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Hello everyone. I'm new to this forum, but have been around the CJ-2A & G503 forums for a while now. Just learned about you guys a week or so ago. I am currently working on a Willys MB & just this week acquired an engine which seems to be out of an M38, but I'm not sure. Here's a few pics....

That casting 908756 is a 1955 & up casting. It most likely was a factory replacement shipped from Kaiser long after M38 engines finished their production run in Jun 1952. They were used primarily in the DJ3A and industrial engines after 1955. If it is a factory replacement engine it's serial on the flat above the water pump will be 4LRXXXXXX. If it came from a DJ3A it's serial will be 3AXXXXXX.

The military could have installed that replacement block in an M38 and 72206 could be the ID plate they attached to the engine showing which M38 it went into.

What is the head casting number?

What is the serial number on the flat above the water pump?

Your engine does have some telltale components that were used on the M38 installations.
Fuel pump (possibly a service replacement with primer)
Fording valve on PCV tube
coolant bypass hose from front of head to waterpump
forward facing drivers side engine mount (this will not mate to your MB)
Dual groove crankshaft pully
Vacuum T fitting on intake manifold

Per Wes's note - what is on the aluminum engine ID plate? Is there a serial number of any type on the flat area of the block, facing up, above the water pump/under the 90degree coolant bypass hose?

Tom

wesk wrote:....If it is a factory replacement engine it's serial on the flat above the water pump will be 4LRXXXXXX. If it came from a DJ3A it's serial will be 3AXXXXXX......What is the head casting number?

What is the serial number on the flat above the water pump?

Here is a pic of the water pump boss....



So far all I can read is what looks like a "7" close to the left edge, then a "13" near the center. I'll have to get some things out of the way before I can read anything else.

Jeff

TomM wrote:....forward facing drivers side engine mount (this will not mate to your MB)......Per Wes's note - what is on the aluminum engine ID plate? Is there a serial number of any type on the flat area of the block, facing up, above the water pump/under the 90degree coolant bypass hose?

Tom

I have another front engine plate from a CJ engine. The mounting ear appears to turn rearward rather than forward. Not sure everything else on the engine will match up to the CJ plate....

The aluminum engine plate appears to read "72206"....nothing else. All I can see on the water pump boss, so far, is part of a "7" near the left edge, then "13" near the center.

Jeff

Making some progress on the SN, but need another way to raise it. The 1st digit turns out to be a "M"....the 2nd digit is so light I'm not sure, but appears to be a "C" stamped up high....then there's some space & a "16"....can't see anything after that.

I'll post pics when I get back to my computer.

Jeff

I PM'ed you about your engine.

ScotchBrite red pad and spray brake cleaner the serial pad. Then hold a flashlite from the side and view numbers.

Here are some pics of the block SN boss. I tried b&w, negative, & blue just to see if it picked up any more detail....







Also, here is the head casting #'s....

The oil filter on the left came off the "M" engine, the one on the right was in the box of parts w/ my "J" engine.....



Any way to ID these filters as to what engine they belong with?

Jeff

TomM wrote:Your engine does have some telltale components that were used on the M38 installations......Fording valve on PCV tube....

Tom

Was there originally some linkage from the valve to the dash?

Jeff

Jeff,
On the M38 and M38A1 they used a dual push pull cable assembly that actuated both that valve and the one between the carb and air cleaner at the same time with a single knob.