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Extreme Veteran
Posts: 446
Location: Beaumont TX | I have a 1955 259 V8 and my crank shaft was ground down too much.
Has anyone heard of getting the next small size of main bearings, .030 for example, and boring it out so it would fit like a .024 bearing?
I'm trying to figure out how to tighten up the my main bearings without pulling the engine. I think I can make the tool to use to change out the upper main bearings with the crank in the car and replace the bearings.
Thanks,
sam |
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Expert 5K+
Posts: 9692
Location: So. Cal | No. Bad idea. Bearings are built with different layers that are required for long life & good wear. If you bore even .002" off, it will ruin it. A better idea is to get .02" bearings and add .001" to it by plating it with tin or whatever was the last layer on it. But don't go over .001" or .0015". If you need more than this, regrind your crank. But since your problem doesn't seem to be that acute, it may be best to live with it and run more oil through it with a higher volume pump. |
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Extreme Veteran
Posts: 446
Location: Beaumont TX | Thanks a lot Nathan. I didn't know this. Just thought it was like the babbit of the old days when they were poured. I looked at my pictures that I'm about to post for another thread and you can see the thin layer you are talking about. Here's a picture. Look at the edge of the bearing and you can clearly see the layer you are talking about. I didn't see this when looking at the actual bearing. It shows up a lot more on the picture.
Edited by samstrader 2020-10-30 4:20 AM
(Rear Main Seal.jpg)
Attachments ---------------- Rear Main Seal.jpg (247KB - 156 downloads)
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Expert
Posts: 3780
Location: NorCal | Some bearings like a basic bi-metal might be suitable for boring a little oversized but the multi-layer type can't. You'd want a .020" bearing to be able to bore it for a .024" journal.
(Bearing Layers.jpg)
Attachments ---------------- Bearing Layers.jpg (31KB - 150 downloads)
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Extreme Veteran
Posts: 446
Location: Beaumont TX | Thanks 57Chizler... I had no idea bearings were made like this now. I think my rear main bearing is the tri metal but not sure what the rest are. My rod bearings are probably the tri metal with cosmetic tin flash. Here are two pictures that show sort of what your diagram shows.
(Rear Main Seal.jpg)
(Rod.jpg)
Attachments ---------------- Rear Main Seal.jpg (247KB - 153 downloads) Rod.jpg (239KB - 149 downloads)
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