The Stovebolt Site Forums The Shop Area Engine Shop 52 Chevy 216 main bearing insert identification ?

I have a 52/53 216 that was converted to insert bearings. All the bearings are stamped with "VR" in a circle. The bearing PNs from front to back are: 2455M, 2434M, 2436M and 2438M. The bearings are .020 undersized. I puting a replacement crank in that is .010 unersized, so I'm trying to identify these bearings to cross reference over to a replace, such as Federal Mogul.

I would not try to cross reference those numbers. I would go to a good automotive parts store such as NAPA, and order the correct size main bearing and rod bearing set for your crankshaft. If the crank is turned .010 under, then the correct bearing will actually be .010 thicker than the stock bearing. How far have the rod journals been ground?

If you are talking about the mains they were always insert then just order 10 over bearings if the rods were converted than you will have to take one to a shop and see if you can match it up.

Pete

The rod bearings for a converted rod should be a standard item, available in standard and undersize. I believe vendors like Kanter carry them.

From the Federal-Mogul master engine bearing catalog:

Main bearing set #648M available in 10, 20, 30,40, and 60 undersize. Consists of one each of bearings numbered 1416SB, 1417SB, 1418CP, and 1419SB. Shim set # FSM 105S is required on 1948-53 engines.

TRW bearing set # MS1175A is the equivalent, in the same available undersizes. It contains bearing numbers MB1175, MB1176, MB1177P, and MB1535. The TRW shim set is #SM 105S. Have fun!

The conversion bearing sets for connecting rods machined for insert bearings are:

Federal-Mogul 1415SB-10
TRW CB503B-10

Undersizes for rods are 20, 30, 40, and 50.

Jerry

Thank you Hotrod Lincoln. That information helps. I have a 1954 Chevy parts book that shows the GM part numbers for both the mains and the rods, but I could never find a cross reference to after market bearings. By the way, originaly weren't the mains also babbitt? Also, to clear up some confusion (I caused), I am replacing the old crank with one I got off Ebay, which ground out as a .010/.010, so I'm shopping for both main and rod bearings. The crank is a GM 3835271 - forged. As for the old crank, the flywheel flange has a back and forth wobble of .009 and a side to side off center wobble of .009. Friends think it was manufactured that way somehow. Lastly I looked for bearings at O'Riely's, Auto Zone and NAPA. the mains were around $250. Don't mind purchasing new-old-stock if it's the right set and a lower price.

Chevy 216's have always had insert main bearings. I think some of the older ones were available as "semi-finished" items that had to be finish-bored after they were installed in the block, but that was back in the mid-1930's, IIRC. Model T, and possibly Model A Ford engines had poured main bearings, but not the Chevy 6's. If you've got the Babbit rods now, you'll need to get them machined for the insert bearings. The proper inside diameter for modified rods is 2.4030"-2.4040". A good automotive machine shop should be able to bore and hone the rods to that size to fit the insert bearings. They're definitely NOT a bolt-in swap! The other choice would be to get a set of .010" undersize reconditioned Babbit rods. Check Ebay- - - -216 Babbit rods are there pretty often. If you choose to do that, IM me about your old rods, I need 'em!

I wish you were closer to Tennessee- - - -I can fix that wobbly flywheel flange in a lathe, but shipping it here would bust the budget!
Jerry

1948-53 216 used the same rods and mains, when you are looking.

Thanks Jerry. A friend of mine machined the forward and back wobble, but the side to side off center cannot be fixed. The pilot hole, the flywheel mounting flange, the bolt holes and the mounting studs are all off center, so I ended up getting a crank that had never been ground. Thats how I ended up with a .010/.010 crank. I see a number of STD, .020, and .030 mains on Ebay, but very few .010. Anyway... the old crank was .020 unnder on the main jouranls an .010 under on the rod journals. My search continues. P.S. I'm still curious about the brand of the mains I posted in my original post.

In researching the correct main bearings, I noticed that there are two rear main bearings (#4) that comes in two different widths. A narrow one (1 3/8") for automatics and a wider one (1 5/8") for standar trannys. I purchased a set of bearings on ebay recently, which have the narrow bearing, but I need the wider one. Can I use the narrow one instead of the wider one. In another post, Truckernix said he used the narrow one in place of the wide one and hasn't had a problem. Just want to make sure it's ok to do.