herm111

The original taper shims used back in the day were in 3 motors we rebuilt. The taper shim does not cover the whole insert, so the insert lays on about 1/3 of its surface, and the rest of the insert hangs out in the middle of no where. You have to have 100 percent insert to block concact, to be right! In the three engines, all the inserts had the taper shape of the shim wore in the insert bronze, which made them junk, and the blocks also had wear imprints. So the only way we could fix the mains was to bore the O.D. of the block mains .006, and made new inserts, with a .006 thousandths O.D. You may try to get by now, but you will pay later!

Seeing how lead babbitt is Not Suitable for engine bearings, I won't comment on that. Tin base was used in most all factory bearings. When lead was used, it was used for economy, or durning the war when the goverment had all the tin. Any Grade of babbitt that was ever used in the past can be had today. If it is something that is not used any more, so that it is not kept in stock, the foundry will mix it. The three most common grades used now are 11, 2, and Ford mix, can't think of the number right now. I should say that there still are many guys pouring Lead babbitt, so watch out. Tin base babbit has only 3 metals in it. Tin, Anitmony, and Copper. Tin is used for the over all strength, Anitmony kinda holds every thing together, and Copper gives it it's wearing qualities. Every thing else in the Mix is impurities. Herm.

Your Rods did have .006 thousandths shim on either side, 3 pieces of .002. All bearing books have a low, and a high number to work with. They will say from .000-50 to .003-50, and others, on different types of bearings, but that is because there are many different situations under which a bearing has to be, or can be, fit. Herm. Here are some 1936 Buick 40 series, 233 C.I.D. Rods, and Mains we Rebuilt.

Clearance on bearings should be set an .001 thousandths per inch of crank. You didn't say what size your crank was, but, a two inch crank pin should have .002 thousandths, no matter what engine, and that would be Minimum, or Plus .000-50 thousandths Maximum! Don't forget to oil the Plastigage, and always Mic the crank Pin so you know adjustment would be even plausible. Herm.

the shop I am dealing with has been rebuilding motors sinse the early 30s second generation,,,their position is the multi grade oil,,,after a while,,,works on the bond between the steel and the babbit---I asked the owner how he knows!!!! and he responded with-----------EXPERIENCE-------- "END QUOTE" Mr. Broker-Len, that is a good one. LOL The Translation of that Quote is,( We have trouble with our babbitt falling out of the bearing, so if we blame it on the oil, we don't have to do it over for nothing!) As far as being told that we have been rebuilding motors since the 30's, My Dad used to say,( He knew a Guy who drove a Model T Ford all his life, and he still couldn't drive! ) One of the problems about using different oils is, they all will work. The Question is how well, one compaired against another. New engines, bearings are Narrow compaired to old engines 1900 up to the say to 40's, or 50's. When under pressure, a narrow bearing will get close to a 100 % of pressure all the time, at what ever the pump puts out. Old engines, 1900 up, to 40's and 50's had much longer bearings, if they were splash, they would be better off with thicker oil as say 30wt. as it has more cushion, when running, and will take the heat more, and when the engine is at rest, it will retain more oil in the bearings for the next start up. For the engines 50 on down, we use 30wt. for the same reason. A longer bearing with oil pressure will have less wear in the middle inch of the bearing, and more wear on the out side inch on either end as the oil drops off as there is not the same pressure as in the center, and the oil will not cool the bearing as much.

Rusty, all shell bearings were still lined with babbitt, and we pour all of them, and then they have to be align bored in the block. With rods that were inserted, and if the inserts are not available, or if the rod won't hold an insert, we still pour those kinds of rods solid with babbitt. Herm.

Why does the d*mn spell checker insist on turning babbit into rabbit?"END QUOTE" You are missing a T in Babbitt!

That would do it Robert.

These are out of a Buick Special 40 Series You may want to check the mains also. Do not set the clearance less then .001 per inch of crank. A 2 1/2 inch crank say, would have .002-50 Minumim clearance, and or not over Plus one more .000-50 thousandths. Herm.

I was wondering about where the Becon Rind came from. Is that something one carries in the tool box, or that you would need running shoes for the up coming hog lot Rodeo?

J & M Machine would be my pick also. I have seen all the work, and they would be my pick! Herm.

Mostly with machines, what we can't get with machines, we use 1/8th shank carbide bits special ordered, made to our Spec's. and we do them free hand following a pattern drawn on the bearing. Some very few molds like the picture of a early V-8 ford above has the correct grooves made into the molds. X grooves on most rods done with machines. Thanks, Herm.

Just about all engines from the 20's to the late 40's to early 50's had babbitted inserts on steel or bronze shells, on the mains. Herm.

Any time Mr. Tom! Herm.

Any oil grooves that are Original should always be put back in the same way. Oil grooves that go clear to the backing of the shell, whether they are made of bronze or steel backing is the way it should be. It is done that way to get the deepest grooves, to hold the most oil. Main bearing shells, have to be align bored to match a new ground crank . You just can't cut a shell on a shell machine, and expect it to fit, because it won't. Circle grooves have no place at all in a splash bearing. What happens is if say you have a 2 inch wide bearing, only about a inch in the middle of the bearing gets all the oil it needs, so, if it does not flow to the out side for the last 1/2 inch on either side, the starved crank will heat up more and swell, and open up the bearing to get what it wants, and then the bearing now has more clearance then it needs on the whole bearing. In one of the posts, it said something about a bearing not being a 1/2 circle. I am not sure what was ment by that, but the block insert is always a half circle, and the cap is always a half circle when assembled, whether the half circle in the cap is a full half circle with out shims, or what gone is made up with the Factory shim thickness it had.

Hay Mr. Tom, long time no see. Herm.

Bob, did you find what you want? Herm.

J & M Machine is the best there is out that way. They are in Southborough, Ma. They do all Babbitt, and modern Engines, and have all state of the Art Machines. jandm-machine.com Phone is 508-460-0733 Check out the web. site, and you will see what I mean. Herm.

Very nice clean set up! Herm.

Here are some 1931 Pontiac Mains and Rods I got done today. They came from out East. Herm.

In 1935 they were calling for 140 Wt. Summer, and 90 Wt. in winter. But I think I would leave it 140 if it is in a heated garage, or if you don't drive it in the winter.

I would use 30 Wt. detergent summer, and 20Wt. detergent winter. Change oil every 800 miles.

As the 20-50 may take up extra clearance for sound, the bearing should also be checked. Also the rod could be close enough in clearance, but making a noise from being out of alignment, a common cause of knocking. Herm.

I don't remember, did at any time, did you have the Rods checked for, Twist, Bend, and Off Set? Herm.