Bearing oil holes mis-alignment

[Jimbo01]

While fitting the Silverline main bearings to my Autolinea case I am seeing mis-alignment between the oil hole in the case and the oil groove on the OD of the bearings. The mis-alignment varies but is worst at the #1 bearing (flywheel). At this location it appears less than ¼ of the hole would allow oil to pass into the grove. I have compared the bearings with other bearings I have with the oil groove on the OD (not Silverline) and they appear to be the same. Based on this it appears the issue is the location of the oil holes in the case.

This is the first motor I have built using an AutoLinea case as I do not recall seeing this issue on a Mag case. Is this common on Autolinea cases? What is the best way to take care of this? Do I port the oil holes in the case to match the oil groove in the bearings or modify the bearing (or both)? Are there any other areas that I need to watch out for on the Autolinea case?

Thanks,

[Lee.C]

Funny I was talking about this to someone a while ago.....

There is a thread on here somewhere "Crank-Case Prep 101" or something similar and it mentions/discuses this issue, Some VERY good info in that thread....

Hope this helps 

[Jimbo01]

Thanks for the reply I had read that thread and there is a lot of good info. He mentions to check the hole alignment but I do not see where he offers a fix. The bearing shown in the example by John Maher on the thread has the bearing oil hole that feeds the oil groove designed to be in alignment with the oil hole in the case. In this example opening up the hole in the bearing to match the oil hole in the case would solve the issue. On the bearings with the oil groove on the OD the holes do not line up with the hole in the case (by designed). Before I start grinding on my case to match the case hole to the bearing groove I thought I would reach out to the lounge for suggestions/advise.

[neil68]

One typical solution is to file a notch on the back side of the bearing groove to match the case hole.  The notch should be sloped in order to direct the oil smoothly from the case hole into the bearing groove. I couldn't find a good photo, but this one shows the idea...although I don't think they needed to make such a large notch (it probably only needed to be notched on one side of the groove, in order to increase the overlap from 1/4 to the full diameter of the case hole):

[DWL_Puavo]

While fitting the Silverline main bearings to my Autolinea case I am seeing mis-alignment between the oil hole in the case and the oil groove on the OD of the bearings. The mis-alignment varies but is worst at the #1 bearing (flywheel).  ... Is this common on Autolinea cases? ... Are there any other areas that I need to watch out for on the Autolinea case?

I've read this WAS a problem in first batch of Autolinea alu cases few years ago and has been since corrected. I have the same alu case (CB prepped) with misaligned flywheel bearing oil hole, and I fixed it with just the same bearing modification that has been guided here also. Other than that (and a few machining burr/edge cleanings with dremel or similar when prepping the case), there has been no problems at all and the completed engine has seen a lot of hard use.

[NoBars]

I would probably grind the hole in the case oval with a dremel myself. That way next tome the bearing goes right in.