What modern engines would you choose?

meerkat · Post by **meerkat** » Sat Aug 23, 2008 5:51 am

Greetings all,

I'm in awe of your vehicles, and hope to get one of my own, one of these days. I realize my question violates the intent of restoration, but if each of you HAD TO replace the engine with a modern, off-the-shelf engine that given the proper mounts fit under the M37 hood, which engine would you choose?

And I apologize to any of you good folks my question might irritate.

best regards,
Meerkat

MSeriesRebuild · Post by **MSeriesRebuild** » Sat Aug 23, 2008 7:10 am

All things considered, longivity, ease of maintenance, fuel economy, etc., a Cummins diesel is a great option. Check out the photo/client pages on our website below

Lifer · Post by **Lifer** » Sat Aug 23, 2008 12:52 pm

I'll agree with Charles on this one, but the Dodge 318 that's in my '92 Dakota might be a viable option. A fully synchronized overdrive transmission would be another major improvement, as would a single-lever transfer case.

meerkat · Post by **meerkat** » Sat Aug 23, 2008 6:05 pm

Good answers gentlemen, and fast ones--thanks much. Outstanding website on your rebuilding works, MSR. I just spent twenty minutes daydreaming over there....

Has anyone reading this tried a Ford motor in an M37? How about a Unimog engine?

HOLZINGER · Post by **HOLZINGER** » Sat Aug 23, 2008 6:11 pm

There's a bored and stroked Dodge 340 in mine

Only modern if you consider 1972 modern

VROD02 · Post by **VROD02** » Sat Aug 23, 2008 6:17 pm

I totally disagree. Diesel's are cool in larger trucks. The weight of a diesel sucks, todays fuel prices plus the conversion and MAIN-TANANCE. The 37 was ment to be light on its feet. I would suggest a 4.3 gas v6 if you could waterproof it.Who here really puts 100K miles on a m37 to justify having a cummins?

I hear this more on the M715 zone, big issues with the stock 230 tornado.Gas is better with a toy, which most have.

MSeriesRebuild · Post by **MSeriesRebuild** » Sat Aug 23, 2008 6:39 pm

VROD02 wrote:I totally disagree. Diesel's are cool in larger trucks. The weight of a diesel sucks, todays fuel prices plus the conversion and MAIN-TANANCE. The 37 was ment to be light on its feet. I would suggest a 4.3 gas v6 if you could waterproof it.Who here really puts 100K miles on a m37 to justify having a cummins? I hear this more on the M715 zone, big issues with the stock 230 tornado.Gas is better with a toy, which most have.

Everyone is entitled to their own opinion & I respect yours, but for goodness sakes do your homework before commenting. A 4BTA Cummins like we use is less than 100lbs heavier than the stock 230, certainly not enough difference to be a weight issue. Neither does one have to have 100K mile expectations to reap the benefits of a diesel. With the 20+ MPG rated fuel economy with a 4BTA Cummins, that's much easier on the pocket book because of fewer stops at the pump. A gasser will get nowhere near that mileage & we haven't even discussed the benefits of exceptional torque the diesel offers, both low end off road & on highway, with way less maintenance than any gasser will require. With all due respect, you need to arrange a trip back to the drawing board.

VROD02 · Post by **VROD02** » Sat Aug 23, 2008 7:41 pm

MSeriesRebuild wrote:
VROD02 wrote:I totally disagree. Diesel's are cool in larger trucks. The weight of a diesel sucks, todays fuel prices plus the conversion and MAIN-TANANCE. The 37 was ment to be light on its feet. I would suggest a 4.3 gas v6 if you could waterproof it.Who here really puts 100K miles on a m37 to justify having a cummins? I hear this more on the M715 zone, big issues with the stock 230 tornado.Gas is better with a toy, which most have.
Everyone is entitled to their own opinion & I respect yours, but for goodness sakes do your homework before commenting. A 4BTA Cummins like we use is less than 100lbs heavier than the stock 230, certainly not enough difference to be a weight issue. Neither does one have to have 100K mile expectations to reap the benefits of a diesel. With the 20+ MPG rated fuel economy with a 4BTA Cummins, that's much easier on the pocket book because of fewer stops at the pump. A gasser will get nowhere near that mileage & we haven't even discussed the benefits of exceptional torque the diesel offers, both low end off road & on highway, with way less maintenance than any gasser will require. With all due respect, you need to arrange a trip back to the drawing board.

Well sir I respect yours as well and my math stands. 100 lbs. is about 1/3 more weight in the front, on 2 wheels. These trucks are 4x4's not 2 wheelers. Reaping the benifits of the conversion would take me the rest of my life at age 40. 20 + M.P.G. you've done more than an engine swap, and spring over. Why not just pop the body on a "new " rig.

The drawing board is simple on 1 tons and down. G.M. ,Ford or Dodge. a big block gasser is more powerful and weights less. I have a 502 chevy I dare anyone to try to out pull me with any of the big 3 diesels.But thats a work truck not a 4x4, collector, toy, ect. I respect your rigs I just differ in opinion and honestly I dont care for your tone, that nasty stinky rattle of your engine!

Tom @ Snake River · Post by **Tom @ Snake River** » Sat Aug 23, 2008 8:26 pm

What ever motor you chose. I would sure look at an automatic transmission with a married transfer case. Tom

uglyranger · Post by **uglyranger** » Sun Aug 24, 2008 2:01 am

I'm surprised that no one mentioned a small block Chevy V-8.

MSeriesRebuild · Post by **MSeriesRebuild** » Sun Aug 24, 2008 8:55 am

VROD02 wrote:
MSeriesRebuild wrote:
VROD02 wrote:I totally disagree. Diesel's are cool in larger trucks. The weight of a diesel sucks, todays fuel prices plus the conversion and MAIN-TANANCE. The 37 was ment to be light on its feet. I would suggest a 4.3 gas v6 if you could waterproof it.Who here really puts 100K miles on a m37 to justify having a cummins? I hear this more on the M715 zone, big issues with the stock 230 tornado.Gas is better with a toy, which most have.
Everyone is entitled to their own opinion & I respect yours, but for goodness sakes do your homework before commenting. A 4BTA Cummins like we use is less than 100lbs heavier than the stock 230, certainly not enough difference to be a weight issue. Neither does one have to have 100K mile expectations to reap the benefits of a diesel. With the 20+ MPG rated fuel economy with a 4BTA Cummins, that's much easier on the pocket book because of fewer stops at the pump. A gasser will get nowhere near that mileage & we haven't even discussed the benefits of exceptional torque the diesel offers, both low end off road & on highway, with way less maintenance than any gasser will require. With all due respect, you need to arrange a trip back to the drawing board.
Well sir I respect yours as well and my math stands. 100 lbs. is about 1/3 more weight in the front, on 2 wheels. These trucks are 4x4's not 2 wheelers. Reaping the benifits of the conversion would take me the rest of my life at age 40. 20 + M.P.G. you've done more than an engine swap, and spring over. Why not just pop the body on a "new " rig. The drawing board is simple on 1 tons and down. G.M. ,Ford or Dodge. a big block gasser is more powerful and weights less. I have a 502 chevy I dare anyone to try to out pull me with any of the big 3 diesels.But thats a work truck not a 4x4, collector, toy, ect. I respect your rigs I just differ in opinion and honestly I dont care for your tone, that nasty stinky rattle of your engine!

I believe I'm getting a clearer picture of why you prefer gassers. I've noticed over the years that the overwhelming majority of folks who have real problems with the "diesel rattle" or common diesel noise won't have one for that reason & that's just fine. I like quiet too, but having had vast diesel experience over many years, I distinctly realize the diesel benefit & don't let my love for quiet keep me from enjoying that. Our diesel powered M37 with nearly 200K miles on it, a 7'X10' flat bed, & weighing in at 7400lbs tare weight that is now our shop runner vehicle gets twice the mileage of my son's S10 chevy with its original 4 cylinder gasser. Twice the hauling space + twice the fuel mileage, me, I gotta love that. At today's fuel cost the noise it makes is no issue to me when figures like that factor into our bottom line.

Back to the noise issue, ours was built as a work truck when we did it, no consideration to noise was given any thought. Since we now build trucks for a living, we have included much noise filtering technology into our builds, depending on what the customer ask. Too many, the noise factor still isn't an issue, so we don't spend big $$$ in that area if they really don't care.

Juan · Post by **Juan** » Sun Aug 24, 2008 1:12 pm

uglyranger wrote:I'm surprised that no one mentioned a small block Chevy V-8.

That's the most cost effective engine swap if you are going to a gas v8, it's the cheapest conversion.
I'm a diesel guy when it comes to trucks, and I agree with Charles on this point, except I've chosen a GM 6.2L diesel for my conversions. (that he Hates

)
There's not a single thing, a stock M37 can do that a diesel converted (GM or Cummins) can't do it either, or improve it.
And the street ability of the diesel converted M37 is waaayyy better than a stock one.
You can't drive 100 highway miles every day in a stock M37 like I do with mine.

VROD02 · Post by **VROD02** » Sun Aug 24, 2008 1:15 pm

I hear ya Charles. No pun intended!

I respect your rigs very cool rides.You do great work. A point you did not bring up is ethinol SUCKS, breaks down in as little as 6 weeks, stabilizer manditory for non use. We could split the gasser debate in 2 with carb v.s. injection. These trucks are weekend warriors for me. So I'm not really a candidate for new tech. injection or diesel.I can work on a gas asperated engine. I feel the vast majority of owners of the m37's or m715 are in my boat as well. Majority want inexpensive fixes l. So I guess the real ? would be your intended use of the truck. Every day worker go with tech. Play toy stick with gas. Its funny the author of this post saw a debate coming. Once again I respect what you do with your trucks , just not my fit.

meerkat · Post by **meerkat** » Sun Aug 24, 2008 1:25 pm

Interesting answers! Juan, since you log so many miles with your vehicle, did you compile a list of all the engineers that could conceivably work? Do you remember what your other top choices were before you made your final selection?

Juan · Post by **Juan** » Sun Aug 24, 2008 2:45 pm

meerkat wrote:Interesting answers! Juan, since you log so many miles with your vehicle, did you compile a list of all the engineers that could conceivably work? Do you remember what your other top choices were before you made your final selection?

I did this conversion in '97. I needed a Diesel because gas was a lot more expensive here then. I knew I needed an OD tranny and a set of 4.89 gears for on road manners, wich implied disc brakes with power assist, and power steering. Of course modern bucket seats too.

I planned to use the truck as a toy for 4x4 adventures, wich I did until '05 when I got a promotion wich meant a job relocation 50 miles away from home. Wife needed the car everyday so the ol' toy has to deal with the daily commute since then.

Back then before I started the conversion I've considered the cummins way but a new 4b (no turbo) was around $9000 those days only for the engine. Then I still have to find the bellhousing, clutch assy, transmission etc.
Perkins diesels are plentifull down here but with a 2500 redline, I needed to swap tires for 1100-16, plus the OD tranny and 4.89 gears.
Deutz diesel are plentifull too down here but they are the noisiest and heavy diesels you can find.
Mercedes Benz had a tough 6 cyl. engine but it was too long and too heavy for the M-37.
Japanese diesels would have been fine but couldn't find a 4 liter engine those days, only 3 liters, that I've considered small for this application.
(Isuzu didn't bring their 4.3 and 4.8 4 cylinder engines in their cabovers, wich I think are great choces, until '00 down here)
One day I found Boyce Equipment had Army surplus 6.2 v8 engines for $1200 and they also had the 3053A transmissions and all what was needed to bolt them together.
Sold my truck (68 M37B1) bought a 51 from Vintage Power Wagons, bought the powertrain combo from Boyce, had it shipped to VPW, where they installed the powertrain (in a non functional way), shipped it to Miami and then to me. I also bought a brand new heater assy in it's crate that came in the back of the truck for $180 from them.
Once it arrived I discovered that the 6.2 was brand new, no use, but no wiring harness or alternators also. So I bought the cucv manuals and Boyce sold me a complete take out front/engine harness, both alternators, PS pump, Hydraboost brake assy, and all the brackets needed for puting it all together. Just needed to do the connections betweeen the oem harness and the engine. No big deal.