To modify or not?

[rwkehler]

I'm thinking should I modify my 230-6 or put completely different motor in or leave it original in my M43
has any one modified theirs ?
changed carbs to a 2 bbl ,electronic ignition , header?
tnx
R

[monkeymissile]

Modifications are always a personal decision and you'll find purists and modifiers alike on this site. Search around a bit more and you'll find lots of info on re-power options.
I'm replying because I have an M43 as well and can tell you what my plans are for it.

So far I've put in the electronic ignition module which I think is great.
I plan to:
- swap out the generator for an alternator for more reliable and consistent power
- add locking front hubs to save drivetrain wear
- upgrade the wiring harness to add a few do-dads (stereo, additional lighting, backup lights+camera, on-board air). Hence the alternator upgrade..

I researched headers for the 230, but there aren't any off-the-shelf options that don't require mods elsewhere to fit and space is really tight.
I'll probably rebuild the engine at some point, but since I'm not interested in more speed, I'm not going to re-power (although a bio-diesel setup would be cool!).

I'm sure you'll get plenty of additional feedback and advice from the vastly more knowledgeable folks on here; they've all been tremendously helpful.

[Master Yota]

MM has summed it up rather well.

What do you want the truck to do in the end? Can the 230 accomplish those goals with some help? Will it break the bank to modify the 230, or is it cheaper to repower with a different engine? Quite often an engine swap will garner better road speeds, better mileage, and sometimes a nicer shifting transmission. The only real way to keep purists happy is to leave it bone stock. Any mod will illicit furrowed eyebrows and frowns...(If you care at all about what others think!)

In the end, its your truck, so long as your mods put a smile on your face and make you happy, then all is fair game...

[rwkehler]

Hi guys,
Hey thanks for the feedback. on my truck it has that water resistent distributor which i don't believe i will ever need. I may sell it?
The motor that is in there came from a same year M37 so not original.
Here's the long and short of it! I think THESE trucks are cool!! there i said it, the M43's are nice but these are so different from what we don't have up here in the center of Canada.
When I drive this down the strip the head snaps will sound like popcorn.
I'm not worried about speed as well, If I wanted that I would just change out the diffs.
A friend said to add the two barrel carb change the cam and add a header with decent muffler and it will bump the stock 92hp to 150hp and be better on fuel.
Thats what I'm leaning to. The outside of the truck will still look the same but it will run better (hopefully).
And as for this forum , hell yeah i'm finding stuff out that I cant find anywhere else. And its really nice to read a reply from someone else who has a M43!
Thanks
R
P.S. Attached a pic.

[8543bob]

Good AM I dont know, but adding a two barrel carb, changing the cam and adding a header, I think you are playing with fire and will get burnt. These engines, with the long stroke, are known to through rods, stock, fire them up and beware. Re-power if you want more gusto.
J ust my thoughts. GOOD LUCK BOB

[rwkehler]

Hey Tnx maybe just swap motors.
this one looks good?

[Master Yota]

Virtually (and I use the term loosely) any inline 6cyl engine will fit. Road speed is more a limitation of the 230's rpm band than the diffs. I would find it most difficult to belive that a simply cam and carb swap, with a header, will net you almost 60 more hp. With the available compression ratio around 6:1, I would suggest that your friend is dreaming, or just unfamiliar with these engines. If you were to include about 2k's worth of maching to that engine, it might be feasable with shaving the head, porting and polishing of the intake and exhaust, and some flow relief cuts in the combustion chamber, but its frankly not worth the money, as pointed out, the bottom ends are weak. I would consider a Jeep 258 (4.2L) engine if your looking for reliability and an engine that won't look out of place when you pop the hood. There are lots of recomendations for the 4cyl Cummins as well, but they are not cheap, or easy to find up here in the frozen north, and IMO not worth the cost of installation. With the divorced Tcase, any engine swap becomes almost a no brainer, Mopar, GM, Ford, are all readily available units, cheap to procur, and has been done often enough that all the info you need to do so is readily available.

Is your M43 a Canadian unit? All the Canadian M37's had a 251ci. engine, but I'm not certain if that was a requirement of all the "M" series vehicles, or just the M37.

[rwkehler]

The trucks out of Superior WI and my friend did exaggerate a bit on the upgrade and true he is not familiar with these engines.
I have access to a 4.0l jeep engine if i do swap. the hemi 6 is just a thought (too expensive).

[MSeriesRebuild]

You can look at a modified 230 on our website, under the rebuilt engines link on the services page. 40 additional horsepower is more realistic, not 60. More RPM than around 3,300 is not realistic either, however the correct cam grind will greatly facilitate the available torque. This in conjunction with a 4.89 gear change will make a night / day difference from stock. How you should proceed should be based on your desired end use of the truck; I couldn't comment on that in an intelligent fashion without further information.

[k8icu]

To modify or to not modify that is the question.... didn't Shakespeer write that...

I agree with some of the posts here. It is a very personal thing. I have had my M37 project in mind for a good 12 years or before I got an M37 to modify. And if the truck handn't been as rusty or as already modified by prior owners I would have given pause to going a head with my project. But in my case the truck was IMO to far gone from stock to take it back that way. Thus it gave me the green light to move with my project (as slow as it may be).

I feel that unless you want to learn old school "hot roding" the 230 is not worth the effort to try and hop it up. Can the motor be "hot rodded"? Yes it can, but the number of persons who know how to do this work is getting smaller and smaller each day. So the knowledge is being lost. Also the available parts are getting smaller too. As was stated the amount of money needed to modify it right to make it go fast in todays economy is probably not worth it. Also as stated with a divorced transfer case it would be eaiser and cheeper to pull a motor and trans out of almost any vehicle (cept front wheel drive) and put it into the M37 providing it would fit. Then the world of aftermarket performance parts is wide open to you espically if it is a common small block V8 motor. GM 350, Ford 351, Chrysler 360 etc. If you want to modify the truck this I think is a cheeper way to go then trying to hop up the original motor.

Now to keep it stock isn't a bad thing either so long as you understand that the truck is not a speed wagon. I enjoy looking at a well restored stock truck just as much as I do a modified truck. But stock trucks are 45-50 MPH max. Not good for highway driving around Chicago during rush hour. Great for taking the back roads and seeing the heart of the country though.

It's up to you and it's your choice. You have to decide what is best for you. Good luck with your project and keep us posted.

Joe

[MSeriesRebuild]

60 - 65 MPH is very possible with 4.89 gearing and a good stock engine or a well rebuilt stock engine that is set up correctly. Some of the short cut builds we read about here and at other sources from time to time, I'd be nervous about; not saying they wouldn't stand the pressure, but in my mind there would always be that element of doubt that would make me uneasy about punching it to the max. If I know what went into a build as far as quality parts and workmanship; then I have no reservations about doing that.

[rwkehler]

hey guys!
Thanks for the great response ,
I really picked a good topic to discuss. and it gives me a lot to think about....Hmmm!
I believe it comes down to cost and result,
if I wanted it original then to rebuild to stock would be the way to go.
if I wanted to be better than stock, modifying would be the way to go.
both are costly and wouldn't give the result i 'm looking for. reliability not speed.
I think a engine swap is the most efficient way to go.
but no v8's for this girl .
what would be the best 6 cyl swap?
thoughts?

tnx R

[Master Yota]

The standard theory of thought is that the 4.0L jeep engine is great is what it comes in, but its not often swapped into anything else. This may be for reasons other than its length, but probably not too many. The 4.0L has the rpm band to accomodate the stock gearing, which means a financial savings if you dont' need to tear down the diffs to re-gear. And, its torque output isn't so radical that you'll risk breaking the driveline with it. The 4.0L also has a respectable aftermarket following so upgrades and adapters are available to swap a stout 2wd transmission (T18, T19, NP435, Sm465, NV4500 etc..) to connect it to the stock Tcase.

The dodge slant 6 is also a good candidate, but appears to have clearance issues with the distributor. I've never seen one though, so I can be 100% certain of this. The GM 235 or 250 6cyls. would also be a reasonable choice, although neither of them have the rpm band that he 4.0L does. But, its still alot better than the 230! Don't discount the smaller v8's too early, the 302,305, and 318 are all excellent powerplant choices. And they can all be found for a song if you find the right parts truck for the right price...

[rwkehler]

so.. other than the fact that the 4.0 distributor and intake/exhaust is on the other side, is it compatible? and will fit?
the 230 runs so i'll use that until I can find a more suitable power plant.

[Joe]

Keep in mind that if you up the power, via hot-rodding the original engine or via an engine swap, then you should give serious consideration to upgrading the brakes and steering. I suspect that hot rod parts for a 230CI would be very hard to find and the 230 would probably self-destruct in short order. In short I would swap engines (and completely upgrade the vehicle before) before I'd attempt to hot rod the 230 or 251.

There are mods that you can make that are easily reversible and will give some improvement in drivability such as electronic ignition and 4.89 gears but the they're expensive and the results are limited.

As far as the military water-proof ignition system, unless you do a LOT of driving it will probably costs you more for the civie parts than it will save you from buying military parts and the civie ignition system won't run any better than the military one. The Pertronix electronic ignition system might be a good investment. They don't run any better than a properly tuned stock system but it does stay in tune much longer. There are several threads on that subject already.

I have a very complete and very original '51 M-37 and I'd love more power and better drivablity but when I think of all the things that need to be changed (engine and transmission, add PS, add disc brakes, new master cylinder and brake booster, add alternator, add heat and air, improved lighting and signals, etc etc), it would be very expensive to do right and it would completely ruin the originality and collector value of my 37 so I'm just going to live with it as it is. For the money, I'd be a LOT better off just to buy an old M880, CUCV or even a deuce! However if I ever find an M-37 or a Power Wagon that's solid but has already been butchered then I intend to give it a go!

PS: The military constantly swapped engines in these (no, make that all their) vehicles so it's very unlikely that any of them still had the original engine in it when they were released by the military much less by the time that they got into civilian hands or now, 60 years later, so don't let the fact that the engine has been changed influence your decision about whether or not to modify it. The military changed engines like you or I would change tires!