Odd noise

[Tony Press]

The ball bearing at the rear sounds a great idea. It would be nice to compare the dynamic ratings of 1920's ball and roller bearings as fitted originaly to similar of today. Bearing improvements in desiign and materials must be considerable. There will be thrust at the front from the single helical timing gears but I don't khow how that compares to magnified foot pressure on the clutch

[/quote]
I had forgotten about the timing gear thrust

The shaft fit will be critical if the thrust is to be taken on a rear ball bearing- possibly a tighter than normal shaft fit which would need a ball bearing with increased internal clearance - SKF C3. Trying to effectively trap the bearing inner ring between the flywheel and crank shoulder as well as getting the proper fit on the taper would be very difficult. 

The metallurgy improvements are significant - my initial discussion referred to the 1950's bearing specifications but checking current SKF bearing specifications-

Ball Bearing SKF RMS 10 is now quoted as dynamic capacity 7,464 lbs - approaching the 1950's Roller Bearing SKF CRM 10 at 8,000 lbs.  

New genuine inch series ball and roller bearings are hard to find now, so we source original old stock SKF or RHP bearings to avoid the too easily fallen into trap of buying new Chinese copies (which regularly mimic SKF in packaging and marking) made from inferior materials. 

My initial comment about relative bearing capacities was to illustrate the likely original design reasons for the Austin Seven engine bearing selection.

Can't help thinking this discussion should be under a different heading but that is often the way with the Friends Forum

Cheers, Tony.