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Old 04-12-2006, 08:46 PM
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Originally Posted by Elevinpointsixtoone
Hello fellow gearheads, after searching the depths of the knowledge base I have gathered enough info to answer many questions without have to So now I need to as a question; can someone point me to a basic guide for choosing a port cc volume or a port CFM aim point based on my specifics?
I'll list my hardware just in case someone might have an eduacated reccomendation but a resource for furhter research would be much appreciated!
Goal: 500 streetable HP
Chevy 383, Hooker 2112 super comps, 3" exhaust, tunnel RAM, dual 500 CFM Eddelbrocks, forged flatops, 11.6:1 CR...balanced, blueprinted, full floaters blah, blah, blah....57 Chevy, Tremec KO, 3.73 gears, 4-link etc.
Yes and the missing goods:
L-98 GM Aluminum vett heads 1.94/1.50, 163 CC intakes that flow around 196 CFM at .500 lift..and those wonderful 58 cc chambers that give me that CR with flatops.
Bump stick to be announced....currently .498 lift, forgotten duration and definately lacking.
Specifcially, I will look at installing the 2.00 intake/1.56 or 1.60 exhaust valves (you tell me) and then having them ported to what CC/CFM?
Right now too much low end and mid and not enough top end. Obviously the cam and heads are the cause. But I don't want to kill intake port velocity for the sake of huge CFM at .550 (intended cam range) lift. It still needs to get out of the hole and cruise down the highway. I'm guessing with all the cubes and high CR that this combo will absorb some decent port volume.
For the sake of argument, lets not get off on other head casting suggestions....I have a few bucks into the heads and want to keep the CR/flatop combo.

Your cylinder head selection is illogical. L-98 aluminum heads are poor flowing heads. They can be made to be a fair performer, but are more suited to low end torque production.

Don't lie to yourself and think that you can on a budget, get them to produce race car like power. I know that you probably like the look of them, but by the time you actually pay someone to port them EFFECTIVELY. You could have went out and purchased a brand new set of aluminum heads from Brodix or Dart or RHS, and saved yourself a bunch of time, and also the disappointment that your goals aren't met.

Large cubic inch small blocks like 383's or 400's are under-valved no matter what you do, so why further hinder it by putting a restrictive, albeit aluminum head on there?

You want a daily driver and you are shooting for an 11.6:1 compression ratio? You should re-think that.

There are tons of good, new, affordable heads out there, why not use them?
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