There are a number of ways to repair this. I'd be inclined to bore it out to take a shouldered sleeve with around 3/16" wall on the body and 1/4" at the shoulder. The body should be around 0.001" interference fit, (leave the sleeve bore undersized for final machining in-situ). Once the sleeve has been installed, scotch key it with 2 or 3, 1/8" cap heads, align these to the casting webs. Providing attention to detail is exercised in the initial setup prior to taking the first cut and there are accurate datum points available to clock the bore to, any half decent machine shop should be able to do the repair.
ET: Engine (Twin) Cases Damaged Due To Race and Bearing Modification? Not Sure...
- Thread starter 50BlkShadow
- Start date
I haven’t actually measured, but with 1/4“ at the shoulder…(if you are describing a top hat), I think that would bring the sleeve out into real estate that is frequently visited by the crankpin nut…. or are you suggesting the shoulder is countersunk into the case to clean up the mess?
What is the problem ?,
The bearings have not come out ?,
If you fitted new bearings , They could be ground to fit those small plates.
Do you need to change the bearings ?, Are they worn ?.
The only thing I see wrong is the inner bearings should have staid on the main shafts.
If you needed to fit new bearings, I would fit Lipped outer bearing,
A mod' told in MPH many years ago by Andrew Walker,
Him and his Father were very clever , I think,
Which can't come out, I helped a friend fit these many years ago,
And I have a set ready for my next build.
Just my thoughts.
The bearings have not come out ?,
If you fitted new bearings , They could be ground to fit those small plates.
Do you need to change the bearings ?, Are they worn ?.
The only thing I see wrong is the inner bearings should have staid on the main shafts.
If you needed to fit new bearings, I would fit Lipped outer bearing,
A mod' told in MPH many years ago by Andrew Walker,
Him and his Father were very clever , I think,
Which can't come out, I helped a friend fit these many years ago,
And I have a set ready for my next build.
Just my thoughts.
The idea with the top hat bush is that the flange is in the primary chain side of the hole, not on the flywheel side. If you think about it there is no need to prevent bearings walking inwards, or outwards, with back to back taper rollers.
Very nice idea, that flanged bearing. Very nice.
I would definitely give Glenn Bewley a ring, he does a great job on this. My norvin main bearing housings were a mess but after he did his thing, absolutely no issue. This is a precision job, I would not just trust anybody to do it.
You guys across the pond are very fortunate to have people like Glenn Bewley at your disposal, virtually no one taking on this sort of work over here any more, well not if you want to ride your bike anytime soon.