Hey All,

Curious what an LS9 gasket will do to the compression on my LQ9 with stock 317 heads. I have searched using the google machine but I was having trouble finding the right answer. I know they are thicker, but I don't know exactly what that does for me haha.

Can anyone point me in the right direction?

 

zr-1 0.051"
#1 stock 0.058"
#2 stock 0.054"

on a 6.0 the CR wii jumb about 0.15 points ,

 

Interesting. Not the answer I was hoping for. Are there any gaskets that will help me move in the right direction, or will they be too thick? I was hoping to avoid any head work at the moment. I know 10.0:1 isn't a killer... but it certainly isn't the best.

 

As far as I know they are about the same thickness as stock.

 

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.

 

Ok thank you. Good to know. Maybe I will go with it just for the piece of mind that its made for Boost, even though I will not be running all that much.

I definitely want to lower compression a little, but I also really wanted to avoid the added cost of head work... damn it lol.

What are peoples thoughts on a TVS with a LQ9's compression? Would I really be that much better off with slightly less? Maybe I can get the combustion chambers of my stock 317's massaged just a little.

 

I wouldn't worry about it. If people didn't push things we'd all still be running 8.5:1 boost motors lol. I've even considered upping my comp to 11:1 in the future.

 

I really tend to agree with you... but I don't want to be naive and grenade my engine either haha.

I mean people run boost on stock TBSS'... why couldn't an LQ9 take even more abuse?

 

Back in the day they didn't have the technology we have today. They had to keep the compresion low in case the tune up wasn't spot on or if the weather changed. With all the sensors and computer controls it can take that in to account if it's set up right.

Look at Promods, there running high compression ratios and lots of boost at high RPM's.

Your only 1/2 a point higher then the average stock configuration. You will be fine! These new engines are far more efficient even with the added compression. I wouldn't worry about.

You could polish the combustion chambers to help fight carbon build up and detonation.

 

The biggest thing is your tune. Make sure you do it right or have it done right an you will be fine.