M38 Engine Dilemma; Thinking on G503
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
M38 Engine Dilemma; Thinking on G503
Situation; I have a June 51 M38; it has a RMC engine SN 124184, part number 804380 on it. The one with the rust and aluminum balls in the cylinders. It has the bell housing and starter.
I also have a spare RMC engine; SN 56788; part number 64xxxx; turns freely. I learned that they are different engines; the early ones use ten bolt bell housings and different starters. No bell housing or starter on this one.
I was going to put the earlier engine in, but now I see the bell housing and starter won't fit; I am now inclined to rebuild the late one, rather than find a bell housing and starter. (Actually, I think I have a bell housing here somewhere. )
Mission: Choose an engine for my M38.
Anyway, I am leaning to using the late engine because I have never seen one and to have one in my M38 will be cool. I know, that is not a good reason. I was going to put this in a 5 paragraph field order format but forgot about it half way through.
Comments or snide remarks welcome.
I also have a spare RMC engine; SN 56788; part number 64xxxx; turns freely. I learned that they are different engines; the early ones use ten bolt bell housings and different starters. No bell housing or starter on this one.
I was going to put the earlier engine in, but now I see the bell housing and starter won't fit; I am now inclined to rebuild the late one, rather than find a bell housing and starter. (Actually, I think I have a bell housing here somewhere. )
Mission: Choose an engine for my M38.
Anyway, I am leaning to using the late engine because I have never seen one and to have one in my M38 will be cool. I know, that is not a good reason. I was going to put this in a 5 paragraph field order format but forgot about it half way through.
Comments or snide remarks welcome.
U. S. Army 28 years.
Armor Branch
Armor Branch
-
- Jeep Heaven
- Posts: 49841
- Joined: Sun Mar 02, 2008 12:37 pm
- Location: Proving Ground
Re: M38 Engine Dilemma; Thinking on G503
Late Bellhousing and the Matching Rear Plate will bolt right up to earlier engine with 124 Tooth Ring Gear, but you have to use a 129 Tooth Ring Gear and the late starter that is attached with 1/2" Bolts.
Remember, you will need the late adaptor plate,129 tooth ring gear and late Starter. The late Bellhousing, Adaptor Plate, Ring Gear, and Starter are same as M-38A1.
The ORD 9 SNL G-740 dated 1956 will confirm this.
Remember, you will need the late adaptor plate,129 tooth ring gear and late Starter. The late Bellhousing, Adaptor Plate, Ring Gear, and Starter are same as M-38A1.
The ORD 9 SNL G-740 dated 1956 will confirm this.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
Ok so as long as I change everything from the newer one to the early one it will work. The early one has no starter, bell housing or flywheel anyway. Good to know. Of course I read my SNL every day but I didn't think to check this out . Let that be a lesson to everyone. Study.
U. S. Army 28 years.
Armor Branch
Armor Branch
-
- Jeep Heaven
- Posts: 49841
- Joined: Sun Mar 02, 2008 12:37 pm
- Location: Proving Ground
Re: M38 Engine Dilemma; Thinking on G503
CJ-5 F-Head Bell housing and adapter Plate and 129 Tooth Ring Gear will work and the Late M-38/M-38A1 starter is a match for these parts. Stick with what I mentioned as CJ-3A and CJ-3B components were not always a match til early 53.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
Ok now you are confusing me with the cj5 and 3 talk. Am I reading this right; I can use the bell housing , engine plate, starter and flywheel now installed on the RMC 124000 motor, on the RMC56000 motor without any issues. Yes or no?
U. S. Army 28 years.
Armor Branch
Armor Branch
-
- Jeep Heaven
- Posts: 49841
- Joined: Sun Mar 02, 2008 12:37 pm
- Location: Proving Ground
Re: M38 Engine Dilemma; Thinking on G503
You can use the late bellhousing , plate and Starter on the early engine and vice versa. Later set up has a better starter. Remember to match ring gears with the set up you choose.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
Good. I only have the late setup so that solves the starter thing. Anyway it is good to know that I can use either block.
U. S. Army 28 years.
Armor Branch
Armor Branch
- DieFledermaus
- G-Second Lieutenant
- Posts: 515
- Joined: Tue Oct 14, 2003 6:37 pm
- Location: Lewes, DE 19958
Re: M38 Engine Dilemma; Thinking on G503
And just to complicate things, I have the early bellhousing, starter, and flywheel/ring gear for it should you want to go that route.
-Mike
-Mike
AUG 1944 MB, US NAVY
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
Good to know. If I decide to use the late block, and I want to only because it seems unique, and if it is cracked or something(Abrahams machine shop will magnaglux it), then I might need your parts. But from what I see, the new parts are backwards compatible onto old blocks.
Still not as much drama as restoring WW2 jeep!
Still not as much drama as restoring WW2 jeep!
U. S. Army 28 years.
Armor Branch
Armor Branch
- DieFledermaus
- G-Second Lieutenant
- Posts: 515
- Joined: Tue Oct 14, 2003 6:37 pm
- Location: Lewes, DE 19958
Re: M38 Engine Dilemma; Thinking on G503
I prefer the late set-up. The early starter switch was subject to moisture problems but if you are not fording creeks and swamps, I'm sure you'll be fine.
Cheers
Cheers
AUG 1944 MB, US NAVY
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
We have no creeks or swamps here; just corn fields and hogs. The Mississippi is frozen over though....
U. S. Army 28 years.
Armor Branch
Armor Branch
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
I discovered today that my late engine has the dreaded death crack under the distributor. It can be fixed but I will use the good, earlier, one.
U. S. Army 28 years.
Armor Branch
Armor Branch
- DieFledermaus
- G-Second Lieutenant
- Posts: 515
- Joined: Tue Oct 14, 2003 6:37 pm
- Location: Lewes, DE 19958
Re: M38 Engine Dilemma; Thinking on G503
I'll get out the parts you need.
-Mike
-Mike
AUG 1944 MB, US NAVY
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
- dpcd67
- G-General
- Posts: 11813
- Joined: Mon Jul 25, 2011 3:41 pm
- Location: Iowa
Re: M38 Engine Dilemma; Thinking on G503
Wait. Thanks but the new type parts on the 804380 number (cracked) engine will fit on the older 641087 engine if I read Joel's posts right.
Am I right?
Am I right?
U. S. Army 28 years.
Armor Branch
Armor Branch
- DieFledermaus
- G-Second Lieutenant
- Posts: 515
- Joined: Tue Oct 14, 2003 6:37 pm
- Location: Lewes, DE 19958
Re: M38 Engine Dilemma; Thinking on G503
In this discussion, the blocks are the same in the sense they will accept either early or late parts. If you have a late bellhousing, late starter, and a late flywheel (129 teeth, 13" diameter), then yes, you don't need anything from me.
-Mike
-Mike
AUG 1944 MB, US NAVY
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
MAR 1952 M38
APR 1952 M38
1957 F2A AERODROME TRAILER
1993 M101
A & P mechanic
Delaware 19958
Who is online
Users browsing this forum: No registered users and 34 guests