I have some time before I get close to this, but I want to start thinking about this and plan.
My M38 came with a MB Engine and 12V system to start up the engine. None of the gauges worked and the only lights that worked were the headlights. I haven’t checked if the gauges and other lights are 12V or 24V, but I assume it would be 24V.
- Can I completely convert to a 24V with the MB engine?
- Can go 24V electrical, but convert down to 12V for the engine?
I would eventually find a MC engine, but I am just getting it back together. Just want to prepare for getting an MC engine in the future.
M38 - MB Engine | 12V or 24V?
Moderators: TomM, Moderator, wesk
- JeepFregia
- Member
- Posts: 19
- Joined: Sun Sep 06, 2020 6:00 pm
- Location: Hardin, TX
M38 - MB Engine | 12V or 24V?
Ryan F
1951 M38
1951 M38
- JeepFregia
- Member
- Posts: 19
- Joined: Sun Sep 06, 2020 6:00 pm
- Location: Hardin, TX
First determine weather your engine is still chain drive cam or gear drive modified.

Second determine which flywheel you have and which bell housing. Here are examples:

Early vs late M38. WWII is very similar to early M38.
Determine which casting number block you have:

WWII 638632 casting has serial number on side behind oil filter bracket.
Determine if your front engine mount plate is WWII Mb:

Or the postwar civvy/M38:

Find out the tooth count of your flywheel. Early WWII and CJ are 97 tooth



Second determine which flywheel you have and which bell housing. Here are examples:

Early vs late M38. WWII is very similar to early M38.
Determine which casting number block you have:


WWII 638632 casting has serial number on side behind oil filter bracket.
Determine if your front engine mount plate is WWII Mb:

Or the postwar civvy/M38:

Find out the tooth count of your flywheel. Early WWII and CJ are 97 tooth

Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
- JeepFregia
- Member
- Posts: 19
- Joined: Sun Sep 06, 2020 6:00 pm
- Location: Hardin, TX
Here is my Engine, Casting Number is 638632 and for sure has a MB Serial Number. Although I could not tell you the rest off the top of my head. And I do have the Early M38 Bell Housing cover plate.

Also, the Transmission does not look to be the one that was used on the M38's with the vented housing cover. And the housing go up the shifter does not look like the correct one.

I will have to get the rest of the info on the timing cover drive, the flywheel tooth count and the Front mount.

Also, the Transmission does not look to be the one that was used on the M38's with the vented housing cover. And the housing go up the shifter does not look like the correct one.

I will have to get the rest of the info on the timing cover drive, the flywheel tooth count and the Front mount.
Ryan F
1951 M38
1951 M38