Originally Posted by pelico
Was checking out some engines and was just wondering what the difference is between a EFRA & IFMAR Spec engine. Thanks.
The difference in IFMAR and EFRA are the crankshafts. EFRA only allows a 7mm crankshaft bore, and no turbo scoop protruding into the crankshaft. IFMAR has no rules on crankshaft bore, or turbo scoops. IFMAR engines are usually more powerfull.
