the piston in this pic
Same thing i did...... was she chugging a little at idle or whits smoke out of the oil fill?? What ya got planned now???
Kyle
Same thing i did...... was she chugging a little at idle or whits smoke out of the oil fill?? What ya got planned now???
Kyle
Mike
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From: Germantown, MD
Originally Posted by 1F8TL02WS6
that sounds about right.
Mike remeber the night going down georgia ave to ledos with anthony and eric? the 1-2-3-2 shifts with tam in the back seat? thats when u were also seeing 8lbs aswell.
-Danny
Mike remeber the night going down georgia ave to ledos with anthony and eric? the 1-2-3-2 shifts with tam in the back seat? thats when u were also seeing 8lbs aswell.
-Danny
There's been about 3 or 4 times it's happen at WOT. one time at MIR I did it so bad that the car sounded like it blew apart and then cut off. I rolled through into the return lanes with the engine off. Tried starting her up, and much to my surprise, she started right up and purred like a kitten. I was really scared when that happened. Went right out the next day and bought the Pro 5.0. 
Mike
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From: Charlotte, NC
Originally Posted by buschman
I was really scared when that happened. Went right out the next day and bought the Pro 5.0.
Mike
Mike
how long u having it down, whats the plan now? 
i have about 2500mile on my set up. never less than 10psi and as much as 17psi(at least 30 1/4 mile runs at 17psi). so far so good, using good gas and pleanty of it. stock cast pistons. these things seem to be insanely strong.
Last edited by parish8; Sep 7, 2004 at 06:10 PM.
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From: Germantown, MD
Originally Posted by 00Pontiac
how many miles on that engine?
I have the heads off so I can put the stock 6.0L heads on to help with compression and detonation.
Mike
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Well you can't tell much about a piston with only the heads off. They have to be removed from the motor.
I have personally had 5 cracked pistons,my ls1 and old 5.0 combined, that looked perfect from the top and once removed from the bores the ring lands fell apart into my hands.
The best tell tale would be some heavier scoring on the cyl walls and usually the cyl will compression check or leakdown poorly.
But sometimes the ring lands just crack clean and the bores hold the piston together for a while and you really can not tell until they decide to go by-by for good.
Steve
I have personally had 5 cracked pistons,my ls1 and old 5.0 combined, that looked perfect from the top and once removed from the bores the ring lands fell apart into my hands.
The best tell tale would be some heavier scoring on the cyl walls and usually the cyl will compression check or leakdown poorly.
But sometimes the ring lands just crack clean and the bores hold the piston together for a while and you really can not tell until they decide to go by-by for good.
Steve
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From: Germantown, MD
Originally Posted by S_J_H
Well you can't tell much about a piston with only the heads off. They have to be removed from the motor.
I have personally had 5 cracked pistons,my ls1 and old 5.0 combined, that looked perfect from the top and once removed from the bores the ring lands fell apart into my hands.
The best tell tale would be some heavier scoring on the cyl walls and usually the cyl will compression check or leakdown poorly.
But sometimes the ring lands just crack clean and the bores hold the piston together for a while and you really can not tell until they decide to go by-by for good.
Steve
I have personally had 5 cracked pistons,my ls1 and old 5.0 combined, that looked perfect from the top and once removed from the bores the ring lands fell apart into my hands.
The best tell tale would be some heavier scoring on the cyl walls and usually the cyl will compression check or leakdown poorly.
But sometimes the ring lands just crack clean and the bores hold the piston together for a while and you really can not tell until they decide to go by-by for good.
Steve
Mike
After heads/cam/6speed, blower, then blower with nitrous and then back to heads/cam nitrous, 580 passes and very careful tuning my stock pistons held up just fine.
Well, almost, until the last pass with the nitrous and the piston broke, piston pin siezed and cracked the block (sleeve) on number 7
Well, almost, until the last pass with the nitrous and the piston broke, piston pin siezed and cracked the block (sleeve) on number 7
