318: too much cylinder head?
Flow is not how you should pick a cylinder head. You need to know what you want from the engine, and then get the head csa where it should be. If you have a 2 heads, one flows 280 cfm at .500 and the other flows 300cfm at .500, Most times the higher flowing head will have a larger port/valve. If that's what the engine wants (HP, RPM) then it will make great power. If not, it will be a bag of $hit!
Brian
Brian, i know you did these heads personally so i appreciate your input. If you were doing up a set of edelbrocks for my engine what would you do differently?
First the cam specs, The idea is for a street/strip 318 that has relatively good manners/idle but also just keeps on winding out past 7K on the strip.
Solid grind 242/248 @.050
114 LSA. 113 ICL.
.577"/.587 Lift w/1.6 rockers and .018 lash
(not taking into account loss from pushrod angle)
please note, I am open to criticism on the cam specs. It may sound a bit mild at first but the idea is "more head, not more cam"
I was originally recommended the same cam with a 108LSA by my cam manufacturer.
It is my own idea to run the 114 LSA for the above mentioned engine qualities (Streetable High RPM screamer)
I'm going to run Holley six pack carbs on a factory dual plane high rise manifold and I don't want to run into issues with the front and rear carbs opening off idle due to low idle vacuum.
I'm planning to clean up the runners and plenum a bit in the six pack manifold, but it doesn't look like there's a lot of improvement to be made.
when we dial in the jetting on the dyno, I am keen to try a variety of combinations for open/2 hole spacers 1" thick.
Compression will probably be around 10.5:1 with alloy heads, it has to be safe for 100 degree weather. The 114LSA should help bleed off a little from the dynamic ratio too.
I'll have to open the chambers some to be compatible with the dome pistons or vice versa.
Headers are 1-3/4" with 30" tubes into a 3" collector.
What is the maximum amount of head work you would build for a customer with an engine like this?
Would a full-house set of ported edelbrocks make it run like a "bag of $hit"?
If so what would you change in regards to porting, valve size and/or camshaft compared to the heads in the CC build?