Rigas Chaloftis RG740cc
A 740cc RG engine that has actually run!
Rigas resides in Greece, where he is a teacher. He is also one of the most hardcore RG and 2T fans you can imagine.
His mega-project involved taking an RG out to 740cc. Here are his notes:
" 66X54mm (bore and stroke) makes a 740cc engine.
Pistons are from Yamaha DT200 and the conrods are aftermarket (same long as the stock ones but their upper end is for the 16mm piston pin of the DT200 piston).
Uppercrankcase is bore out to 70mm so to accept the cylinder’s bigger sleeve.
So the cylinders are resleeved to 66mm bore and 70mm external diameter.
Upper gaskets are made of copper 2mm thick bored to 66mm and the lower gaskets are stock bored out to 70mm.
Cranks are from the good old RG250 Gamma modified on lathe to the 500’s dimensions keeping their 54mm stroke.
The RV’s are Franco’s 116mm carbon as well as the inner seats. The outer seats are Mark Drysdale’s ones bored 38mm for the Mikuni 38TMX carburators.
The flywheel is from the Yamaha TZR250 3XV modified. Ignition is from Ignitech programmable.
I think this is all the technical info, let me know if I forget something."