<< Aluminum dissapates heat much faster than iron. This heat reduction will
allow
you to run a much higher static compression on lower octane gas which in turn
will make more power. >>
All else being equal, aluminum heads will make LESS power than cast iron
because of this heat loss to the coolant. They are not as efficient. Heat
that would otherwise be used to build torque by pushing on the piston is
dissipated into the atmosphere by the cooling system. (Band-aid fixes include
thermally coating the combustion chambers, or increasing compression as
stated in other posts). The main advantages to aluminum are that it's easier
to machine and repair than cast iron, the lighter weight can be a benefit to
handling and in drag racing, and the fact that they usually have a better
port design than production heads... But just slapping on a set of aluminum
heads without making any other changes is no guarantee of increased HP.
Scott
'94 Dakota 318 - 15.24 @ 89
'68 Camaro 355 - 12.02 @ 112
McKennaRacing.com
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:47:53 EDT