Back in my bike racing days, there was a class in the UK for what were once junk air-cooled singles, very free regulations. One common tweak was to convert to water cooled by just brazing a box around the cylinder and head, adding some lines and a small radiator. Some would even add a pump, although many just relied on simple convection flow.

Anyone tried such a thing on a Type 4? Even just doing the heads, as in the 917 (or was it the 956?) would allow you to substantially raise the compression ratio. Might significantly reduce the chances of things like dropped valve seats, as well.

I think Porsche originally developed its water cooled heads for their aborted six cylinder Indy car engine. They then modified this engine and installed in the existing 936 for that car's final Lemans win. From there it went into the then new 956 and later 962 models for the FIA sports car series. I think the 962's that raced in the IMSA series were restricted to the older air-cooled heads.

Mike

The eighties Vanagon has a water cooled head. Later vw went to a full water cooled engine...They call it the wasserboxer.
http://www.justveedubs.com/water-cooled-va...agon-engine.htm has a pretty good overview of the systems...
Maybe you could barrow some of that technology?
I have too many air cooled projects to go any further with this one!!!