15-04-2024, 11:33 PM
Fitting a 1 5/16" Phoenix crank to an early (1926) mag crankcase is covered on Page 10 of the "Restoring a Top Hat" thread, with photos.
To summarise,
1) drill rear main oil return hole
2) relieve centre camshaft bearing housing to provide sufficient clearance
3) relieve front lip to provide clearance. Crankshaft may have to be relieved as well, so do this before it's balanced.
All the rear main mounting hardware from a 1 5/16" engine is used as well as the rods (obviously!) and the flywheel. 1 5/16" rear mounted starter flywheels are becoming hard to find but a later, 4 speed type can be machined to suit.
Some people have found that the big ends foul the inside of the crankcase, I've done a few of these and not had any problems but it's worth checking.
To summarise,
1) drill rear main oil return hole
2) relieve centre camshaft bearing housing to provide sufficient clearance
3) relieve front lip to provide clearance. Crankshaft may have to be relieved as well, so do this before it's balanced.
All the rear main mounting hardware from a 1 5/16" engine is used as well as the rods (obviously!) and the flywheel. 1 5/16" rear mounted starter flywheels are becoming hard to find but a later, 4 speed type can be machined to suit.
Some people have found that the big ends foul the inside of the crankcase, I've done a few of these and not had any problems but it's worth checking.