I noticed that most of the vendors sell re-babbited bearing caps . The babbit in my block looks decent , but there are no shims left in the caps . If I got the re-babbited caps how to you do the alignment of the caps ? do they still have to be line bored ? I also have excessive end play and am wondering if this can me taken up with the rear cap
Replacing the rear main cap will take care of the end play issue but the thrust surface will be less as the thrust surface in the block will remain the same. I don't know if it is right or not but when I did what you are thinking about I did not line bore. I determined that the crank was laying flat on the bearing surfaces in the block and just used shims to get the correct clearance with the caps. My main journals were standard with no appreciable tapering. To address the end play I built up the front face of the cap on the center main to act as a thrust surface thinking that might make up for the reduced thrust surface. So far so good but I guess only time and miles will tell. I am not suggesting that you do what I did unless those who are much more knowledgeable in these matters suggest that it is a viable option.
As far as taking up excessive end play at the rear cap is concerned, one way that's been around for many years is to elongate the holes in the cap so you move the cap up to lessen the clearance.
You can install shims in the bolt holes to help hold the cap up in place if you want.
Its a simple fix that will last a long time.
This method has been in the vintage Ford from time to time over the years and is probably the most simple way to do it if the babbit in the cap is still good.
There weren't any thrust surface in the block originally, so a rebabbitted rear cap should fix the axial play issue.
If the rear cap isn't so worn maybe soldering on some babbitt on the thrust surface would work? I've done it and checked so the play to the crankshaft journal is Ok.
John Regan has an article about it written by Ken Foster in his document library at www.funprojects.com , I did it in a cruder way with a file and no lathe, but it's still working (but maybe not for as long )
But first check carefully with a steel ruler so the mid main isn't worn upwards in the block - they tends to wear in the block while front and back wears more in the cap.
I didn't have the funds to do a babbitt job on the block so I used the re-babbitted caps many years ago. I too had to use a file to fit the end thrust. I did have to build up the thrust on the No 3 cap about a year ago but knock on wood has been good so far. While I don't do in the 1000's of miles a year, the car does get driven maybe like 500-600 miles a year. Your experience may very but sometimes you need to look at how you will be using the car and what your pocket book will allow.
(Message edited by redmodelt on November 07, 2015)
personally i built the rear cap up with solder to reduce end play and it seems to be working well.
Wow Mike, I could have been the one to write this post. An engine I am just tearing down has every fault as your. The mains mic out as std but the thrust bearing is completely worn out. My crank mics out at std. I have decided to replace the three main caps with std caps and adjust caps with shims. If all was std before, than all will still be std after.
Kep, Solder? How did you do that? Did you drill shallow holes in the cap to anchor the solder?
Same way I did only I used babbitt. Clean the old babbitt very good where you are going to add new. A light touch with a soft flame on the torch, just enough heat to melt the babbitt you are using and melt the surface of the old babbitt and build it up. You do not want so much heat that it melts the babbitt away from the cap. Generally it only needs a thin coat on both ends to get it back to where it needs to be. The more you put on the more you have to take off.