Darren is a firm believer in the 911 cooling, talk to him. I'll bet the nay-sayers have no personal experience with it, so in my mind their comments are meaningless.

A small upgrade for the stock fan is to turn it a little faster, kind of like a reverse power pulley. Get a bottom pulley from the last of the 36hp engines, it's about 12% bigger. The belt needed is 36.6" long. Before you use it, MIG-weld the center hub to the pulley, or it will come apart like my last one did. I just don't understand why the 36hp pulley can't take 7000 rpm??? ;-)

Bruce Tweddle

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I have a much simpler (and less expensive) cooling set up in my car. I'm running a mild 2016, 7:1 c/r, 35 degress total advance, 94 octane, 4.37 r&p, .89 4th and a 25.5" rear tire. When this motor was in my convertible, in addition to the dog house cooler, I ran a Messa 96 plate cooler with thermostat-activated 10" fan. I needed this set-up because convertibles run hotter than sedans, especially with the roof down. I also towed my small boat with it.

When I placed this motor in my '67, I got rid of the Messa cooler and the extra lines, feeling that they were not needed. It seemed to me that the fan needed a steady stream of cool, near-ambient air. I therefore cut out a 2" hole in the front breast plate, to the right of the starter. I have a 2" hose aimed at the fan, running through the hole, down towrds the right lower shock tower. I have a 4" scoop clamped to the shock tower (on the inside next to the bottom of the shock). I then run an adaptor from the 4" scoop down to the 2" hose.

I have found this set-up to be extremely effective. On a recent 10 hour (return) trip to the Michigan Bug Out, at 65 mph on the highway in 100 degree heat with a fully-loaded car, the engine ran cool. Now that it is Fall, I have blocked the scoop so that the engine doesn't run too cool.

While I recognize that bigger, higher compression ratio motors produce more waste heat, and may require additional coolers, cooling the oil is an after-the-fact solution. Providing cool air to the fan keeps the head temps. reasonable, and the oil never gets excessively hot to begin with. The drawback to my system, however, is that it relies on the car's moving to bring air in. It will therefore not help with cars that tend to heat-up in traffic.

Aside from ensuring that the combination works (parts, assembly, jetting, timing, c/r, etc.), keeping an engine cool is all in the details. I bare-metal all the original VW tin, and paint it with two thin coats of semi-gloss black. I also paint the cylinders and push rod tubes with a thin coat of diluted flat black to help with cooling. No gaps in the tin, mounting the filter in the fender in a stream of cool air, etc. It all adds up.

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