Educate please

[scoutingranch]

I had a conversation with a guy that stated his military jeep (M38) has a different engine than a cj2 civilian engine.
Since I'm on the learning curve I didn't know if there was a difference. Please advise

mike

[LarrBeard]

I had a conversation with a guy that stated his military jeep (M38) has a different engine than a cj2 civilian engine.
Since I'm on the learning curve I didn't know if there was a difference. Please advise

mike

The M38 was based off the CJ-3A which was an improvement of the original CJ-2A.

Both used the basic L-134 (flathead) engine. But - the M38 had accessories that would be different. The ignition on the M38 would be the waterproof distributor - with different plug wires. Electrical connections would be different, waterproof vs. screw terminals. The oil filter was a bit different and some fuel pumps would/might have a priming lever.

I'm not an authority on little Jeeps, but I suspect that the M38 had some vacuum lines here and there that might have needed a bit different carburetor configuration. Air cleaner plumbing would differ because of the vacuum lines.

Once you got inside the engine - they would be the same - but if you had two complete engines with accessories side by side on engine stands, they would look different - but they are unmistakably cousins!

GMWillys can speak with a lot more wisdom on this.

[gmwillys]

LarrBeard is right on the money. The basic block and head are the same as in a CJ, but the accessories are the difference. Fording kits were installed meaning everything that pulled outside air in, or vented to the atmosphere were piped through the air cleaner, and the snorkel. The electrical components were waterproof, 24 volt and heavy duty. The front engine mounts and radiator were tied together with rods, so the power pack could be pulled as a unit. The grill was on hinges, and would be lowered for ease of engine removal/install.

[scoutingranch]

Thanks boys, now I'm much smarter, well sorta'. So that hinged grill was copied by Toyota for the FJ40, I'll be dipped. Ahhh' the things you learn.

[gmwillys]

To determine if you have an engine from a military M38 or M38A1 is by the serial number on the front deck of the block, behind the water pump. The prefix will start with an M, instead of a CJ, (or in some cases just a J) for the civilian market. The M38A1 had an F head 134, and their engine serial numbers started with MD.

"I'll be dipped" sounds like Vice Grip Garage.

[scoutingranch]

My old welding instructor used the term all the time so I've been using it for the last 50 years. Funny thing is, we all dipped Copenhagen so we all were dipped :)

[bmorgil]

Now I feel old, my grandmother on my mom's side was a farmer in Michigan in the 1920's 30's and 40's. She also said it all the time along with most farmers from that era in many parts of the USA. For them it referenced the vehicle known as the "Honey Dipper". A fertilizer wagon filled with SH*#. Hence the term "Well I'll be dipped in Sh@$!"

[okiemark]

That term has made its way to Oklahoma too. Think I remember saying and hearing it back in the 70's quite a bit.

[scoutingranch]

Now I feel old, my grandmother on my mom's side was a farmer in Michigan in the 1920's 30's and 40's. She also said it all the time along with most farmers from that era in many parts of the USA. For them it referenced the vehicle known as the "Honey Dipper". A fertilizer wagon filled with SH*#. Hence the term "Well I'll be dipped in Sh@$!"

Thank you B...that makes perfect sense and a good history lesson. And, now I understand what I've been eating all the years...

[LarrBeard]

It was a West Tennessee term as well.

If you modified it a bit to "Well, I'll be dipped in doody" you usually missed a whack from Momma, you just got glared at and told to "Watch your mouth young man"

[scoutingranch]

Now the fellow with the M38 has informed me that he is looking for an L134 industrial head, as that, is what they came with originally. Is this accurate?
I'm still learning, so I don't know beans.

[LarrBeard]

Cylinder heads for L-134 engines are the subject of much myth and legend.

If you Google "L-134 Cylinder Head", pretty soon you will be in information overload.

The "Kaiser Supersonic" head gave a 7.1 compression ratio and was similar to the high altitude head. The "standard" was about 6.48, maybe 5 HP difference..

Industrial heads may or may not have had lower compression ratios depending on what the researcher can find on his particular head. Most have been planed and measurements are no longer original.

The M38 engine may have had the same compression ratio as an industrial engine, but it would take a comparison of the part number cast in the head to see if they are the same casting.

https://forums.g503.com/viewtopic.php?t=237948

SO, the answer is a firm "Could be, but...".

[scoutingranch]

Thank you. I read the link. A good reminder for me to stay with CJ's and away from Mil Spec items as that stuff would drive me crazier.

[gmwillys]

Our '46 has the Kaiser Supersonic head. It has better then average performance in comparison to some other heeps that I've had.