whats the highest compression ration u can run on the 5.3Ls while still using pump gas? and or how much can u shave off ur stock heads? everything else being stock in/on the block, thanks

 

so your gonna leave the cam stock too?

 

for now yeah, im be getting a cam a little down the road i was thinking, one thing at a time if i can cause not a ton of $$ to be spending right now but

 

10.8, just a guess but I wouldn't go much past that.

 

You shouldn't go higher than a 8.5:1 dynamic CR for pump gas. DCR plays a lot larger role in what octane you can use vs. static. I think that with a stock cam you could go really high with the static CR but can't remember the exact equation.

 

There are a few good dynamic compression ratio calculators on the net...I think I have one bookmarked on my computer at home (I'm at work now)...I'll try and check tonight. As strokerace03 mentioned, it's the dynamic compression ratio that you have to worry about...if you go with a big cam with a lot of overlap it will bleed off pressure and allow you to run a higher SCR...

 

Also how you tune makes a big difference too. My old LQ9 setup had around 11.5 static and if I remember correctly around 8.5 dcr and depending on how aggressive or weak I tuned the timing I could run 87 no problem.

 

Please see: https://www.performancetrucks.net/fo...d.php?t=369863

First two links

 

What does the <TECH ONLY> link have to do with this?




j/k



Good info in those links!

 

Definitely good info....too often the stickies get overlooked...