Originally posted by PHiZ
specifically the integrated block-guard was what I thought was neat.
it's called a supported sleeve system.
I got to thinking though... and let's assume that (any) sleeves are made out of a denser material (seems likely) than the rest of the motor... and they do not have the benefit of homogenous contact, like a solid motor... I wonder how this affects heat transfer and dissapation...
-PHiZ
all Hondas are like this. B motors use iron sleeves with an aluminum surround, while H series motors use FRM with an aluminum surround.
this is due to metal to metal heat transfer isnt THAT important when there's a water jacket surrounding the cylinders for cooling purposes. the only way this would be a problem would be if iron distorted more than aluminum under heat stress... if so, the iron sleeves would expand and cause the aluminum block to possibly fracture.
but since iron doesnt distort more than aluminum, this is not a problem.