Has anyone in recent times experimented with Deep row ball races for the rear main?. I have read all the historical stuff on this subject in the Sbg and the like, but as an engineer,I wonder if there is good reason to restart the debate?. I do like the Idea of locating the shaft at the rear ,and thrust relieving the thrust forces on the bendy shaft. with the new found technology in the Hipped Phoenix shafts,Perhaps those expensive,rumbly rear roller bearings could be improved on?
Any comment from the Racing/Trials fraternity?

Steve

I seem to remember something in the 750 companion about this?

I think from memory the issue with using a deep groove ball at the back was a problem with the crank whip? The standard crank moves in a certain way and I think the article hinted that the difference in location provided by the ball as opposed to roller bearings would cause problems with the way the crank whips?

My apologies if I am talking bo**oks , my memory is not great and I havn't got the book to hand at the moment! It might be that the Pheonix crank behaves differently?

Steve

Also the difference in thermal expansion between the crank and crankcase will overload the bearings if the crank is located axially at both ends.

Rob

Am I right in thinking there are roller races with a "lip" on the outer track? I have seen it suggested, possibly by David Gossling, that this would retain some oil when the vehicle stood and mitigate wear on startup. Seems like a good idea, never tried it!

Regards, Stuart

A lip would make fitting and stripping the rear main very difficult. There would be no chance of reusing it. Keep "as is" is my response. There are other ways to deal with oil problems
Ron

It was my intention to locate the shaft thrust wise only at the rear, the front two bearings could be plain ball races,throw away the front bearing retaining plate or pack it out and put a wiggly washer or "O" ring behind it to allow movement, and retain the front bearings with the driving gear. the front of the shaft can then float and the rear deep groove ball race can handle the clutch /flywheel thrust loads. I am told it is capable of this task. I cannot see that this bearing set up can be any worse than the expectation of the roller race to resist bending loads,which tend to make the rollers toe in and reverse bell mouth the outer races-which I reckon causes most of the wear and rumbliness, quite quickly-any further experiences/ideas?

If the crank was the other way around with the a/c bearings at the flywheel end and the rollers at the front your needs would be addressed?
How come Austins put the thrust taking bearings at the other end of the crank, i.e the front?

Steve

The gears for the cam shaft are at the front so if one anchored the crankshaft at the rear it would seem one might get valve timing issues.
In my engine I put a double thrust at the front to anchor the crank in both directions.
Pat