how much would you have to mill off of the stock heads to have a CR of 11.1?

 

I'd like to know this too.
Probably shoulda posted it in the "Engine" section
<img src="gr_images/icons/wink.gif" border="0">

 

.030

 

well I was also wondering if it would be safe to spray a 100 shot with 11.1 compression or would you need to mix in some race gas?

 

Stock heads are 67cc chamber volume, Ls6 are 61cc. You get 1.5 cc for every .010 milled on the factory head. .030 should yield 10.8 and .045 should give 11.1, chamber mods will change thigs a bit.

It is always good to measure the heads just to make sure!

 

how much of a power increase would just milling the stock heads yeild? Does a 4% increase sound about right?

 

4% increase in RWHP?? Is that really true? I could have my brother do that in his machine shop right?? Isn't that just facing the part of the head that goes onto the block?? <img src="images/icons/confused.gif" border="0">

You can tell I'm not an engine builder huh??

 

I have always used 3% as the rule and its not RWHP. <img src="graemlins/fluffy.gif" border="0" alt="[Fluffy]" />

 

yea they just take .030 off of the bottom of the head. I believe a 4% increase is average for 1 full point of compression.