Check out this air cooled flat-4 VW.
It's essentially an aircooled flat 4 converted to 2 stroke operation.
<notes taken from another site>
"The blower pressurizes the crankcase, which is overfilled with oil, and doesn't burn oil with the fuel, which is methanol. He had 60% of the fuel running thru the Eaton roots blower to cool it, and it got super hot, even idling. The welded together cylinders gave a problem with the lower oil control ring which resulted in the smoking. Rings had to be pinned to prevent rotating and aligning with the ports. Rods are almost 7" length carillos. (look at the pic showing the rods hanging out of the case)
The blower was running at 200%, so ran as high as 26,000 rpm with the engine at 13,000 rpm.
Powerband was insane going from 60 hp to 1000 hp in 50 rpm at first, shearing off the five bolts holding on the T4 flywheel like a laser cut!
The hall effect distributor was hand made, as well as the fuel injection system, as this was before he became an Electromotive dealer.
There are four expansion chambers on the engine, of which two are visible in the vid, and the other two are inside the car out of sight.
They were made with the help of an exhaust system engineer."
http://ecomodder.com/forum/showthread.php/www.mpsys.ca
click on media
then on the last pic
OR
Takes a while to load
http://mpsys.ca/Video/MPS2StrokeBeetle.wmv