Just something I noticed while noodling around in the sandbox trying to make an uber-Flatplane V8. I managed 1850 with aluminum heads and changing to Cast Iron boosts me to 1859… Is this supposed to happen?
Yup! Whilst slightly lighter, Aluminium heads lose a tiny bit more heat, thus make a tiny bit less power. Its such a small effect that you only really notice it when you’re making 1000hp+ though.
That is the most interesting thing I have learned in a very long time. Thank you!
yeah its very interesting!
although Running Cast iron bits would negate the extra power by simply being heavier so it wouldn’t work out to extra performance at the 0-100kmh tests id think
Yeah, you’d have to be making a truly spectacular amount of power from a small engine for the power gain to be worth the weight gain
I could be wrong, but I was under the impression that aluminum heads were less prone to detonation, thus allowing higher compression ratios and more power compared to iron. Also a bit off topic, but I noticed using iron blocks with aluminum heads causes MTTF to plummet versus all iron or all aluminium motors. I know they theoretically have different rates of expansion which can cause head gasket issues, for example, but I find this unnecessarily exaggerated. It literally cuts engine life almost in half.
The MTTF penalty should apply quite hard for approx pre 1970s engines, but its not quite balanced the way we want yet.