willysmjeeps.com

hi group
would anyone know the last month built, and a guess the last serial numbers put out by willys of the m38, and can the casting numbers on the block, tell what year it was made
thanks bob

Bob,

The answers are here on the web site. http://www.willysmjeeps.com/downloads/M38SNDB.pdf

The casting numbers on the block give the series of the block. The serial number could help narrow down the year a wee bit. There is a date code that shows the day/month but not the year. Our data base does not enough serials listed to make a perfect stab at any engine's production date. The M38 used two block castings, 641087 (90% or so of production) and 804380 the tail end of production. The military's habit of replacing engines and shipping the old out for depot overhaul meant most M38 engines were not overhauled at the user's unit and installed back in the same jeep. Remember, Willys and kaiser made no attempt to match engine serials to chassis serials. M38 engines were all serialed consecutively meaning as example MC 65001 thru MC 85001 then RMC 85002 thru RMC 95000, then MC95001 and so on. The RMC's would be added in as the Army listed the need for so many replacement engines with that particular contract.

thanks much wes

hi wes. i picked up my m38 block today,with the casting number 804380
and the rmc 115324, isent that a low number, for the casting number?





thanks bob

No, not at all. As I have said the serials run consecutive irregardless of the casting numbers. With 62,000 M38's and about 50,000 spare engines, many of which were used in military power plants. The highest # I have in the database so far is RMC126145.

thanks again