I'm on the fence about a set of new heads...

was going to run richards (west coast cylinder heads) stage 2 L92's.. but since they cant be milled any lower than 61cc's, my -10cc piston will only yield around 11.7 SCR... not going to work with the mid 260's duration hydraulic I am looking to run.

sooooo, he has pretty much talked me into running a set of edelbrock 245's... which flow pretty good for a classic cathedral port head (330's @ .650's)

they also have thicker deck than the stock L92 castings.... which will be more forgiving with a big hit... but its a 20cfm hit from the L92 castings.. which when your shooting for 650fwhp, counts.. milled to around 58cc's, it will yield around a 12.3 scr...

so my question has two parts: will the 245cc edelbrock be enough head to get me my goal? or would a compromise in compression for flow be better?

either way, the car will be carb'd... the cam in question will be a 263/263 .663/.663 on a 110.... on LSK lobes of course and rpm will be limited to 7300rpms.

thanks.

 

What motor are you going with? Rectangle port heads won't work on an LS1. You need something with at least a 4.00" bore.

You can go with a much milder setup (cam wise) for that build. I've never used edelbrock heads before on builds, so I don't have an opinion on those.

That SCR doesn't sound right to me. A stock piston with a thinner headgasket and 61cc heads should yield around 11.3:1 or so. A stroker motor would yield much more compression and changed pistons would yield even more.

As a comparison, my 408 with 58cc heads and an aftermarket gasket with flat-tops yielded nearly 13:1 compression. I think you're possibly calculating it incorrectly.

 

let me clarify.

its a 408cui lq9 stroker with -10cc diamonds.

as it stands right now with a stock chamber 862 head, my scr is right around 11.7. I forgot the actual cc of the truck heads, but I believe its right around 61.5cc's.

I need to get my compression up into the high 12's to 13's to make this cam effective.

 

Your pistons are killing you. There's no reason to ever go with a dished piston on an LS1 setup unless you're running boost.

As it stands (rough estimate):
4.03 bore
4.00 stroke
.045" head gasket
0 deck height
10cc pistons
61cc chamber

Around 11.4:1.

If you changed to a 58cc head, it would only be around 11.8:1

If you went with a 61cc and a 4.5cc flat top w/valve reliefs - 12.16:1

If you went with 58cc and a 4.5cc flat top w/valve reliefs - 12.62:1 -- That's what my old 408 in my sig was with LS6 heads and made 530/505 rwhp/rwtq.

There's tons of ways to make power ... running a 260 duration @ .050" isn't a necessity.

 

You are doing it backwards. Get the best heads/intake you can afford then talk to your cam/valvetrain designer for the best cam.

You don't select heads based on a cam, you select a cam based on the abilities of your heads/intake and goals.

Is this a drag race application?!

 

I've heard those edelbrockjs are badass but never seen them on a car yet....