From others, I have "heard" the 912 80 HP engine has an installed weight of 165 lbs, not counting the engine mount or firewall accessories (battery, gassolator and fuel pump), but does include fluids and the propeller (Can anyone verify this ????)

As far as the VW, I should point out the VW direct drive can actually be built anywhere between 55-85 HP, and they are all basically the same weight (about 165 lbs without intake, exhaust ect…). The difference in HP ratings are because the displacement range is from 1600-2273 cc, and the compression ratio can be set to run only Avgas, or reduced down to allow 87 Octane Car gas (and anywhere in between). Once you get over 1910 cc’s, you do have to use a Stroker crank and the cost of the long block about doubles (a 1910cc engine will still give you about 65 HP max on Avgas) Also, aluminum cylinders can be used to reduce the engine weight by 10 lbs and a “Fly-wheel” drive version is available too, it weighs about 7 lbs less.

The Honda engine looks really sweet though, I would love to give one a try, but I bet the 178 lbs weight quoted does not include the intake, exhaust and other things that would likely give a total installed weight (with prop) of about 200 lbs, which would be a little less than what a Subaru Ea-81 engine or certainly less than a Corvair engine install would be. Parts would be cheap though, I bet.

As far as my plans for my Kitfox-4, the particular VW engine I am planning on building will be the 2273 cc VW engine, set to run on 91 octane car gas (which we have here locally, made without alcohol) and will produce about 75 HP max or 68 continuous at high speed cruise. With a full electrical system and dual ignition, oil cooler and Ellison injector carb, the total installed weight is estimated to be about 185 lbs, but I might spend the extra $1000 to get the aluminum cylinders, which would drop the weight down to about 175 lbs (not counting the battery, gassolator and fuel pump on the firewall). A light weight (4.4 lbs) ATP ULTRASTART RED battery on the firewall will also help to keep the total engine install weight down.