LS9 gasket compression effects
Mar 5, 2013 | 05:04 PM
#12
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From: Saudi Arabia
What are #1 and #2 thickness supposed to be???
To the OP who started the thread.
Stock GM MLS gaskets usually run about .052 + or -.001 doesn't mater if its 4.8/5.3, 5.7, 6.0, 6.2.
I do know the LS9 has more layers but I believe it is still around the same thickness. All the GM parts sites list the LS9 gasket as being .051 thickness.
If any thing the larger bore of the LS9 gasket would affect the compression ratio ever so slightly.
To the OP who started the thread.
Stock GM MLS gaskets usually run about .052 + or -.001 doesn't mater if its 4.8/5.3, 5.7, 6.0, 6.2.
I do know the LS9 has more layers but I believe it is still around the same thickness. All the GM parts sites list the LS9 gasket as being .051 thickness.
If any thing the larger bore of the LS9 gasket would affect the compression ratio ever so slightly.
.054" is 12589227 for LS2
.054" is 12610046 for LS3
the 0.058" , Im not sure , some say its a stock LS motor gasket , what bore or engine size , dont know
after looking arround , didnt find an actual part # for a .058"
Mar 5, 2013 | 10:13 PM
#15
If you still have the heads on the truck I wouldn't waste time or money with replacing the head gaskets unless the heads are already off. You could throw quite a decent amount of boost at that stock LQ9. It all really is in the tune as to how long it's going to live. I have fried more 6.0 on low boost compared to running more boost. I ran my first lq9 at 13lbs all the time and a 65 wet shot at the track and it ran just fine for years and I wasn't easy on it. Heck on SSS.com there is a member running 20+ lbs on a bone stock lq9. Only thing done to the motor is a boost cam with springs and push rods. Stock head bolts and even stock rod bolts. So unless your planning on going crazy boost I'd just leave the stockers on there. Once again the tune is the key. Really it's the heart of the truck. You can have the most BA 50k dollar motor and it doesn't mean anything if the tune isn't right.
Mar 5, 2013 | 10:30 PM
#16
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From: South Shore, MA
I agree with you 100%.
The heads are already off. I have AFR's on there currently that will be going up for sale.
I decided to change directions, and I'm using this opportunity to 'get it right' so to speak.
I really appreciate the feedback so far. I think I will most likely use the LS9 gaskets just because I figure they must be a little nicer, and if its appart then why not. I won't worry about the compression though. I don't plan on getting too crazy with it anyway... but we'll see. I'd really love to see an 11 second pass out of this truck some day.
As far as bolt on mods its really ready for this supercharger, and the cam is good but I know its not the best.
I had no idea someone was running that much boost in a cam only LQ9.
The heads are already off. I have AFR's on there currently that will be going up for sale.
I decided to change directions, and I'm using this opportunity to 'get it right' so to speak.
I really appreciate the feedback so far. I think I will most likely use the LS9 gaskets just because I figure they must be a little nicer, and if its appart then why not. I won't worry about the compression though. I don't plan on getting too crazy with it anyway... but we'll see. I'd really love to see an 11 second pass out of this truck some day.
As far as bolt on mods its really ready for this supercharger, and the cam is good but I know its not the best.
I had no idea someone was running that much boost in a cam only LQ9.
Mar 5, 2013 | 10:52 PM
#17
I agree with you 100%.
The heads are already off. I have AFR's on there currently that will be going up for sale.
I decided to change directions, and I'm using this opportunity to 'get it right' so to speak.
I really appreciate the feedback so far. I think I will most likely use the LS9 gaskets just because I figure they must be a little nicer, and if its appart then why not. I won't worry about the compression though. I don't plan on getting too crazy with it anyway... but we'll see. I'd really love to see an 11 second pass out of this truck some day.
As far as bolt on mods its really ready for this supercharger, and the cam is good but I know its not the best.
I had no idea someone was running that much boost in a cam only LQ9.
The heads are already off. I have AFR's on there currently that will be going up for sale.
I decided to change directions, and I'm using this opportunity to 'get it right' so to speak.
I really appreciate the feedback so far. I think I will most likely use the LS9 gaskets just because I figure they must be a little nicer, and if its appart then why not. I won't worry about the compression though. I don't plan on getting too crazy with it anyway... but we'll see. I'd really love to see an 11 second pass out of this truck some day.
As far as bolt on mods its really ready for this supercharger, and the cam is good but I know its not the best.
I had no idea someone was running that much boost in a cam only LQ9.
Mar 5, 2013 | 10:56 PM
#18
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From: South Shore, MA
****... who was it?
Full street trim... drag wheels/radials and a little less weight and he had a 10! Crazy.
I don't have E85 available in MA, so thats out of the question.
Full street trim... drag wheels/radials and a little less weight and he had a 10! Crazy.
I don't have E85 available in MA, so thats out of the question.
Mar 5, 2013 | 11:08 PM
#19
