Main bearings.

I am looking for a set of main bearings for my `31 Commander 250 CID. They fit `29 to `31. Want .10 over or? Part numbers 171878,171879, 171880 and 171881. Art in Cal.

Probably unobtanium. I wouldn't mind having two sets myself for my 1937 engines, though I need different part numbers. Have you found any standard size bearing shells?

Several options exist, so I'm told. See the article by Ford Stoecker from Antique Studebaker Review, May/June 2000, page 16-17. He discusses what he did to get bearings from other makes that can be machined to fit, sort of. I recently spoke to Dave Thibeault about main bearings for the 250 cu in straight 8. He can take the old bearing shells, have them re-babbited and bored. I think what one really wants is to put the raw re-babbited bearings in the block and line-bore. Dave's in Maynard, Mass., full-time Studebaker parts dealer. He has new cam bearings for these engines, as well. I also saw recently a post somewhere else on this AACA site about shimming the bearings from the back side. Looks like a possible way to go. See http://deckwartaperedshims.com/index.php.

I'm going to have to face this problem pretty soon myself, though I haven't pulled the engines apart yet.

Thanks for the info. Have talked to you before. My `31 appears to be OK at this time but was just planning ahead. I was about to call Dave so I will save the call. I do have some extra rods that work. Trying to get the old gal running again after getting it from a deceased member who owned it for 35 years. Found #8 rod gone so I thought I would ask. As far as shells I have two extra blocks with some main caps and rods. Guess I will hold onto them for any future needs. Thanks again for the info. Art. in Cal.

If I am reading the parts catalog correctly, rods up to 1934 were babbited, 1935 and up had inserts, available in standard, .005", .010", and .020" undersize. This is why I chose a 1937 block for my Indy car project, rather than an earlier block, though they look almost identical externally (fuel pump location was moved back to front). I think, but am not positive, that the newer rods with inserts will fit older engines and pistons. But, it wouldn't be that bad to get old rods rebabbited and bored to size. It's the mains that are tough.

Thanks for the info. Art.

Gary is correct regarding the rods. Mains were poured on the early engines like yours. In order to use inserts as per Ford Stoecker's article the block has to be machined to accept the bearings of choice. Unfortunately, I have been told, that the supply of virtually all of the bearings that Ford mentioned in his article are themselves no longer available. As an aside, the engine was redesigned several times between 1929 and 1942. The first redesign was for 1935 with the advent or insert bearings. Then again in 1936-37 there was a change in the crank shaft which was significant enough that those two years have a unique part number. The 1936-37 cranks also have an annoying tendency to develop cracks. I have been told and my own inspection, indicates that about 50% of the 36 and 37 cranks have cracks in them. I don't know if later, more plentiful cranks from 1938-1942 engines can be used in the 36-37 engines. Does anyone know for sure? In 1938 the water pump was moved to the front of the engine and a water distribution tube was installed for better cooling.

Bill: My 1929-40 parts catalog for all 8's shows that the insert bearings were used on the mains going back to the 1929 FC Dictator and FD Commander, as well as on Art's 1931 Model 70 Commander and later cars. It was the rods that were originally babbitted and, as you say, were change to insert types in 1935. But, now you have me scared about cranks. Where do I look for the cracks in my 1937 engines? Do they need to be Magnafluxed to find them?

Has anyone used Hart's Machine Service (http://www.hartsmachineservice.com/) in Ohio for babbitt jobs or a similar shop?

Ah, and the debate goes on. In my engine and my two spare blocks the main bearings are inserts. One block is `31 and the other is `32. Thanks again for all of the info. Art.

Art: Here is the drawing for the 180793 rod used in all of the 250 cu in engines from 1935 and later. Compare the dimensions shown to your rods. If your babitted rods are basically the same dimensions, maybe you could swap in a set of rods from a later engine. I'm hopeful that might work because the piston pins are the same 1929-42. I wonder if anyone has done this swap? Standard size rod bearing inserts seem to be available. I don't have a drawing for the earlier rods, but the Museum may.

Appreciate the info. In checking my book I note that between `29 and`34 there were 9 different rods used for the 8 cyl. engines with poured rods. I will measure my rod and see if it is the same. Thanks, Art.

Gary,

I wonder if it wasn't the cam bearings that were poured and line bored on the earlier engines, can you check? Don't panic yet you do have a 50/50 chance of having a good crank. It does seem that hard use was a contributing factor to their failure. I have four 36-37 cranks and two of them are cracked between the last main and the flywheel flange. Jerry Kurtz first told me about the issue some years ago and sure enough he was right! Thanks to a good number of friends I now have a useable crank but I wasn't sure what I was going to do for a while.

I hope that you find my odyssey somewhat interesting. It began about five years ago when I tore down the original engine from my 1937 President coupe. Finding the block cracked and the crank turned .020/.030 I decided to use a backup engine that I had lugged back from Chico Ca. in 1992. The second engine looked good and in fact the block was fine but magnafluxing the crank showed it to be cracked. The reason that I was shying away from using the original crank was that I had been unable to find suitable bearings for that crank, but I did have a set of .010 rod bearings. I felt lucky to have the .010s, since all bearings are virtually unobtainable, so I was determined to use them. So now I start looking for a useable crank. My search led me to a nice gentleman in northern California who had extra parts for his 1936 which he would talk about. So on our way to the Reno Air Races we stopped by to see what he had. he had the crank that I thought that I needed, but to get the crank I had to buy the whole engine. Throwing caution to the wind I bought engine number three and took the crank with me in the trunk of the car and made arrangement to have the block delivered. After returning home I had the crank magnafluxed and found it to was cracked also. Now what was I going to do, I had two cracked cranks one cracked block and an undersized crank with no useable bearings.

Now my luck starts to change, thanks to Terry Frye from Wisconsin who had been parting out a 36 President. I called but he said about everything was gone, except the crank. BINGO! Keeping my fingers crossed we made a deal on the crank, but how was I going to get it to Seattle from Wisconsin. Luckily both Ken Voigt and Terry were both going to be in South Bend for the swap meet. Ken had a friend from Helena Montana who was scheduled to visit him at his home in SD. I have a friend, Orvil Gilbertson, from Seattle whose in-laws live in Helena and who makes periodic trips there during the year. So Terry took the crank to SB where Ken picked it up and transported it to SD where his friend hauled it to Helena and left it on the front porch of Orvil's in-laws, where Orvil picked it up and took it the rest of the way into Seattle. Thankfully the crank was not cracked or this epic could have turned in to a tragedy! Thanks to all who made the all happen. I learned things about these engines that I probably would have been happier living my whole life without knowing, people say that it builds character. I don't know about that but I think that it makes for a good story.

I have a 1931 8 cylinder engine minus head for sale and a complete 1939 President engine also.

I can not ship these so pickup only in Joliet IL.

I sold some undersize rod bearing to Ford Stoecker years ago but have not heard from him for a long time.

Rumor is that the 1935 President engine that Ford rebuilt and was featured in the above article in post#2 , was having problems. Ford are you on this forum and can give us an update?

As more and more of the "250" engines and their cars are being restored,maybe Dave Thibeault can look into having bearing insert made.

King Bearing Co.is known to make short runs of oddball bearings.

Robert Kapteyn

studebaker@mac.com

Put "Studebaker" in the subject line otherwise it goes straight to "trash"

Did anyone ever start a spread sheet listing the part numbers of rod and main bearings of these engines with the part numbers

of after market manufacturers such as McQuay , Monmouth, etc?

If not already started will anyone assist me in making one by contributing what you already know.

I have boxes full of main and rod bearings that have not been sorted or identified.

Robert Kapteyn

I'll apologize for highjacking Art's thread a bit, as we digress into talking about the rest of the bearings in these engines. For the cam bearings, my parts catalog shows a set of 6 bearings used on each engine. There is one part number set for early engines into 1931, e.g. for Model 70 Commanders having engine numbers before C-7737 and also from C-7793 to C-8729. Then there is a second set for 1930 Model 61 and Model 70, after engines A-9150 (Dictator) and from C-7737 to C-7793 and after C-8700. The third set covers all 250 cu in engines from 1932 on.

Described in the book in this way, I have to assume that they were all machined bronze sleeves to be pressed into the block. I haven't actually seen a set. The front and rear cam journals were 1" wide, the middle four journals are 5/8" wide. I.d.'s range from 1.748 to 1.935". The bores in the block for the cam bearings range from 1.880" to 2.066" at the front end, so the bearing sleeve wall thickness is about 1/16". I have copies of the full-size machining drawing for the 1936-37 block, as well as the drawings for the cam, pistons, wrist pins, and miscellaneous other parts. The block drawing (187136 for 1936-37) is about as big as a bed sheet. Later blocks moved the water pump to the front but kept the same cam bearings and many other parts.

I did see a number of notes on the block drawing for drilling and reaming holes "for service only". I think some of these are the 5/16 holes for a dowel pin that goes through the crankshaft main bearings. The issue with having some company like King make reproduction main bearings is that there are a front, center, rear, and six intermediate bearings multiplied by different parts for 3 groups of years multiplied by the various size possibilities (standard, .005 under, .010 under, .015 under) - that's a lot of bearings! Does anyone have a crank drawing or bearing drawings?

I appreciate all of the input. Keep em coming. Don`t worry about any hijacking. I have been doing Studes for 46 years and love all of the knowledge I can get. A question for Buffalowed. Where did the cracks show up? I have my pan off and would like to check the crank if I don`t have to pull it. Art.

Sorry about delay in responding but I did respond to Gary's inquiry. Found my crank's cracks in the aft part, between the rear main and the flange to which the flywheel attaches. There may be other areas also but this is where I found mine.-Bill

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!

An interesting thread on oil and babbitt in general discussions

http://forums.aaca.org/f169/motor-oil-cars-30s-373394.html

Robert Kapteyn