oem head recomendation

[purestock45]

lookin for best head for new class......carb must be 4412 untouched,3.48 stroke,175lbs cranking compression,no roller cam,flat top pistons.compression rule is the kicker at 175 lbs.heads must be oem cast iron no angle plugs....with the low compression and carb would vortecs be best choice or something like a 305 head with 1.94 valve and portwork to keep velocity up....thanks...jc

[hpontap]

A set of Vortecs would work great if everything ( camshaft/deck height/quench etc.) works out for the 175lb rule.Vortecs have a small combustion chamber.

[fast_crew]

Cranking compression rules are a joke, stuff compression to it, then stuff more camshaft to it and the cranking compression comes right back down. Vortec heads milled, good valve job, nice light weight small relief flat tops. Get in touch with a cam grinder to get an idea how much actual compression you can use, with out going to big on the cam. So he can design a cam to bleed off the compression at cranking speeds. You can try the big name cam company's...good luck. You can adjust valve lash (solid?) or cam timing alittle to dial your numbers in. Get that carb's fuel curve setup for what you are building and have at her.

[stock car driver]

305 dont flow. If you go oem vortec I would get them from a machine shop, I bought 7 head cores to get a pair when I wanted to run vortecs. It was a expensive lesson, oem they crack way too easy.

I went to patriot vortecs after that, they are aftermarket but have oem look and casting numbers on them. They have nice thick decks unlike the oem also!!

Ive got a set of use patriots for sale if your interested. 3 nights on fresh performance valve job, manley race flow lw valves, comp springs and ten degree locks. Just bolt them on and go. Flat milled to 59cc.

$600 shipped to someone on here is fine with me.

[NEracer601]

Cranking compression rules are a joke, stuff compression to it, then stuff more camshaft to it and the cranking compression comes right back down. Vortec heads milled, good valve job, nice light weight small relief flat tops. Get in touch with a cam grinder to get an idea how much actual compression you can use, with out going to big on the cam. So he can design a cam to bleed off the compression at cranking speeds. You can try the big name cam company's...good luck. You can adjust valve lash (solid?) or cam timing alittle to dial your numbers in. Get that carb's fuel curve setup for what you are building and have at her.
What if they disable the exhaust rocker when checking it? What then?

[usafracer]

Then you dont have true cranking compression.

[NEracer601]

Then you dont have true cranking compression.

There are 4 tracks here checking it that way.....sucks.

[fast_crew]

There are 4 tracks here checking it that way.....sucks.

Hmm never heard of tracks doing that, they are catching on somewhat I suppose. lol Intake valve timing events will still effect the overall dynamic cranking compression, because some of the air is going to be pushed back up the intake port if the IVC event is late enough. ( Intake valve is still open slightly when piston has changed direction and is actually coming up) I would test this your self and see how much of a difference it truly makes with exhaust rocker on and off. If it's a solid cam, try it both ways with normal lash settings, then tighten the Intake lash by .004" take readings, then maybe another .004" tighter.and try it both ways again. THIS IS FOR TESTING ONLY...The first .004 would be fine the second not so fine:eek: Please do let me know what you find because I am curious myself. I believe the readings will be close to one another with the exh. valve working or not, and that Intake valve timing will still have an effect. Wish Bill H. was still with us, he has probably already been down this road. Maybe TBRE will chime in.

[NEracer601]

Hmm never heard of tracks doing that, they are catching on somewhat I suppose. lol Intake valve timing events will still effect the overall dynamic cranking compression, because some of the air is going to be pushed back up the intake port if the IVC event is late enough. ( Intake valve is still open slightly when piston has changed direction and is actually coming up) I would test this your self and see how much of a difference it truly makes with exhaust rocker on and off. If it's a solid cam, try it both ways with normal lash settings, then tighten the Intake lash by .004" take readings, then maybe another .004" tighter.and try it both ways again. THIS IS FOR TESTING ONLY...The first .004 would be fine the second not so fine:eek: Please do let me know what you find because I am curious myself. I believe the readings will be close to one another with the exh. valve working or not, and that Intake valve timing will still have an effect. Wish Bill H. was still with us, he has probably already been down this road. Maybe TBRE will chime in.

Sorry its hydraulic!