Bob Call

Engine Block Foundry Mark

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I'm trying to sort out the foundry code marks found on Chrysler, DeSoto, Dodge, Plymouth, industrial and marine engines. These codes are usually next to the casting date code and casting number code. There are three codes I am aware of: CWC; A1, A-1 or AI; and HH.

What code is on your block? What brand, year, type and size is your engine? Is the engine from a US or Canadian made vehicle? Do you know definitely what foundry poured your block?

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Benefits of AACA Membership.

I am also curious about the numbers on an engine block in an old car I just removed from a farm In South Dakota.

The engine is a split six and the numbers are CWC 525030. Does this mean it is a Chrysler product? I'm having difficulty identifying the car.

Thanks

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I don't know what the codes mean but as far as I know there was only one casting plant in the early days of Chrysler and that was Dodge Main in Detroit. All Plymouth,Dodge,DeSoto and Chrysler engine blocks ,trucks included, were cast there even the blocks for Canadian vehicles. In 1937 Canada got it's own casting plant across the river from Detroit in Windsor Ontario. It was just pulled down about 2 or 3 years ago and Dodge Main is gone as well.

But I am interested in the codes too. I know if a number like '52' is cast in the side of the later blocks it means '1952' and can tell you whether you have a replacement engine in your early vehicle since the flat heads were all virtually interchangable.

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Bob, I can't help you directly but I can share that I've also been very curious about various other marks on the blocks of Chrysler-product flathead-6 engines. For instance, there are six thumbnail-size bosses cast high on the left side of each block, each one signifying the cylinder adjacent to it. The 1935 Plymouth engine I'm working on right now -- I don't have my notes with me at the moment -- has a single letter stamped in each boss: A, C, C, A, B, C, or something of that sort. Are these instructions to the assembly line workers? Also, following the six-digit head and block part nos. it's common to see a suffix such as "- 3." What does that code mean? All of my block and head castings have a stylized "NH" (I believe it is) cast into them. I've always thought it was the name of the foundry ... but now I'm unsure. There are also stampings in various places on the engine deck, hidden by the head and head gasket when the engine is assembled. For instance, someone stamped a "Z" in the head of my 35P engine. This is a code of some sort. Do you know what any of these mean? Thanks!

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It's possible that each of those letters indicates a variation in bore diameter from standard. Pistons have always been a selective fit because both they and the bores will vary a few thou from the actual standard. I'm not sure abour Chrysler engines, but I know that 'ABC' were used to indicate: A = standard,B = 0.002" overbore and C = 0.005" overbore on new blocks from another manufacturer. This made it simple for the assembly person to choose the correct diameter piston for each hole from his stock. Variations in diameters of both bores and pistons constitute the basic reason that pistons are numbered for their holes and must be returned to the same holes if they are to be re-used after removal.

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I forgot I do know what those punched letters on the boss mean I thought everyone was referring to the cast numers and letters. The punched letters are 'oversize' and 'undersize' codes for the engine but the ones on early cars meant the connecting rod big end as well as the cylinder bore. The early engines had a round area on each side of the engine serial number boss where the sizing letters were punched on.

I found my documents on the letters punched in by the line assemblers:

A A =Standard engine (sometimes just left blank)

B BA = Main and connecting rods .010" smaller

A CC =Connecting rods .005" larger

B AA =Cylinder bores .020" larger

A AB B= .020" overbore,crankshaft mains are

.010" smaller and connecting rods are .005" larger.

I've also found 'stars' stamped into the same boss but I don't know what that means yet.

The letters I have never been able to decipher are the cast ones on the side of the block. 'NH' is very common. And they always seem to have a 'time clock' cast in them with the time of day the casting was made. The heads had the casting number cast in them. It's always about 2 numbers away from the actually part number of the head. They also usually had the car's model letter cast in them such as 'PC','PD','PE' etc. Hope some of this helps.

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Guys

Thanks for the info. One thing certain, Walter P. didn't waste any misfit or left over parts, just put them together and stamped mysterious codes on everything.

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CWC is the foundry where this was cast: Campbell Wyant Cannon

Three men started it: Donald Campbell, Ira Wyant, and George Cannon.

Now CWC Textron last I knew

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1 hour ago, Wascator said:

CWC is the foundry where this was cast: Campbell Wyant Cannon

Three men started it: Donald Campbell, Ira Wyant, and George Cannon.

Now CWC Textron last I knew

I thought that Dodge had its own foundry?

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Dodge Brothers did have their own foundry.  That was the main reason Walter P. Chrysler wanted the company.    He wanted to get into the low price field (against Ford, Chevrolet) but the cost of parts, in particular castings, was holding him back.  Having his own foundry he could cast all his needed parts and eliminate paying the supplier for the parts and the supplier's profit margin.

 

Chrysler acquired Dodge Brothers in late July, 1928.   From that point Chrysler would have used Dodge Brothers facilities.   Before that Chrysler would have used CWC. 

 

By the way, before Chrysler of Canada opened their engine plant in 1938 all engines were imported from Detroit.

 

 

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