F-head engine number CJ10125

[derekredmond]

Has anybody run across an engine number starting with "CJ", or have any idea where it would have come from?

Thanks.

Derek

[oldtime]

Block #125 must either be low production series of blocks that were used or some early vintage.
What’s the casting number ? Is there a date code ?

[derekredmond]

Thanks Oldtime.  These are photos that were sent to me.  Here's the casting number.  This is a 3B that was assembled at the Willys Canada plant, but other Jeeps I have seen from there have 4J engine numbers in the normal sequence. 

[oldtime]

The 8xxxxx series of part numbers begins usage beginning in the 1953 model year so the block itself must be from sometime after late 1952.
Beyond that I can only guess and my guesses are mostly wrong.
I would have maybe guessed “C” for Canada but you seem to have already ruled that one out.
If the block is not native to the Jeep then perhaps the “C” designation may be relative to some other specific engine application.
The only other criteria for “C” that I can think of is when it’s used as a suffix to imply .002 undersize piston pins.

[derekredmond]

OK, thanks.  That kind of date suggests the engine is not original to the Jeep, which I neglected to mention is a '62.  So maybe the engine is from some other application.  Funny that it would have CJ as a prefix, when the engines in the CJ-3B and CJ-5 have the 4J prefix.

Derek

[Scott Blystone]

I checked my 4 engines, no cj code. Two are known from wagons purchased late 50s in western NY. Other 2 are from PA and from a 53 3b and a 55 cj5. Wagon numbers start 1J.

[64CJ5]

Could the block have been machined and lost the original stamping and then been re-stamped? 

[derekredmond]

Thanks guys.

Could maybe have been stamped when rebuilt, but this does look like a factory stamping, and mostly if they get machined off they are just left blank. 

Derek

[oldtime]

This looks to me like an opportunity to post up some known original engine stamping for comparison.
I only have a single engine stamping to donate for comparative analysis.
This one is from a very early 1949 CJ-3A.

[SteveKfl]

Here's one to maybe have fun with.  From my DJ3A where the frame assembly serial number falls around Sept 1961, I have often wondered if the engine was done in March 61 and over stamped with the "361", or does it mean something else?

[Bob W]

Interesting serial number. I have never seen a CJ prefix before. Looks like the CJ 10 is kinda going up hill and then the 125 levels out. By the 1950s stock engine serial numbers were fairly straight. Of course special engines had hand stamped serial numbers. Oldtime's photo shows the 59th CJ-3A engine. This was probably hand stamped. Later on the hyphen was not included in 3Js. See Steve's engine for the common type 3J prefix serial number. Interestingly the two "1"s are different fonts. Below is an example of a 4J prefix on a 806279 block.

[oldtime]

Given enough known examples from various timelines it may be feasible to estimate originality of unverified  engine numbers via the subtle font changes observed over time ?
As Bob brought up about the 1949 example, it clearly used a hyphen and also the top of the “j” was crossed. So given more examples we might suppose that those 2 traits may have been common during that period