Cummins re-power M41

[Dave Wigham]

Hello all, I'm UK based and own 1 of a very small handfull of the 5 tonners over here, so no help locally. I would like to upgrade my sick 465 to a Cummins which is readily available and easier to get parts for. So, which is the best Cummins to fit given that the truck will never run loaded again and what is involved, how's it done.
As much detail as poss. please. Like how do you mount the thing, does it bolt straight up to the original gearbox etc.

Cheers,

Dave Wigham.

 

[steelsoldiers]

Hi Dave, welcome to the forum! Please update your profile so that your signature shows your location. It makes it easier when responding to posts to know that you live accross the pond.

As for your engine swap question, there are several guys on the forum that have done a swap in a 2.5-ton, but I don't think anyone has a 5-ton with a Cummins. If it were me, I would look for a non-computer 8.3C. They are plentiful here and are pretty simple to maintain and hop-up. Probably the easiest thing IMO to do is find an 8.3 with the tranny included that way you aren't talking about adapting bellhousings, flywheels, clutches, etc... The stack tranny and t-case is divorced so you would just need to fab a new propshaft to hook the big-rig tranny to your t-case. I can't speak to engine mounts, but they shouldn't be too hard to fab.

Others are sure to chime in here. Good luck with your project!

 

[Dave Wigham]

Many thanks,

I'd figured a complete engine/geabox swap might be the way to do it. BUT the spag on the transfer box is worked by those air solinoids on the gearbox, some kind of sensor system to stop the transfer engauging when you slip into reverse. So I guess I'll have to build a manual system to manually tell the transfer box when I'm in forward or reverse.

Over here Cummins seem to have different names, we refer to the L10 or Cummins 250 etc. Is the 8.3c a 8.3 litre??

Cheers,

Dave.

PS. Not all that computer literate but I'll do what I can with my profile.

 

[Desert Rat]

Dave,

Yes it is. I'm a former trucker and truckers here state side also referr to those come-a-parts as an L10 or a 250. For over-the-road driving they're tiny engines over here. We jokingly refer to them as "In Need of Diapers" because they're so small. I used to have Cat 3406B 4&1/4s in my two semis I used to own, so an L10 is small. Perhaps in a M.A.N. they're the right size, I don't know. Some of the members here have never driven a semi so they use the litre displacement when talking about certain engines.

 

[Dave Wigham]

Many thanks for the reply.
The 5tonners that the US upgraded over here had the 250, but I see they had to lengthen the bonnet side flaps to fit the radiator in. The 250 in the 5 tonner is pretty awsum, given that the max we can run at is what we tare off at , ie about 9.5tonnes. (having said that the law is very vague and I tow my M35 and vice-versa.

The engines are plentiful both in big and little cam, my problem is

1. Where do I begin

2. How do I do it

To get a complete engine/gearbox assembly is no problem, but I still have to overcome the air solinoids on the original gearbox and the sump on the multifuel is cut out to go over the diff, and the M41 has the early power steering.

I might be better off trying to put a Cummins in the M35 as more people seem to have experience of that.... and then put one in the M41 when I've figured out what I'm actually doing.



All the best,

Dave.

PS in case you're wondering, my M41 was upgraded to multifuel by the US from a gas but there were so few M41s here in Europe that they escape the standard literature.

Thanks again.

 

[Desert Rat]

Dave,
Keep us posted. It sounds very interesting......

 

[hot rod deuce]

well i got a few cents for ya
The air selinoids may be overcome by just swaping in a full airshift case rather than the sprag... i assume they are like the M35 series only air operated sprag. that would also be a good upgrade. For the oil pump, many are reversable and i would look into heavy equipment rather than trucks for a motor as they often come in MANY differnt accesorie and pan configurations as opposed to the trucks that dont vary much. Also perhaps an N-14 if you would like something a little newer but electronic. thats just an upgraded "250" and all a "250" is is an 855 so if you like horsepower id go snag a 400 hp 855. they are fairly common in the heavy equipment line, id sell you one but your a little to far away. then if you get brave go dig up an 18 speed.
any if decide to go m35 let me know i have one