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Installation of Main bearings and Connecting Rod Bearings

PostPosted: 29 May 2007 1:45
by MLMFLCN
Hello,

I am assembling a 440, and am about 80% done. As I read many manuals and engine builing books, of course, there is sometimes conflicting information. When installing the main and connecting rod bearings, I lubed the receiving side of the main caps (machined portion in the block and "inside" of the main caps) with 50 weight oil, and then gently pressed in the bearings. I did the same with the connecting rod bearings. I came across an old article that stated that the receiving end should be "clean and dry".

Any thoughts on the above? Would lubing the back side of the main bearings and the connecting rods be detrimental to the build? Everything spins nicely, and there are no sticking spots.

Thanks for the help. :thumbsup:

PostPosted: 29 May 2007 9:28
by dave-r
In theory you should put the bearings in dry and then install the caps so you can check clearences.

After all is checked you then put oil or white grease on the bearing surface when installing.

If you are worried about it do it again. But if you have used all good stuff and measured or trust the accuracy of the parts you are using you will be OK just to leave it.

PostPosted: 29 May 2007 9:48
by MLMFLCN
So Dave, when you say bearing surface, that could include the front and back of the bearing? I did set them in dry, and used plastigage to check everything. Once I knew I was okay, then I greased both sides of the bearing and reinstalled.

Thanks again for the great tips.

PostPosted: 29 May 2007 10:04
by dave-r
You just oil the side that touches the crank. There is no point in oiling the other side. It does not move. Or at least it shouldn't! :shock: :lol:

If you have already checked the clearences dry then it does not matter what you oil. Just continue.

PostPosted: 29 May 2007 10:28
by MLMFLCN
Great Dave, thanks. I was getting worried that by oiling the "backside" of the bearings, that it may actually cause the bearings to "spin". With the tabs on the bearings, and proper fit and torque, I think I will be okay. :s022: Thanks again.