Ring gap & cam specs for a LS 408
02-12-2014, 10:27 AM
#1
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This has probably been discussed here before but since Im on the mobile app while stuck in a CE class Im just gonna ask the question to start getting some posts under muh belt.
Here's the deal. I'm in the process of finishing up my street strip car with a stock LQ4 block 408 with Weisco -20cc dish pistons, K1 crank and Rods. Running some highly modified 317's for heads and a Holley Hi-Ram intake.
I'm still looking for advice from a few folks I was pointed towards for cam specs for the combo so that is still unknown.The Turbo is going to be a Precision X275 88mm and I'll be running a massive Air to Air intercooler from Chiseled.
The goal is 1150 to 1300whp'ish thru a glide & PTC converter. So Ill guesstimate probably 20 to 28lbs of boost depending on application/class.
Im new to these motors and am learning fast but I am unsure of the ring gap requirements vs what I had known for sbf's.
Ill lookup what rings are actually in the motor now as I know that is a determining factor in what gap to use. Right now I think they are gapped at .022 If I remember correctly.
What is everyone here running? Any advice or experience is greatly appreciated!
Here's the deal. I'm in the process of finishing up my street strip car with a stock LQ4 block 408 with Weisco -20cc dish pistons, K1 crank and Rods. Running some highly modified 317's for heads and a Holley Hi-Ram intake.
I'm still looking for advice from a few folks I was pointed towards for cam specs for the combo so that is still unknown.The Turbo is going to be a Precision X275 88mm and I'll be running a massive Air to Air intercooler from Chiseled.
The goal is 1150 to 1300whp'ish thru a glide & PTC converter. So Ill guesstimate probably 20 to 28lbs of boost depending on application/class.
Im new to these motors and am learning fast but I am unsure of the ring gap requirements vs what I had known for sbf's.
Ill lookup what rings are actually in the motor now as I know that is a determining factor in what gap to use. Right now I think they are gapped at .022 If I remember correctly.
What is everyone here running? Any advice or experience is greatly appreciated!
Last edited by CATALYST; 02-13-2014 at 01:56 PM.
02-13-2014, 02:12 PM
#4
On a 4"+ bore .022 should be sufficient. As you stated, different manufacturers will suggest their own ideas. It's not uncommon to see .022 - .025 on a well worn LS engine. The high mile engines live longer under boost which seems directly correlated to the "loose" ring gap. Cylinder temps will come into play as well. Good fuel and .022 is probably fine.
