Can anyone tell me the difference between IFMAR & EFRA crank specs? I just picked up a V12 Rody 3port on Ebay. It came with no box & no instruction so I have no idea which of these 2 versions I have. Contacting Rody thru the RB site didn't get me anywhere as his reply was to look at the parts sheet for each. This revealed nothing other than the part numbers being different for the crank. He wouldn't freely talk much about the crank & measurements (Understandable).
If you are talking about the crankshaft, EFRA rules : 7mm max hole diameter, 0.5mm max continuous chamfer around the hole (basically means no funky shapes around the hole).
Ifmar allows bigger holes and other tuning stuff.