1951 M37 4bt Modern Repower

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JeffTheMarine
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Re: 1951 M37 4bt Modern Repower

Post by JeffTheMarine »

T. Highway wrote:Jeff,

Please explain it to your wife this way. It is semi-official Marine Corps policy "to go shopping whenever we were around another branches service gear" so actually you are still following SOP. Just remember to put a handle on the front of the hood, paper clips on the front bumper, change out the dash ID plates, get a pair of rear airlift brackets (from Storm here on the forum) and paint on the USMC markings.

Bert

HA! You know that reminds me of a very specific story that I read about a battle during the Korean war where the Army was ambushed and retreated and left all of their trucks behind. The Marines then came in and fought them off and ended up taking all of the left behind vehicles and equipment and painted them up in Marine markings. Afterward the Army general went to the Marine general and said he wanted his trucks back and the Marine general told him they didn't have anything belonging to the Army that everything they had was marked with Marine markings and obviously wasn't the Armys.

Jeff
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Re: 1951 M37 4bt Modern Repower

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neverfinished wrote:Hi Jeff, I never found any original markings on that truck-whoever painted it did an unusually good job of prep it seems. I don't recall seeing anything but the typical green paint under the yellow, but you'll know for sure when you sand on the cab and doors. Also, it didn't have any of the usual Marine extras. Can't wait to see what you make of it.
Ted
Well I suppose that I can just mark it up with the Marine corps stuff and call it a day. No worries either way. I am pretty excited. We just purchased a new system at work that does spray on liners and I really like the quality of it so I am going to be able to spray my bed here soon for only the cost of materials. Always a plus to have some kind of connections. The truck is going to be original in no way so I suppose it's not that important if it originally was. In that same sense it didn't have any of the data tags on it or with it when I purchased it so that also doesn't make that big of a difference either.


Does anyone have any information if I could run the factory LU4 winch with aftermarket setup? I am going to be running a NV4500 trans and a NP205 transfer case so I don't see why I couldn't just run the PTO off of the drivers side of the transmission to the winch? If so then I suppose that I could run a factory winch then. Info would be appreciated though.

Thanks
Jeff
chris olson
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Re: 1951 M37 4bt Modern Repower

Post by chris olson »

I like that story about the Marines repainting the abandoned army trucks.....
I guess the answer to what makes it a Marine corps truck...Because a Marine painted it and he says so.
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JimC
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Re: 1951 M37 4bt Modern Repower

Post by JimC »

Jeff, I don't see any reason why the LU-4 would be a problem.
I run an LU-4 in my 37 with a big block Chevy and an SM465 transmission. You just have to position the transmission so the jackshaft lines up with the stock frame holes.
topellis
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Re: 1951 M37 4bt Modern Repower

Post by topellis »

Hey Jeff,
My truck was an Army truck when I purchased it and I actually purchased a B-1 truck to get the front bumper off of it and the rear lifting shackles off of it to put on my truck. I just swapped the front bumper and robbed the shackles off the back and resold the truck. I think I actually got a little more out of it than I paid so it worked out well for me. Mine originally had the stars but I did them in when I repainted. I retired form the Corps in 2007 and I did keep the pics of how it was originally but I hope to have it a good long time and while I own it.... it will be a historically incorrect "Marine Truck". Most of our radio gear we had when I first joined was Army hand-me-down stuff... Mutts too.

Good luck with your project, I wish I had the cash to do the 4bt but that will have to wait a few years.
Good to see your pictures, take more and post them when you can.
Mark Ellis
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1967 M101A1
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JimC
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Re: 1951 M37 4bt Modern Repower

Post by JimC »

Why is the 4bt such a popular repower?
4bt weight 745 - 782 pounds
4bt torque 265 foot-pounds
vs
bb chevy weight 520 - 570 pounds
bb chevy torque 500 - 600 foot-pounds

It seems to me that the bb chevy might save a couple hundred pounds and give twice the torque.
JeffTheMarine
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Re: 1951 M37 4bt Modern Repower

Post by JeffTheMarine »

JimC wrote:Why is the 4bt such a popular repower?
4bt weight 745 - 782 pounds
4bt torque 265 foot-pounds
vs
bb chevy weight 520 - 570 pounds
bb chevy torque 500 - 600 foot-pounds

It seems to me that the bb chevy might save a couple hundred pounds and give twice the torque.
Well for several reasons. To begin with that is only the stock numbers for the 4bt. The mechanical injection pumps on these engines can be "tuned" to obtain more power without having to spend a single penny. Of course you can spend money on parts and a lot of people do. With the simple modification to the engine that I plan I will easily have nearly 500ftlbs of torque. Yes the weight of the engine is something that can not really be worked around; however the weight means that it is built stronger to withstand the diesel combustion cycle. This leads to longevity. I had a 1990 6bt Dodge that was nearly at a half million miles before I sold it and it was still running and pulled strong. The other major benefit is that the fuel mileage of the 4bt will far surpass that of the BBC. On average I am seeing that most people report mid to high 20's. I don't know what a BBC averages but I guarantee it's nowhere close to that. Along those same lines diesel engines make all their torque nearly off idle so for any type of off roading you would have all the torque you would ever need at a very low RPM.


Jeff
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Re: 1951 M37 4bt Modern Repower

Post by JimC »

Thanks for the info.
In my 37, the bb Chevy with stock 5.83 gearing gets 11 mpg average. It makes up for that by being fairly perky.
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Re: 1951 M37 4bt Modern Repower

Post by m-37Bruce »

Well Jim, there is perky and sensible, torque is torque!
Bruce,

1953 M-37 w/ow

Retired Again

Keep Em Rollin'

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Re: 1951 M37 4bt Modern Repower

Post by JimC »

I would sure agree with that, but I've gotten decent performance out of the BBC in the 45 years since I installed it. I've had the BBC up to a little over 111 mph. That's what I meant by perky. Will the 4bt do that with stock gearing?
:-)
P.S. No mention of sensible.
P.P.S. 111 mph in an M37 is entertaining, but not much fun.
Last edited by JimC on Fri Oct 03, 2014 7:35 pm, edited 1 time in total.
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Re: 1951 M37 4bt Modern Repower

Post by Master Yota »

A 4bt is used simply because the builder wants one. There is no $$$ gain to installing one. The mileage is irrelevant. If the 4bt averages 20 mpg, and the BB averages 11mpg, then we are talking a mileage savings, or difference of 9mpg. Whatever money that 9mpg may save is lost at every service, and the overall cost of replacement parts. Factor that against the initial investment cost of almost 4:1 over the gasser, and the fact that diesel fuel is usually more expensive than gasoline, and any implied savings are out the window.

Any newer LS engine will easily match the 4bt for output, and deliver similar economy, stock or otherwise...

I did the math once, and it worked out to something like 250 tanks of fuel, or 125000 miles before the diesel breaks even and starts to pay for itself. And thats not accounting for the ever climbing cost of diesel fuel...

I went with the BBF for the same reason that Jim did. Its cost effective and fun. :mrgreen:
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Re: 1951 M37 4bt Modern Repower

Post by JimC »

+1, Ray.
Back when I installed the bbc, diesel was a lot cheaper than gas, but I installed the gasser anyway. I wanted the ability to turn 6500 rpm (again, no mention of sensible - but a lot of fun).
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Re: 1951 M37 4bt Modern Repower

Post by Master Yota »

Diesels gained a reputation (deservedly) in the 1980's as fuel-mizers. The old GM 6.2 and the 5.9 Cummins 12 valve would turn out 30mpg, with a 4spd non overdrive transmission, and tall differential gears, usually around 3.08:1 or 3.30:1. But all they were good for was mileage, most of them wouldn't pull a fat kid off a smartie, compared to towing with a big block gas engine, they were not considered competition. But for those who towed occasionally, and could live with towing speeds that were slower than the second comming, the mileage was nice the rest of the time the truck was empty, if you could live with something that accelerated like a lawn tractor. The best gas engines of the era only averaged about 14mpg so the attraction to 30mpg was obvious.

Fast forward some 30 years, and the big 3 diesels all offer earth moving performance, but at the cost of economy. None of the current diesels get great mileage, averaging about 14-16 mpg while towing, and about 20ish when empty. That mileage matches the 6.0L LS engine in my 2500, as gas engines have improved to such a degree that the determining factor is no longer fuel economy, but initial cost.

Now don't get me wrong, I'd probably own/or build an M with a 4bt in it if it was practical to do in my neck of the woods, after all it is a great diesel engine when compared to other diesel choices for an M37. Its just not for me.

But I'll still enjoy the pictures of the engine swap when they are posted... :lol:
Ray
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Re: 1951 M37 4bt Modern Repower

Post by JimC »

When I had the Dodge 318 in my 37 (mid-60's), it got about 13 mpg (but wasn't perky).
JeffTheMarine
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Re: 1951 M37 4bt Modern Repower

Post by JeffTheMarine »

Well specifically for my build I am using the 4BT because well

1- I am a huge fan of Cummins Diesels,
2-Out of all of the diesel options for the M37 I don't see how anyone would go any other way.
3-When the SHTF I know I can run any of my Cummins engines on the engine oil straight out of the oil pan of any car on the road

4-THIS IS AMERICA AND I CAN!

Also I just got the heater that I am going to use for my truck in the mail yesterday so pictures will soon follow of the disassembled pieces and the finished product. I am going to be running an older Mopar Truck Master 61 in my truck.

This is all

Jeff
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