What modern engines would you choose?

meerkat · Post by **meerkat** » Sun Aug 24, 2008 4:40 pm

Man, I thought there was more to that story. Great stuff, thanks for those details!

k8icu · Post by **k8icu** » Sun Aug 24, 2008 6:27 pm

VROD02 wrote:The 37 was ment to be light on its feet.

Yep V as light as an elephant in tap shoes! LOL....All 8000 pounds of it...

Just to add to the conversation. The stock T245 is 606LBS dry weight. and the 4BT Cummins is around 750lbs wet weight. The 7.3L Powerchoke is 850lbs dry. I'm basing the weights on memory from recent web searches.

VROD02 · Post by **VROD02** » Sun Aug 24, 2008 7:46 pm

Show me a 4 ton M37 and I kiss you in a special place.

CGarbee · Post by **CGarbee** » Mon Aug 25, 2008 3:48 am

I've been running a Cummins 4BT backed by a ZF S5-42 transmission, 4.89 gears, Michelin 900r16 XZL's, four wheel disc brakes, and lockers front and rear, for years. Pretty much the same combination that I started with in the truck with the exception that I had a Ranger OD sandwiched between the engine and the stock NP88950 when I first did the conversion.

I get anywhere between 15-25mpg depending on loading, presence of cargo cover, and how hard I push it (acceleration and cruise speed).

When fully loaded, with a fully loaded M101A1 on the hitch, I have had a GVCW in the neighborhood of 12k lbs. Asside from taking longer to get up to speed, it is very well behaved with this loading. Considering that a M37 w/w is 5987lbs, add in a hundred extra for the engine trans combination (the ZF is lighter than the NP that was stock) and load it and the trailer to capactiy and it's easy to hit this loading...

Offroad, I've found that it is more capable than my stock truck. I tend to run most trails just above idle and use the torque to walk me over obstacles... I will admit that I run most trails in my area either empty or lightly loaded unless it is a trail maintenence weekend with the local 4x4 club...

I have a buddy who is installing a GM6.2 w/Spicer 3053A in a M37 in my yard currently. He will be running Michelin 1100r16 XZL's and four wheel discs. His choice of the engine/transmission combination came in large part due to the lower intial cost of the investment coupled with his intended use (interstate commute to the familly farm, light farm use, parades...)

I looked into using Detroit 3-53N, Hercules DT3.7, Perkins 4-236, GM6.x (I know folks who are running these in thier M37's) and some other engines such as those made by Deere and decided that the Cummins was the best option for me given my expected use of the truck. At the time I made the conversion, gas and diesel were right at $1/gallon and I figured that it would take about five years to pay off the investment compared to rebuilding the stock 230.

The truck is infinitely more usable with the repower.

I also have friends who have installed a Cummins 6AT, a Ford 300, a Chrysler slant 6, Chevy 350, Dodge 360, and one with a Chevy 396...

It all comes down to how you plan to use it, what skills you have (or purchase), and the depth of your pockets (including the decisions about intial cost versus running costs...).

Juan · Post by **Juan** » Mon Aug 25, 2008 5:01 am

CGarbee wrote:Offroad, I've found that it is more capable than my stock truck. I tend to run most trails just above idle and use the torque to walk me over obstacles...

The truck is infinitely more usable with the repower.

It all comes down to how you plan to use it, what skills you have (or purchase), and the depth of your pockets (including the decisions about intial cost versus running costs...).

Amen to all three Cabell's Statements, and I'm geting 22mpg at highway speeds.

k8icu · Post by **k8icu** » Mon Aug 25, 2008 7:04 am

Hey V I didn't pull the 8000 lbs out of my back side. That is from an Army manual. I believe it's a late 60s or early 70s -10 operators manual. The one with cartoon on the cover of the M37 looking like a bucking bronco. Anyway they have the cartoon Joe Dope type private holding an M37 like a new born and it says "It's your baby.... all 8000lbs of it."

Unfortunatly the manual is in PDF format so I don't know how I would post the picture on here.....but anyway...pucker up....

MSeriesRebuild · Post by **MSeriesRebuild** » Mon Aug 25, 2008 8:53 am

My M37 which has had the frame extended by 2' between the back of cab & the rear suspension & another 18" on the rear of the frame accomadates a 10' long 7'wide bed. On that bed is mounted an air compressor, & a tool box mounted on each side of the bed which are chocked full of tools, etc. My truck weighs 7,400lbs equipped as mentioned above. No way a stock M37 weighs 8,000lbs, I can't help what that book may say, what I'm saying is known fact.

CGarbee · Post by **CGarbee** » Mon Aug 25, 2008 9:13 am

MSeriesRebuild wrote: No way a stock M37 weighs 8,000lbs, I can't help what that book may say, what I'm saying is known fact.

My assumption (and we know what kind of trouble one get can get into with assumptions...) was that they were referring to the gross weight in that particular publication... Since the rest of the manuals and dataplates list the empty weight (wet) of the truck as being near 6K lbs, a ton of cargo would put one right at 8k lbs...

I figured that they were trying to impress upon an operator the mass that they would have to control going down the road.

k8icu · Post by **k8icu** » Mon Aug 25, 2008 2:06 pm

I think you are correct CG. The truck is only 6K but the army as always bumped it up to impart the importantance of the trucks weight with load.

Dang I wish I could post the picture...it's funny if for nothing else...

Still...the fact is the M37 light on it's feet is like an elephant in tap shoes. 1/4 tons were ment to be light on thier feet.

mattveeder · Post by **mattveeder** » Mon Aug 25, 2008 2:27 pm

I know that this is not an engine swap that I have heard anyone doing on this page. But if I was going to torture an m37 with a swap it would be an ford 5.0 fi engine out of an 88 to 95 mustang. Also I would use an t5 trans. 88 to 95 mustang setups use mass air instead of speed density to calibrate. So the mod possibility is endless. Next they are so common that tou can buy all parts from summit and jegs to include swap wire harness, computer and all sensors. Lastly the t5 is tough and has overdrive. So you can do this and use the stock transfer case. If you wanted to go real far out there an 4.6 4valve mustang engine and t56 6 speed. I personally know these engines real well but they can be very difficult cause of the electronic end of the swap. But they would be way more than you would ever need for the m37.

CGarbee · Post by **CGarbee** » Tue Aug 26, 2008 2:53 am

k8icu wrote:Dang I wish I could post the picture...it's funny if for nothing else...

I have no idea how to post them here, but the cartoon TM cover that you are talking about is located on my website at this URL:
http://www.garbee.net/~cabell/m37cartoon.htm

Enjoy.

uglyranger · Post by **uglyranger** » Tue Aug 26, 2008 4:27 am

Taken from your web site:

k8icu · Post by **k8icu** » Tue Aug 26, 2008 6:10 am

THAT'S IT!!!! See right there in black and white 8000 lbs... and we all know the Army never lies....

peter e mark · Post by **peter e mark** » Tue Aug 26, 2008 7:25 am

Well now , How about some comments from a reenactor. And I identify myself as such as an introduction to my viewpoint on these and all miulitary vehicles, which is: They exist to function, work , and otherwise perform...Now don't get exited Kieth, remember, I qualified these remarks as coming from a reenactors viewpoint. But as calmly pointed out in previous posts to this thread, we are all enjoying these vehicles in our own way. And now to my answer: I'll take a diesel please !

meerkat · Post by **meerkat** » Tue Aug 26, 2008 6:29 pm

Great answers, and a wide range of answers--thank you all for weighing in on this issue. So many of you mention swapping out the transmission as well....is that really necessary?