Need help with M38 Engine serial number

[Dave1811]

Hello Gents. I purchased a Willy's last week. I found the engine serial number and I am hoping someone with a lot more knowledge and experience is able to help me decipher what the letters/numbers mean. The first marking appears to be a M ( I am guessing) the rest of the number reads B-341560. Any help is extremely appreciated. I also found a decal restoration plate attached to the bottom of the engine. It appears it is a restored engine.

Thanks
4586
4587

[LarrBeard]

Interesting...

You start your post with "M38". At first glance that would make me believe you have an M38 or M38A1 - but from the plates you show you have a much older vehicle.

The tag on what looks like the frame has the stamp "MB 341560". This would indicate what you have is a Model "MB", not an "M38". The MB and GPW were the original WWII Jeeps. The "M38" was a 1950's vehicle.

In 1944 MB serial numbers 293233 through 402334 were built - a total of 109,103 units. If we guess a fairly steady run rate, that puts your vehicle as being built about the time of the D-Day landings in June of 1944.

From the plate on the engine, it is probably not the original engine. The engine in it was rebuilt, according to the plate, on March 22, 1945 and required only minor rework( rod and journal clean-up). The cylinders were not bored. The engine could have been reinstalled much later than the 1945 rebuild date.

Here are some links to check out:

http://www.rensjeep.com/sernum.html

And, a note:

Serial Number Stamped on the Frame

The MB frame has a tag that is stamped with the serial number in this format: MB123456. This tag can be found on the inside of the left frame rail just behind the bumper. It is a small zinc tag that is held in place with two small rivet pins. The number on this tag should match the number found on the data plate, but it will not match the engine serial number.

Serial Number Stamped on the Engine

The MB engine is stamped with the serial number in this format: MB123456. This stamping can be found on a rounded boss that is on the right side of the engine near the front of the block just below the head. It is under the oil filter cannister. On MBs, this number does not match either the data plate or frame numbers even if the original engine is still in the vehicle.


You have a genuinely historical vehicle - put up some pictures so we can drool over them.

[Dave1811]

Thank you very much for the informative e-mail. Your message regarding the engine makes a lot of sense. The body of the Jeep appears to be an M38. I have attached a few pictures. I definitely have my work cut out for me.

Thank you,
Dave459045914592

[gmwillys]

Dave,

Good looking M38.

The head is an MB Willys engine, being that the head is smooth with no ribs going front to rear.

The data plate is either a Army Depot overhaul tag, or an afiliated rebuilder. Ewillys.com had a whole article on the different companies who handled all the rebuilding of the WWII era Jeeps. I'll try and find the article in the morning and link it here.

[LarrBeard]

After WWII Jeeps were rebuilt, overhauled and refurbished everywhere. Several months ago we came across this overhaul plate from a Ordnance Depot in Esslingen, Germany.

Depot overhauled Jeeps from this era, like M1 rifles, are Mixmaster combinations of whatever part was at the front of the shelf for reissue. We found it interesting that the plate specifies the minimum octane rating for fuel as 68-octane.

Why specify this? It turns out that on post-war Germany, German refiners were making "near-gas" from coal, wood, methanol and other locally available materials. If you had to get gas from somewhere other than the motor pool, you might get 55-octane ersatzgaas.

Your Jeep is an interesting combination of parts. It looks good, it is plausible and it takes a group of Jeep heads to look at it and say "Hmmm ....". The gas tank in the rear looks like a NASCAR fuel cell.

What are you planning to do with it?

[Dave1811]

Thanks for the info. I am/was hoping to restore was much as I can. My job has me moving all over the place and it’s hard to find the time to work on the Jeep.

[LarrBeard]

It looks pretty good as is. Put some numbers on the hood, some unit markings on the bumpers and it's an ice cream/burger run vehicle!

Seriously - check the lube in the knuckles, transmission, transfer case and rear end as well as engine oil. If those stay happy - you're going to be happy.

[gmwillys]

A couple of examples of some of the Jeep rebuild facilities. I didn't get a chance to find exactly what I was looking for.

http://www.ewillys.com/2017/06/14/1943-photo-of-jeeps-at-england-depot-on-ebay/

http://www.ewillys.com/2016/03/03/line-of-m-38a1s-at-tooeles-army-depot/

[Dave1811]

Thank you for the links. Very much appreciate it.