M-38

[Buckweet]

Hi there .. I am a newbie but had questions about the m-38 that I finally dragged into the shop. It has been in the family for over 50 years and needs some serious attention . I specifically have questions about the motor as it was replaced in the 70s? I believe with a Buick V6. Not sure where to go with it as it does not run .

[bmorgil]

Welcome Buckweet, post some pictures of your M38. The direction to take your project, is as wide as your imagination. Take a look at this Jeep with a V6.

[Buckweet]

5924592259215921
Welcome Buckweet, post some pictures of your M38. The direction to take your project, is as wide as your imagination. Take a look at this Jeep with a V6.

I hope this helps. Thanks for the response. Ok I might be a little challenged on adding photos. I do have the tags off of it that helps. Also not the shifting. If I remember correctly it has a high/low and Overdrove.. so not sure if it is the original transmission.. probable not.

[Buckweet]

Also note* I am not proficient with typing on a phone!!

[bmorgil]

Oh man that thing is a great looking project! A considerable amount of it is still there and it is good shape. That should be a lot of fun that's for sure.

[TJones]

Welcome Buckweet...
That’s a fine looking M38 you have to start with!!!!
Let me know if you have any questions, I started with a 52 M38 with a Buick 225 V6 odd fire in it as well about 2.5 years ago.
Don’t mean to discourage ya but I took my good ole time doing it, so if you have any questions don’t be afraid to ask as the other Wise Men say “there is no such thing as a dumb question” on here!!!
Good times are coming your way !!

[Buckweet]

Thanks for the response. So I drained the oil ... except it was mostly water. Which I take as a bad sign. The engine fired about 6 years ago and was able to drive it briefly. Long story short it was in repair mode in a field when it rained with hood open and carb cover off. Am contemplating a rebuild if the engine I have . Can you still get parts for that V6?. Or is there way to tell what exactly it is as I don’t see any tags on it. Any thoughts on the transmission and if that is a standard mod? Any other options I am open too.

[TJones]

Oh my Buckweet that is not a good sign, I’m not sure where you live as far as winter months go but if it’s anything like NE Ohio the winter months get a little breezy and it could of easily froze and possibly cracked the block somewhere. As far as getting parts we need to figure out which Buick V6 you have and there are different locations of where the numbers are depending on which V6 you have, I’m assuming it’s either a 198ci or a 225ci, I will post the location to look for the numbers to tell which one you have and yes parts are still available for all.
The transmission is probably a stock T-90 with a overdrive bolted to the transfer case, I have the same set up on mine.

[TJones]

Here you go Buckweet,
Where to find the numbers to verify your casting # and which engine you have.
I would be willing to bet that what you have is a 225CI Odd Fire V6, that is what I had in mine and I switched to a Even Fire 4.1 252CI.
They are the same blocks (225,231, & 252 CI) they just have different bore and slightly different stroke in them.
Also I have attached an article by Novak on the Buick V6


5925

https://www.nmr.mgh.harvard.edu/~reese/BuickV6CastingNumbersandInternalSpecs.pdf

https://www.novak-adapt.com/knowledge/engines/about/buick/buick-90-v6/

[bmorgil]

Welcome Buckweet, post some pictures of your M38. The direction to take your project, is as wide as your imagination. Take a look at this Jeep with a V6.

Whoops forgot the link, but you just met him! https://willysjeepforum.kaiserwillys.com/showthread.php?1772-New-to-the-Forum

[LarrBeard]

Ditto. Pelago had a lot less to start with!

For my curiosity, is this an M38 or an M38A1, I can't tell the difference.

[TJones]

It’s a M38 Larrbeard the M38A1 is a copy after the CJ5 body style

[LarrBeard]

Do both of them have the hinged grille?

See, I'm getting smarter just hangin' with you guys.

[TJones]

Do both of them have the hinged grille?

See, I'm getting smarter just hangin' with you guys.

I do believe the M38A1 does have the hinged grill LarrBeard, and you mean THOSE guys not me I am still learning from the trial and error method:rolleyes::rolleyes:

[gmwillys]

The M38 all had the hinged grill, while only the first two or three years of the M38A1 had the hinges. The engine was set up in a power pack form, to where they could be readily pulled with the least amount of disassembly. We use the same method today in the current mil spec vehicles.

[bmorgil]

I think the early M38A1 is similar to the CJ3B right?

[gmwillys]

Just the engine. The CJ3B was a flat fender body, but to fit the F head 134, they raised the cowl four inches. The hood was also raised on the sides the same. The M38A1 came out in '52 but was the predecessor to the '55 CJ5. The M38s were produced for four years, '49-'52.

[TJones]

Now I’m getting smarter hanging out with you guys!!!!

[Buckweet]

5931. Ok this is great. The number is 1349430. It has a 7-13 above it but not sure if that is needed. Sadly it appears there is some rust in initial investigation. I don’t think marvel oil will fix it properly! I’ll know more as I get a little further in. Cheers!

[Buckweet]

Looks like a 198. Thanks for the info. So either I rebuild or replace not sure yet. Where’s the best place to get parts for a 198? Or if I replaced it where would I look?

[LarrBeard]

TJones can tell you where NOT to go!!!!

[Buckweet]

Ok I am still learning about threads and posting. I think I missed the last one. Anyway looks like it is a 198 engine. Parts seem unavailable from what I read. The transmission might be an issue as it stated in the article that they did not use the T90 with Buick v6.. does that sound correct??

[TJones]

Buckweet if your dead set on rebuilding what you have we can find the parts you’ll need. My personal thoughts would be to try and find a good 231 CI even fire engine that would bolt right in what you have.
As far as the transmission goes you need to crawl under your rig with a flashlight and on the drivers side of the Tranny there should be a number cast right into the case that will tell you which transmission you have, they do make adapters to bolt a Buick V6 to the standard T-90 3 speed that originally came in the M38’s.
See attached picture for location
So maybe we need to start there to see what options you really have.
Keep us posted.


5932

[Buckweet]

Sounds good. I would be looking for a 231 Replacement. I’ll check on the transmission this afternoon. I have been looking online for 231s and am defiantly out of my element there. Once I grasp the transmission model I would defiantly appreciate some knowledge on the correct engine.

[TJones]

We will get you headed in the right direction Buckweet, where are you located may we ask?
It might be better if we know the general vicinity to locate what you are looking for or what else you may need to get it on the road again.

[Buckweet]

We will get you headed in the right direction Buckweet, where are you located may we ask?
It might be better if we know the general vicinity to locate what you are looking for or what else you may need to get it on the road again.

Well Iam in a little state called Vermont...thus the rust... transmission is a T-90A-1. There is a tag below it that read 10-8-53..wasn’t sure what that means. Anyway I have learned more about this Jeep in the last few days then I did the last 30 years! So thanks again! If the transmission is acceptable what are motor options?

[TJones]

As bmorgil said earlier Buckweet, “your options are as wide as your imagination”
The ball is in your court now Buddy, you can rebuild what you have if the block is not cracked from the water that was in it, we can look around for a 231 even fire motor, we can get a 231 built for ya, or we can even put it back to stock and put a 4 cylinder back in it that they originally had and 1 of the other Seniors would be able to tell us what that was, I’m thinking it was a L-134.

[gmwillys]

Your options are pretty much endless. The T-90 is more than adequate to handle up to a V-8 without issue. You have an overdrive already installed, so you'll be able to get a bit better top end speed out of it, so that will be a bonus.

[bmorgil]

I think we need to see if you need a pilots licenses to "fly" TJones's rocket ship, before you guy's stick a V8 in there gmwillys! A true hot roder you are, to plant that suggestion! Of course, I love it.

All true stuff from the Boy's on the powertrain Buckweet. It is strong enough to hold up under any modern naturally aspirated 1/2 ton pickup. The trans, transfer case and axles will have no issues. The factory driveshafts however, will have many issues. As built from the factory, it would be disastrous to put the existing driveshaft assemblies in a high speed L4/V6 or V8 application. Also when running an Overdrive, it will be imperative to pay attention to your driveshaft angles when you get it back together. Suffice it to say an Overdrive can greatly increase the driveshaft speed (RPM).

The "tag" you reference could be a build tag or, if it is cast into the case itself, it is the date the casting was poured. That would mean it was cast or built on November 8th of 1953. Lets see a picture of that.

[gmwillys]

There is no replacement for displacement.

[bmorgil]

There is no replacement for displacement.

Haha! I agree. The man who I preferred to machine all my engines, a guy who did work for AJ Foyt, used to say "The only replacement for cubic inches, is cubic dollars".

[TJones]

Haha! I agree. The man who I preferred to machine all my engines, a guy who did work for AJ Foyt, used to say "The only replacement for cubic inches, is cubic dollars".


Both of you guy's are Hilarious:D:D

You are going to scare Poor Buckweet off.......

[Buckweet]

5933. It appears to be a plate with two screws....my question is if it is an m-38 .. how is a 63 transmission it .. was that a modification?.. and yes you are starting to concern me on the details but I haven’t thrown in the towel yet.

[Buckweet]

5933. It appears to be a plate with two screws....my question is if it is an m-38 .. how is a 63 transmission it .. was that a modification?.. and yes you are starting to concern me on the details but I haven’t thrown in the towel yet.5934. Also it appears water has gotten in thru the muffler manifold(it was gone).. might be the source of the problem... how big of an issue is pitying on the cylinder walls.. I think I know the answer.

[TJones]

Is that the engine casting?
It looks like the number for the 198 Buick block.

[TJones]

It all can be salvaged Buckweet!!
Unless the block is cracked, and if it is it’s scrap!!
I’m checking with a buddy that has a warehouse full of Buick V6’s to see if he has a running 198 or 231 replacement we can use.

[Buckweet]

Sorry.. sent the wrong photo. Here is a pic of the tag on the transmission5938

[bmorgil]

That is the casting mark. It is actualy cast right into the case. It is a mirror image of the identification tag that is put into the mold every time a pour is made. That case was cast on November the 8th, 1953.

[Buckweet]

That is the casting mark. It is actualy cast right into the case. It is a mirror image of the identification tag that is put into the mold every time a pour is made. That case was cast on November the 8th, 1953.
well got the motor out and somewhat degreased to inspect it. I do not see any cracks and all of the antifreeze seemed to be in it. Could it be cracked internally? It WILL not turn over and some of the cylinder heads got hit pretty hard with corrosion. Is there a trick to trying to get those to move?594859485949

[okiemark]

You might try using diesel to see if that will help loosen it up. It might be all or only one piston stuck. Or you could go ahead and take off the rod caps and remover the crank and try whacking them with a 2x4 and hammer to see if you can move them.

[LarrBeard]

You might try using diesel to see if that will help loosen it up.

50-50 diesel and DOT-3 brake fluid works well also.

[gmwillys]

A cocktail of diesel fuel, transmission fluid, P. B. Blaster, and pressure should get things freed up. Soak the cylinders, and use the 2X4 and a hammer to rap the pistons from time to time. If you can remove the crank shaft, that would help, but with a V6, you are bound to be not able to get to all the connecting rod caps.

The biggest thing to remember is that you don't want to get in a hurry.

[TJones]

WOW Buckweet you have been busy this weekend, everything that the guys are telling you is wisdom. Let them soak well with the cocktail mixture and like they said it will eventually break free.
If it was full of antifreeze more than likely it didn’t crack the block anywhere, the water in the oil was probably what came in through the carburetor and settled in the oil pan when the hood was left open with no air cleaner on it.

[gmwillys]

Just in case you want more options to your build, here is a supply of L 134 engines going up for sale.

http://www.ewillys.com/2020/04/29/l-heads-f-heads-college-station-tx/#comments

[5JeepsAz]

Cubic dollars! That's some funny.

[Buckweet]

Well I have been taking a diesel bath for a while now. I have 3 cylinders freed up and suspect I can get the others after a bit more coaxing. If I have success ,what tolerances would be acceptable on the cylinder walls. After cleaning and some honing one is at 3.630 inches. I know they are 3-5/8 bore and looks like a can get new rings for that engine. Can I hone more or will it be too much?

[bmorgil]

Buckweet, it will need to be re-bored and oversize pistons and rings installed. Your machine shop will be able to tell you how much oversize will be required to "clean it up".

[okiemark]

Are there any rust pits you can't hone out?

[gmwillys]

A machine shop would be best to check the bore size for out of round and diameter. You'll have to have the pistons ordered per the size that the overbore was needed, along with rings. Cutting corners now would cost three fold in the long run.

[TJones]

Buckweet I’m with bmorgil and gmwillys on getting a machine shop to look at it, they will be able to tell you if the cylinders are egg shaped or if the block needs bored to clean up the cylinder walls. More importantly I would want the block cleaned in a hot tank of Muriatic Acid over night to clean out the oil journals for the cam and crankshaft and the water jackets as well if they plugged with gunk or rust your wasting your time and MONEY doing it without cleaning the block first.

[Buckweet]

Ok thats what I figured.. There are some rust pits in there that wont hone out. So is it worth it for that 198 or should I be looking for a replacement motor?

[LarrBeard]

I'd let a machine shop look it over and get their opinion if the rust pits will clean up with an overbore. Don't give up too soon, but as pilots say; "Know when it's time to pull the handles and leave".