How to tell a WD45 engine from a WD

In researching the difference between the engines of these two tractors I found lots of technical data and verbal descriptions, but was a little frustrated in looking for concise photos or videos on the subject.  After purchasing a WD45, I recorded and uploaded the follow video on Youtube: How to Tell an Allis Chalmers WD from a WD45.

Here is a link:

http://www.youtube.com/user/boydslittlefactory#p/a/u/0/MaOe2M-mawQ

Please feel free to check it out.

Boyd

You can tell a 45 block from a WD block because of the plate on the right side of the WD.You can't tell anything else from a "visual". Lot's of WD's had 45 guts put in them and measuring the stroke is the only way to tell the difference.You could put WD guts in a 45 block...but who would? Tall or short head will work on either.

Not completely accurate!!!

A ""WD" tractor that had a block split open from no antifreeze, could have easily had a  WD45 block installed, because the WD style block would have been discontinued in the late 1950's and replaced by the WD45 block. The innards of the engine in that case, could still be "WD" and not "WD45" even tho the block was the newer one.

when they went to the tall head, was it still the 201 block, or did they put the 226 block out there with it?

Yup after 50+ years you can find most any combo--  i had a WD45 with a 6 spring preasure plate instead of the 9 spring one it should of had !!

I  don't think the tall head would make any power over the 3 inch from what I have seen on the flow bench in stock form of coarse there is two versions of the 3 inch head the latter is better which is the one I am comparing. jmho

Appreciate the additional information - I will add a comment to update the video about that.  Boyd

Is it true that the WD pistons were flat topped and the WD45 were cupped? I have a WD with a WD45 block but when I had the head off the pistons were flat. I'm wondering if it's a true WD 45 engine or just the block that may have been replaced when the original cracked or something.

Back in 1953 when the WD-45 came out, it had a unique Engine Cylinder Block with no flat plate covering the push rods and lifters.

The difference in displacement came from the Crankshaft.

WD-45 had a 4 1/2" stroke, WD had 4" stroke.

Some time after that the WD block was discontinued, and the 45 block was used as a Service Replacement for WD's and Power Units.

A WD crank, pistons etc. were installed in a 45 block giving 201 cu.in.

G
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See Michael Crowe's Post in 'Farm Equipment Knowledge Base'

Follow up on WD WD-45 Pistons


Edited by Gary - 27 Dec 2020 at 10:56am

A legit WD-45 block in a WD chassis sure doesn't mean it is a real WD-45 engine, especially if there isn't an engine serial number stamped on that block behind the carburetor air hose. As said before, there was a point in time after 1953 where AC quit casting WC/WD blocks for parts replacement and forced you to purchase a new WD-45 BLOCK instead. Part number supercession is what it's called. Even if that WD-45 block has a serial number, it could have been a used block from a salvage yard and the engine still is 100% all WD inside.

It's not only the crankshaft stroke and the pistons/sleeves in a WD-45 engine, it also had a different manifold, muffler, carburetor and air cleaner assembly. It takes everything to make the total extra HP.