Quote:
Originally Posted by BIGJOE
I will give you an example. The best ported 351 Windsor castings will be 60 to 70 HP LESS than an out of the box AFR 165 Alumuinum CNC ported head. Unless you just want to do the work for fun--- dont waste your time, The flow numbers the other guys are talking about are NOT the only thing that makes horsepower. They just dont know that.
JOE SHERMAN RACING ENGINES
|
Joe, beyond flow numbers - which are admitedly one part of the power equation - what are some of the other head design characteristics that add hp? I would assume combustion chamber design, spark plug location, and the head material. What else?
Regarding head material, I saw an article on a 351W build up years ago where they dynoed identical castings on the engine, except one set was cast iron and one pair was aluminum. The aluminum heads made 20-30 more hp. Popular wisdom is that aluminum heads also allow one to run a higher compression ratio. Has that been your experience as well?
In my case, I'm building a '69 351W to replace the tired 302 in an '82 F250 pickup - Comp Cams XE250, Stealth manifold, 600cfm carb. It has been kind of fun porting the heads, and I just can't rationalize spending $1,000 above what it's costing to rework the D0OE heads I've got for a pair of AFRs. If I was building a hot rod, no doubt about it. But not for my lumber hauler.
Thanks.
