Shims under main cap and Rod caps ?

Add shims until the Plastigage shows .003" clearance.

The shims allow for adjusting the clearance without needing new bearing inserts as the original soft babbit lined inserts wore fairly rapidly.

Modern inserts can be made to not need the shims.

Gerald J.

Gerald J. wrote:

Add shims until the Plastigage shows .003" clearance.

Actually, you should REMOVE shims until the Plastigage shows ~.003 clearance.

You should always start with the full shim pack and remove shims if necessary. You may also have to file the end of the bearings if you have to remove shims. Starting with too few shims can (over) crush the bearing mating surfaces.

Read the service manual. It details the process, step by step.

When doing an overhaul I have the engine line bored and rods machined so that they do not require shims, like other engines. Easier to assemble, more accurate.

Allis B, IB, Low B, G, D10, JD M, 8KCAB, C152

Here is a sheet showing the clearances.

I have always used as close to .002 I could get with plastigage. Just remember that you need to have the exact thickness of shim under both sides. The rods and mains were bored with .010 shims under the bolts which when done let the caps shallow from half round. That was done so shims could be removed in the back yard or barn to bring the clearances back into spec. I had the rods bored to eliminate the shims on my pulling C. When assembled on a fresh ground crankshaft the plastigage showed a clearance of .0015.

Edited by Dick L - 05 Sep 2016 at 4:18pm

Okay guys I have a question if I have my connecting rods resize do I still have to use shims?

Line boring is very costly. If you're going to build a stock engine, it's hard to justify the cost. These engines ran well for years with shims.

It's your money, but the couple hours spent adjusting the shims is a lot cheaper than line boring.

The beauty of shimming is that as the bearings and crankshaft wears you can take out shims to restore the clearance and get many more thousands of operating hours before new bearings are required.

Gerald J.

When the WD's switched to WD45's they switched to shimmed mains and non-shimmed rods. I was a little nervous about shimming my mains, but once I understood it, it wasn't hard at all.

WF owner wrote:

I have a bunch of old used engine parts, including connecting rods. How do I tell if they are from a 201 (and need to be shimmed) or from a 226 (that doesn't need shimming)? Are they different part numbers?

There's a spec for the big end. Torque the cap by clamping the big end in your aluminum or brass jaws in your vise. Measure the bore size with an inside mic and compare.

"Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford

AND, I might add that over time, the bores may not be round anymore with a new shim pack in place. I had nearly .003 bigger vertically than horizontally on my old WC, when I started re-assembly. What I did was put .006 shim in and hone the bore round to size. It worked great and the crank rolled like a dream, ending up with .0022 to .0025 clearance.
If I had assembled it with a new shim pack, I would have had about .001 horizontally and .004 vertically and I didn't want that, nor did I want to pay for line boring. I just didn't have the shop time available to line bore it at work.

http://www.ae-ta.com
Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF

Hi guys so if I have this thing line board and the rods resize I can use their original bearings without having used the ship's or anything am I correct about this thanks

They are the same!

The dimensions you need are on the sheet I posted above.

Edited by Dick L - 12 Dec 2016 at 6:38pm

If I'm not mistaken how I understand the paperwork the main would be 2.250 in . With a .002 oil Clarence. But that is how I understand it I could be wrong? But I did not see A Rod bore diameter.

When in doubt measure! Placing the two shell together and measuring the outside with a mic will give you the diameter then less crush for the bore diameter.

Unless your buying the line bore machine to do it yourself it would not something to be concerned about. If your machine shop has questions as to what to line bore the inside diameter to, you need to find a different machine shop. The outside of the bearing shells for that engine will all be the same diameter even when the inside changes as it is fit to the new ground journals.

The chart I posted only gives the standard bearing journal diameters which is the size of standard bearings you would buy. I miss understood your question.

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Actually if you would measure the rod at the position I was measuring the bearing in the picture without the bearing you would have the proper diameter. When the rod is recut you only need to cut the cap. You would not dare cut the width or the hole would be to large.

Edited by Dick L - 13 Dec 2016 at 2:51pm

Mr Gerald do I have to buy a new style main bearing when I have this thing line bored

No. The bearings are the same, because originally it was bored WITH the shims, now it is bored the same dimension WITHOUT the shims.
Bill B

Allis B, IB, Low B, G, D10, JD M, 8KCAB, C152

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