Kevin in Atlanta

I need to groove the bearing that feeds the 2 - 6 and I believe from what I've read here it needs to be 6 mm wide and 50 thousands deep and 270 degrees long.

This is what it should look like done right:


Any suggestion for who can do this?

Thanks.

Chris Lockhart

Kevin, have you talked to your local engine machinist? That's where I'd start.

Kevin in Atlanta

I am going to do that - just had that thought, too.

Great minds think alike.

BC had his grooved on a lathe - but I think current the school of thought is to use a CNC to get it done, if possible.

Chris Lockhart

Lol! Yea I agree, I think CNC is the way to go. Good luck with it.

GregBBRD

I do mine on my lathe, in a custom fixture to hold them, with a 4 jaw chuck, so I can spin the two bearings off center.

The soft part of the bearing "smears" and "folds" over the edges of the cut, requiring a bunch of hand work.

I dread doing them, every time I have to make a pair....lots of work....and I've got a little box of rejects. Expensive rejects!

Kevin in Atlanta

Yeah, those are not cheap. Two possible volunteers to groove the shells. I'll have my engine builder look at them on Monday. If he passes Peter de Jong in SC thinks he has a mill at work the can do the job.

skpyle

I am assuming this modification is to improve the oiling to the bearings on connecting rods 2 and 6 under high load conditions?

jpitman2

270 degrees on a half shell? Or do you do it to the pair of shells?
jp 83 Euro S AT 57k

Kevin in Atlanta

In conjunction with additional cross drilling I had done to the crank, yes.

Strosek Ultra

Picture of the additional cross drilling, please.
Åke

Kevin in Atlanta

* Post #17*Can this crank shaft be saved*

Catorce

If there is enough demand for something like this, I could do it on the 5 axis and it would be done right the first time. Maybe Greg wants to donate a correct one for me to look at???