herm111

When the Majority of the car companies, and other engines builders went to inserts, it was not necessarily better bearings, but it did save bearing builders, and all engine Manufactures millions of dollars. All the shipping back, and forth to the Rod babbitters, all built storage, having to shelf all the different brands, and then different sizes, parts Housing Ect. Rod inserts should NOT be repoured, in any Rod. Inserts in main bearings, (talking a Good Job) is fine, as they do not get the shock that a rod gets. When the inserts are New, say Bronze, the out side, and inside of the insert, is machined, and the rod is bored, or honed to a size to be a almost 100% fit to the Rod. BUT, when you repour, the insert distorts, and will never will be a fit to the rod required to get the fit you need to make the bearing last the rebuild, and it should, and longer. From the time we went into bussiness,( 44 Years ago) we have taken insert rods, and poured them solid. It will make a better bearing any way, and the Babbitt tinned to the rod, does not allow oil to be between the Babbitt, and the rod, which allows a better heat transfer, as OIL is NOT a GOOD CONDUCTOR! If you have a shimmed bearing in a engine, when you have a total of .006 thousandths of shims off each side, your bearing has pretty much run out of it's usefulness, especially on a Oil Pressure Bearing. The reason being, is when say a 2 inch rod hole has .006 thousand shims out, even if the rod can be set to .002 thousandths clearance, top and bottom, the sides still have .006 thousandths clearance on both sides. Yes, you will have low, to No oil pressure, BUT the worst thing, and if the mains have to be taken up like that also, is that the oil that will be lost because of it, the rods pick up the extra oil and through it to the pistions, and you have an oil burner! There are a lot of poured babbitt rods in the the 20's, but being we pour everything, I would say it is about 50, 50 between the two! Now the Bluing of a bearing. Bluing a bearing is all right, if you have alot to Hog out from wear, as it is NOT useful to FINE, or FINISH scrapping. The best way is snug the bearing on the shaft, so you can still turn it with a heavy drag, and it will leave a dark, or rub mark. That is what you take off, and it will only be about say .00020 tenths at a time. DO NOT put your rod on the crank by it's self, as it will most likely change when you put the piston on, and put it in the cylinder. So leave the rings off, and put the pistons on, and in the cylinder. That brings us to Rod alignment, before any rod scrapping, take your rods to some shop that knows how to align rods, for Twist, Bend , and OFF SET, especially if new, as many guys that pour babbitt, don't, and or won't, or don't know how to align rods. Many times when asked if they align rods, the excuse is, Oh the machine bores them straight. The truth is, there is not a machine build, past, or present that will be good enough to put in an engine with out checking alignment of the rod. The Pictures are of, Twist, Bend, and Off Set. Thanks Herm.

I will try to get time to do some pictures, as it takes a while for two fingered typing. thanks Guys, Herm.

<------------------- Ooop's, Sorry Pat, Herm.

We have just Posted some Rebabbitted bearing Pictures if interested. Hit Name, and then my Prolile, and then SHOW ALL ALBUMS, there are about 100 pictures. thanks Herm.

1936 Buick

He said it all, Herm.

Mr. K8096, all engines in the years we are talking about, use babbitt, weather they are poured, in a cast block, a cast one cylinder engine, a connecting rod, direct, or indirect, and also mains solid babbitt inserts, or Brass, bronze, or steel backed, there is NOT a Distinction. Herm.

Don't do it.

All cars, tractors, trucks, and more used poured Babbitt bearings up to, and in to the 1950's, and longer. Herm.

1929 Chrysler Model 65 1929 Chrysler Model 75 1929 to 1930 Chrysler Imp. 80 Herm

Read a Previous post, J.V. Thanks Herm.

I for got to bring up the "method", some use to set cranks. Use it if you want, but what it does among other things, is take the polished finished off the crank, and bearings, some rebuilder tried so hard to put there. One rebuilder left a little in the engines thinking it was going to break them in, and what it done in took the engine out in less then 5 miles, and I mean everything. Do not leave any excess in your motors. Herm.

I don't know where to start here, and it is an old post, But there are a few things I can add here. First of all, our scenario is, if all babbitting, pouring, and or all machine work is done properly. Connecting rod lathes haven't been made, since around 1940, the rod lathes made today, are made to cut brass bushings, and resize rods for modern inserts. The R.P.M's are to fast, and the cutters have to be a totality different design. When you have a new rebuilt rod done on a rod machine, and the crank is ground right, you should not have to do any thing but bolt it in place. This brings us to Plastigage, Plastigage will always work fine, IF you use it right. Instructions say clean all the dirt, and old oil off crank, and bearings. What it does not tell you, don't use it dry, you have to put 2 or 3 drops of oil on the crank, and bearing before the Plastigage, and the the cap. If you don't, a dry piece of Plastigage will not spread out right on a dry surface, as most of the time it smears, and will give you a false reading. Now, Always read the Plastigage on the hardest surface, which is the crankshaft, as the babbitt side can also be a little off. With out the oil, the Plastigage can press into the babbitt. Now, on Scrapping, JV is right about the accuracy of hand Scrapping, as a machine, that mills, or in most cases surface grinds, on say lathe ways, the close as it can come is .003 thousandths, that is not good enough, as most go for .00150, or less in the full length of the bed. On babbitt, scrapping most scrapping in done on old wore babbitt, rather then New machined Babbitt. Now on the oil Blue that can be used, you are better off, if without experience. or with, not to use it at all. The best way is to tighten the cap down, so it drags a little, and the crank will leave Black marks, and that is what you take off. With that said, you should only take off , about .00020 of a thousandths at a time. The scrapper should be laid flat, and the scrapper pulled towards you, and very lightly, and keep them very sharp. This brings us to bearing clearance, which at best can be confusing. In bearing books like Federal Mogel, lets use a 2" crank for this purpose. A bearing book can say .00050 to .00350 thousandths clearance on the shaft. What that means, in even a modern insert motor, you do not have any shim adjustment, so on an engine out in the boonies, you might have to settle for what you can get. Ok, here's the deal, a 2" shaft when hot, will enlarge by 1-1/2, or 2 thousandths, if you gave it 1/2 thousandths, where is the oil clearance going to come from. You need a shaft clearance of .002 Minimum, to 2-1/2 Maximum, so the crank has to strugle to get its self free, and in doing so, where does the extra clearance come from, your right, it is not the crank, it is the softer bearing, and that don't do them any good. The biggest reason for rebabbitt bearing failure is the babbitt not stuck to the brass, or steel shells, in which one, is NOT any harder than the other to pour. When your babbitt job lasts 1000 miles or less, its the bearing rebuilders fault. All I have to do is look at a failed bearing, and easy to tell what happened. About Tinning a bearing, you can have the best job of that, and still not have a good bond, as you only have 40 degrees + or - of temperature to go, or no go. If you don't have two Babbitt Pots that are regulated, it is just about impossable to pour a bearing, and not have it fail, just a matter of fact.