Other than looking great, is there any advantage to aluminum finned head over stock cast iron head ? If not what is the best cast iron head to use ? thanks Pat
Weight reduction... It's not always one thing that can eliminate 40lbs, but 40 things that can eliminate 1 pound at a time. And... Typically you can run a higher compression ratio with aluminum heads.
Generally speaking the cast iron head makes more power. Won't look as cool or remove the weight but power with a cast head not a problem.
I recalled the older guys back in '53, '54 saying "If you can't afford 'High Compression heads' (finned aluminum) then get 59AB heads..."The hot setup"! Later years learned some, the earlier heads have varied combustion chamber configurations, think there were 3 variations, 59AB being the least desirable. (low compression) As for 'best performance', Barney Navarro did extensive research, (one chapter in his book was dedicated to the flathead head...he named mfrs., and barred no secrets. I'd use Navarro heads, remanufactured now, but pricey.
Compression ratio is pretty much meaningless. What you want is chamber efficiency. It has been proven (JWL's dyno testing) that 45-50 thou clearance over the pistons provides the most squelch efficiency and thus the most hp/torque increase, at the same time giving the best fuel economy. The shape of the combustion chamber will have a small part to play, but not huge. My C7RA-A iron heads on my C59A have been milled to give 45thou clearance, and they give 155lbs compression with WOT, yet run cool. In fact I had to install thermostats to get the engine up to efficient operating temperature.
Hard to beat cast iron. Be sure they are not cracked and have not been shaved too many times. Pretty much bullet proof and they don't corrode like aluminum.
I like the look of the finned heads on my T modified. Unless you are racing and know how to do the super tune on the motor I bet you would never detect the differents between aluminum and cast iron.
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