> 
>
> 
>I've also been thinking about the benifits of plating the outside of the 
>jugs with either zinc or copper.  
> The trick is to prevent the jugs from rusting and 
>enhance thier thermal conductivity at the same time.  
>
>There is more to the story. I am currently having a 2800cc type4 off road
engine built. I was so impressed with the boxer heads afrer they were coated
I am having the heads coated on the race motor. I am doing the combustion
chambers(they are masking where the cylinders seal)the valves, and the
exhaust ports(with the  hard shiny black ceramic. The ceramic they put on
the pistons and combustion chambers is silver and is kind of soft). The
piston tops will be coated and there is a ceramic coat that will be applied
the the outside of the cylinders that is supposed th enhance the heat
shedding ability of cast iron. I don't know how well this works but I was
thinking the same as you that if the cylinder didn't rust it would cool
better.The coater told me a story about a guy with a Harley. Apparently the
rear cylinder of Harleys have a tendency to overheat due to the heat flowing
back from the front cylinder. He said that this is a problem on hot days. He
did the cylinders on a guys scooter and after it was all done this guy took
the bike for a ride on a hot day with a bunch of other riders. All of the
other bikes had to stop to cool but his stayed cool. Kind of sounds like the
Mrs. Fields cookie story Huh? Any Harley riders out there? Anyway, this
story comes from a pretty good source ( I think). One other thing I had
coated was the exhaust header that goes under the head. I figure that any
heat radiation from the pipe that close the the fins of the head would have
to transfer  unwanted heat to the head. This coating is supposed to keep the
pipe cooler and the heat stays in the exhaust gasses and blow out the pipe .
As extra insurance I am going to wrap the pipe in header wrap. I hope to
pick up the type4 heads today from the coaters. I think I'll call him right
now and see if they are done.
Todd Francis