WW2 buy back engines for early CJ'S

[MFender]

I am looking for information or a list of known buy back engines. I believe I may have one or at least the block. I have taken several photos of it and would like to post them. Blockcasting # 638632 CC W 3A-N1-CR-N2, date clock 12-5 with arrow on dot 6, J81899 above water pump, 3109 stamped upside down BEHIND water pump, Oval data behind oil filter has been ground with a half inch round stamp on left with a 3 stamped on upper right The engine has also been bored 100 over, has valve seats, been repaired at cylinder 2 and exhaust valve. On the deck: Cylinder 1 is stamped with a B, with cylinders 2 thru 4 stamped with C's. Thanks.

[sjalbert]

I haven't seen a list, but AFAIK clock blocks were all post war. Have you looked for a machining date on the oil pan flange near the rear bearing. All WWII Willy's blocks had that stamped.

[Joe Gopan]

And if your 1946 era CJ does have an engine with all the WWII Army features, these Jeep Engines were offered by the many surplus truck parts dealers everywhere in the USA. JC Whitney, Bergs, Warshawsky and the many big name surplus dealers all had NOS WWII Jeep engines for several years after the war. Their post WWII parts Catalogs were full of Jeep engines.

[MFender]

I haven't seen a list, but AFAIK clock blocks were all post war. Have you looked for a machining date on the oil pan flange near the rear bearing. All WWII Willy's blocks had that stamped.

I did find a 1/4" (approximate) Square which looks like a zero"0" in the center of it.

[sjalbert]

That would be a machinist's mark (as opposed to a machining date). Your block was not built as a military block.

[MFender]

That would be a machinist's mark (as opposed to a machining date). Your block was not built as a military block.

Thanks. that was my conclusion as well.

[Wolfman]

Don't have a list but do own a CJ-2a ( The Ugly Duckling ) with a military block. 638632 casting # and an oval pad behind the oil filter that has never been stamped or ground down. ( No. It is not for sale.)
I know nothing about it's past. I bought it from a farmer who drove it around his cabin in the U.P of Michigan. When it quit running, he brought it back to Indiana and I ended up buying it. Head gasket blown between #3 & #4 cyl. I know it is bored +.060 but never had the oil pan off. It has a chain drive cam. Don't remember if the block is stamped, over the water pump, or not. ?? I would have to go look.
I have retired ( sort of ) and plan to rebuild it ( the whole jeep ), but saying that, not much has changed with my life. My projects still seem to be last on the list. Guess it could be worse. I am not complaining.

[Joe Gopan]

only way yoou are going to find out is to check for the stamping on the gasket surface. There is no way to prove that your CJ-2A engine, even if it was a "buy back" was not bought at a surplus or used parts yards, or is a donor from a junk MB or another CJ-2A, too many years have gone by to really be sure.

[Wolfman]

Curiosity struck and the temp. got above freezing, so I went out for a look.
Interesting.
Jeep is a CJ-2a. Serial # 143585. Original, unmolested plates. Jeep looks to be original, except for the "Bubba Attack" the farmer had. Home made full top and brush guard/screen in front of the radiator. Outside painted School Bus Yellow !! Farmer I bought it from is also a school bus driver. Reason I nicknamed it " Ugly Duckling ".
The engine. Be interesting to know the tale on this one.
I am guessing the block is MB. Casting # is 638632 W3 AN1 CR N2. Definitely chain drive cam. Another interesting point. The top of the engine was painted jeep red, but when I cleaned the block, above the oil pan, to read the casting #, I found O.D. The oval pad, behind the oil filter ass. is un-stamped and not ground down. The top deck, above the water pump has a number, but again, looks like a Bubba Attack. The first letter was maybe a double stamped "J". At first I thought it was a "U" but could have just been a bad job of stamping a "J". Rest of the numbers were a bad job of stamping as well. 18118. ( J 18118 ). The letters were not in line, wrong font and the "1s" were replaced with the block letter "I". ??? Water pump looked to be F-134. Had a port for a heater return hose on the driver side and a plug for a by-pass hose, like on an F head engine, top driver side. Head, Willys, ribbed, casting number 800376. Maybe late CJ or M-38 ???
May be a buy back engine block ass. but don't think it was original to the jeep.
Didn't think to look at the oil pan. See if it has a skid plate on the oil pan.
Anyway, that is the rest of the story.

[Wolfman]

Weather finally straightened up and I got a look at the oil pan on the ugly duckling. It has a skid plate.

[Bruce W]

Curiosity struck and the temp. got above freezing, so I went out for a look.
Interesting.
Jeep is a CJ-2a. Serial # 143585. Original, unmolested plates. Jeep looks to be original, except for the "Bubba Attack" the farmer had. Home made full top and brush guard/screen in front of the radiator. Outside painted School Bus Yellow !! Farmer I bought it from is also a school bus driver. Reason I nicknamed it " Ugly Duckling ".
The engine. Be interesting to know the tale on this one.
I am guessing the block is MB. Casting # is 638632 W3 AN1 CR N2. Definitely chain drive cam. Another interesting point. The top of the engine was painted jeep red, but when I cleaned the block, above the oil pan, to read the casting #, I found O.D. The oval pad, behind the oil filter ass. is un-stamped and not ground down. The top deck, above the water pump has a number, but again, looks like a Bubba Attack. The first letter was maybe a double stamped "J". At first I thought it was a "U" but could have just been a bad job of stamping a "J". Rest of the numbers were a bad job of stamping as well. 18118. ( J 18118 ). The letters were not in line, wrong font and the "1s" were replaced with the block letter "I". ??? Water pump looked to be F-134. Had a port for a heater return hose on the driver side and a plug for a by-pass hose, like on an F head engine, top driver side. Head, Willys, ribbed, casting number 800376. Maybe late CJ or M-38 ???
May be a buy back engine block ass. but don't think it was original to the jeep.
Didn't think to look at the oil pan. See if it has a skid plate on the oil pan.
Anyway, that is the rest of the story.

Mike,
CJ2-A143585 should be a late '47. The original block would have been a 641087 casting. The 800376 head is M38. The water pump could have been installed as a replacement any time since the introduction of the bypass hose. Like Joel says, a lot can have happened in the last 70+ years. BW

[Wolfman]

Thanks for the intel, Bruce.
I am pretty sure this is a replacement engine. Don't know where it came from. The farmer I bought it from is a member of a "Hunters Club" that has a cabin in the U.P. of Michigan. That is where this CJ and two others came from. Every time I bump into one of the club members, they tell me some outrages story about something they did with " The old jeeps". One of the CJs went to Tennessee, with one of the club members and the other two were sold. They got those two titles crossed up. Still don't have that one straightened out. The farmers son-in-law, who is also one of the club members, has an automotive repair business. My guess he is at the bottom of this. He sells "Jasper Reman. Engines" but I don't think this is a Jasper. No tags. My guess is Army Surplus. There use to be an Army Surplus store in Indy. Closed now. I need to talk to the son-in-law about some other business anyway. I will grill him. See what I can find out.