The bedplate is a structural casting bolted to the
bottom of the cylinder block to retain the
crankshaft. The use of a bedplate further
improves rigidity. Iron inserts, cast into the main
bearing supports of the bedplate, minimise main
bearing clearance changes due to heat
Two hollow dowels align the bedplate with the
Beads of sealant seal the joint between the
bedplate and the cylinder block.
Six counter-balance weights ensure good
vibration levels from the four throw, five bearing
crankshaft. Manufactured in cast iron, the
crankshaft also has undercut and rolled fillets for
The main bearings are aluminum/tin split plain
bearings. An oil groove in the top half of each
bearing transfers oil into the crankshaft for
lubrication of the connecting rod bearings. A
lead/bronze thrust washer is installed each side of
the top half of the center main bearing.
The crankshaft rear oil seal (a lip seal similar to
that used on the AJ16 engine) is a press fit in the
bedplate to cylinder block interface.
SEALANT TRACK ON BEDPLATE
CRANKSHAFT REAR OIL SEAL