Fireball

iTrader: (21)

with stock pistons, stock headgaskets and 5.3 heads (with the valves unshrouded)...I'm looking for estimated compression ratios with

I just saw that .015 on these heads resulted in ~60cc which was approx 11.3. what would .040 result in?

thanks <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

<small>[ May 29, 2002, 08:14 PM: Message edited by: Fireball ]</small>

Jason99T/A

iTrader: (21)

Brian, your compression ratio will be approx. 11.9:1 if you mill the heads 40 thousandths.

My old GTP stg 2s were milled 15 thousandths. This resulted in 59cc chambers.

Jason99T/A

iTrader: (21)

Oh, don't forget to account for the man-made valve reliefs. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

Fireball

iTrader: (21)

Since Craig hasn't quite done anything like this yet...he wasn't too sure without measuring. I'm gonna tell him .040 and whatever it ends up..it ends up...

I'm figuring ~11.7-11.8 with my "man-made" valvereliefs <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Jason99T/A

iTrader: (21)

Milling the GTP stg 2 5.3l heads 50 thousandths resulted in 54cc chambers. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

VINCE

iTrader: (1)

I would be careful with milling too much off of the 5.3's... Mine were milled 40 thousandths and it just added to other issues I already had.. I have valve reliefs in my pistons now that brought my compression down to a reasonable place..

SStrokerAce

iTrader: (2)

What kind of timing are you running on a LS1 with 11.8:1? I this a pump gas motor, or a race gas motor?

Bret

VINCE

iTrader: (1)

Pump gas motor.. Coach is running 12.1:1 on his forged 346ci.. I would ask Jason99TA about his engine setup. Mine is still in the works..

Fireball

iTrader: (21)

going with a heavily reduced timing on the street and a more aggressive tune at the track <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Local sunoco sells 100+ octane for when I feel like doing some spirited driving <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

Jason99T/A

iTrader: (21)

Coach's car uses race gas at the track, and 93 ocatane on the street with reduced timing.

Bad Habit Bird

iTrader: (12)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Jason99T/A:
<strong>Coach's car uses race gas at the track, and 93 ocatane on the street with reduced timing.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">So does he just use the LS1edit to up the timing at the track or what?