fastj22 wrote:The Aerovee is based on the type 1 case with bigger jugs to bring it up to 2180CC. Some builders/hotrodders will put in a different crank (stroker) to increase the displacement up to 2400CC, but this also increases compression ratio. Not something we generally want in an aircraft engine.
Just a clarification:
The Aerovee (and other 2180 CC Type 1) is stroked, too (that's why the case has to be modified a bit inside for "clearancing"). As far as I know, the largest from-the-VW-factory stock Type 1 stroke is 69mm, and the largest "normal" Type 1 engine "build up" that retains that stroke would be a 1915cc engine (with a 94mm bore). The Aerovee and other 2180cc engines have a 82mm stroke and a 92mm bore. The 2300cc engines have the same stroke as the 2180cc Aerovee, but have the larger 94mm bore jugs.
Any of these engines can be found with various compression ratios depending on shims that are used.
Type 4 engines: On paper they have several favorable attributes, but suitable cases and parts are relatively hard to find and expensive. The Type 1s do most things very well if their limits are respected, and the parts can be had at reasonable prices.
Mark W.