The Mopar A4 engine is a 4-cylinder aluminum block racing engine that is based on half of a small block Mopar. This engine uses one small block Mopar V8 cylinder head, valves, rocker arms, valve cover, and header. The drag racing versions of this block have the small block Mopar bell-housing and can be used with a transmission. The Midget versions of the block have the bell-housing machined away to save weight since these racing engines are not used with a transmission.
All A4 Aluminum Blocks have the following features:
4-Bolt Billet Steel Main Caps (All are Cross Bolted)
2.25" Mains (Use Ford 302 Main Bearings)
Ductile Iron Cylinder Sleeves w/ 4.120" Rough Bore
Siamese Bore Casting
These racing engines must be used with a dry sump oiling system, and the gear drive systems shown below.