I was wondering if anyone could help me figure out if 59cc heads would put my compression too high to run well on pump gas. The heads are for a 383 ls6 bored .010 pistons are mahle -6cc. My cam is going to be 590 / 590 224 / 232 115lsa
heeeeeelp

 

To properly calculate your DCR I'll need the cam ICL and your piston to deck clearance. I did run some calculations making a couple assumptions and your static compression will be about 11.4:1, which is very doable on pump gas.

 

here is my specs been running on race gas but its getting expensive, i think 91 octane should do the trick whatcha think..sorry for the hijack


1999 LS-1 Polished Crank, 11.25:1 compression, small chamber heads, 550 lift Cam, Howell harness and computer,

 

im not sure where to find the ICL i havent bought it yet and Crane doesnt appear to advertise it that i have seen. i guess id have to actually measure the clearance

 

At 11.2 you should be able to run on pump gas no problem at all. Unless your tuned for the race gas, then you'll need to adjust for the pump gas.

 

What is the cam part number? What head gasket? What is the piston-to-deck height? What is the rod length?

 

You should have no issue running 11.25 on 93 octane. I'm running 11.31 with no issues.

 

Crane part: 1449121 rod length would be 7.25 if i remember correctly. i plan on using crane rocker set that comes with pushrods. (144750-16)
http://www.lingenfelter.com/store/ls1105910i06.html best description of my shortblock setup that i could find, i think.

 

Here it is with a 9.240" deck height (pistons .010" in the hole) and a GM 6.0L MLS head gasket. Deck height will significantly affect SCR, so if it's different let me know.

Calculation:



No problem running that on pump gas.

 

pistons: actually the reliefs arent -6 cc the dome is -6 cc. heads: turns out the heads werent milled so theyre 62cc chambers. deck height is stock. thanks for the help

 

The dome volume is -6cc's which means it's a relief and not a dome. This aspect of the calculation is correct.

Image updated in post above. FYI, you would be better off with a .040 head gasket because of the deck height. With .040 gaskets you get 10.97