02-09-2019, 05:33 AM
I dunno how other cars with roller bearings (BSA 10) motorbikes etc fare but almost any clearance in Seven rear mains leads to a degree of rumble esp if spark well advanced. A tight fit bearing reduces the tiny initial clearance and so stays quiet longer.
As a matter of interest what are measured journal sizes on Phoenix cranks? If these are all generously over size at the rear bearing clearances would be very small.
Prior to modern oils with their anti rust properties and wwhen cars were subject to a lot of cold running, many Sevens crept about with grossly retarded sparks. I have a stack of 65 and more year old old bearings with tracks all greyish instead of chrome like shine.
Pre WW2 Len Southward of the notable auto museum ran a business specialising in Sevens. He told my father cars came in with the flywheels rubbing on the case!
With the degree and type of use now seems much less of an issue.
As a matter of interest what are measured journal sizes on Phoenix cranks? If these are all generously over size at the rear bearing clearances would be very small.
Prior to modern oils with their anti rust properties and wwhen cars were subject to a lot of cold running, many Sevens crept about with grossly retarded sparks. I have a stack of 65 and more year old old bearings with tracks all greyish instead of chrome like shine.
Pre WW2 Len Southward of the notable auto museum ran a business specialising in Sevens. He told my father cars came in with the flywheels rubbing on the case!
With the degree and type of use now seems much less of an issue.