Milling LQ9 heads?
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From: Waterloo, Ontario
Milling LQ9 heads? I'm just wondering if milling LQ9(317) down to 69cc would be okay for a boosted motor? I believe the heads are at least 71cc to begin so a mill of at least .014 would be required to get them down to 69cc. This would bring the compresion down to 9.92 ( with a .054 GM MLS Gasket)on my 02 Z06 motor( piston sits .007 out of the hole). I'm doing this to bring down the compression a half a point to make it easier to live with while on boost. It get's really hot and humid up here and my car is a daily driver so I'm just looking at doing things to be safe or safer while under boost. Or do you guys just think I'm being **** and should just run the stock LS6 heads at 10.5 compression? I was thinking of maybe getting a .065 gasket but that puts quench out of range and would actully be more likely to detonate? Oh and by the BTW the car is always run on 94 octane fuel. Your opinions are appreciated!
if you are trying to lower compression.. you should leave the LQ9 castings alone and run the smaller of the two gaskets.. that will benefit your quench area and keep compression lower for boost.. milling is going to raise your static compression ratio which is opposite of what you will want to be doing.. even with lower copression, these motors are still quite responsive off boost and lowering compression a point or so is not going to shave much in terms of power.. perhaps a few percent which is minimal considering what you are starting with and it is quickly made up just as soon as you begine building boost.
Chris
Chris
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Thanks guys-I guess I could run the heads with the stock chamber at 71cc. If I run a .045 cometic that gives me a quench of .038 and a CC of 9.91. I'm going to find a small cam that gives me a DCR around 7.65 to 7.81 to help low speed driving-what do you guys think?
