Big cam III in a 5ton?

[Grease4peace]

I'm sure this is an old idea but I'm new here. Does anybody have a 5 ton with a Cummins Big Cam III in it? Does that swap work with all off the class IX shelf parts? How do they do in a M813 or M923? What tranny is needed? What kind of highway speed do they get with 14.00 tires? I can't stop my curiosity on this one.

 

[WillWagner]

It has been kicked around a few times, the latest a week ago maybe. I know there are pictures here somewhere too. Try the search feature and see what you come up with

 

[wreckerman893]

There was a recent post from someone that bought a 400 Cummmins from GL. It was new and was for the M915 road tractor.
I would think that it would be a fairly simple bolt in if the demsions are the same as the 250 and all the plumbing would hook up.
I plan to try to find one to put in my newly acquired 5 ton wrecker.
Never underestimate the power of a redneck with power tools and a welder.

 

[timntrucks]

i have a welder..... redneck road crew comes to mind ....

 

[jwaller]

I like the idea of going with a big cam III and have access to one that just been rebuilt. but the cost of a motor like that can quickly exceed the price of the truck which doesn't take much since. so I have rethought my plan and am going to modify the 250 till it blows it's top. if at that point I don't have enough power I'll swap motors. the III should fit directly with the same trans and same road speed as they too are limited to 2100rpms if I remember right. so your not going to go any faster but you will be able to maintain tops speed instead of losing it all on the hills.

 

[wreckerman893]

J,

One of the guys at work is a "diesel doctor" and I asked him about maxing out the 250 with a turbo, bigger injuctors, another cam, etc.
He said said cost wise you would be better off to do the swap unless you can do all the work yourself and have access to a machine shop..

Wrecker

 

[DaveP]

I dont think it's worth going thru all the hassles and $$ when our little 250's do not have the piston coolers. I have bumped my XM818 a bit and unless its below 0 ambeient temp its real easy to hit 1,200 on the exhaust. maybe an intercooler would help keep the temp down.

 

[jwaller]

J,

One of the guys at work is a "diesel doctor" and I asked him about maxing out the 250 with a turbo, bigger injuctors, another cam, etc.
He said said cost wise you would be better off to do the swap unless you can do all the work yourself and have access to a machine shop..

Wrecker

I'm not going into the motor everything I'm going to do will be external and yes I do all my own work as I guess most on here do.

as I did with the deuce I'm prob going to use water injection to keep the IAT's down and thus egt's. I'm not going to try and make a 250 into a 400. more like a 250 into a 325 or so. 400 turbo, injectors, intercooler, WI, and low boost should do the trick. Should be easy for me. as I'm pretty capable when it comes to turning a wrench. just take a look at my site if need be.

 

[bobbytoday]

engine swap questions

I have a m813 I would like to make the swap to get more power and change the 250 for the biggest strongest turbocharge engine I can put in that will still fit the mounts in the m813.

My mechanic doesnt want to do the project unless he knows of someone that did it and
had good reults.

are there any special parts that need to be fabricated?

I live in southern cal and I was wonder where is the best place to have this done.

also, what is the way I can max out the ntc400 to get even more hp out of it?

what is the best model of the engine to get to maximize performance?

Thanxs Guys!

 

[M1075]

RE: engine swap questions

What application do you plan on using your M813 for? A different truck might suit your needs better and already be equipped with sufficient power.

 

[No.2Diesel]

RE: engine swap questions

Bobbytoday: See my post: "M819 RECEIVES NTC400!!" (I don't know how to link threads.)

Everyone else: Expect an update on this in I'd say 2 weeks or so I promise... I'm still in the process of putting in a "nicer" driveway and motorpool parking & maintenance area so the swap can take place without constantly standing in the mud.

Jwaller said:

they too are limited to 2100rpms if I remember right. so your not going to go any faster but you will be able to maintain tops speed instead of losing it all on the hills.

That pretty much sums it up.

 

[bobbytoday]

RE: engine swap questions

Thanxs Guys!

I pull an econoline trailer with weasel in it and lots of other stuff in bed of m813 and I have the big super singles 16"wide so I have been getting up to 65mph dowwn hills but I would love to go 65 mph up the hills. Also we camp in the glamis sand dunes and want to have enough power to drive around in the sand dunes.

 

[bobbytoday]

RE: engine swap questions

another stupid question from me is there a way to increase the limit on the governer to let the rpms go higher?

with regard to the different big cam ntc400 engines is any particular one higher performance than the other?

are there any shops that can build a suped up ntc400 with even more hp? I dodnt care abt fuel economy I just want performance for this particular truck!

 

[Boatcarpenter]

RE: engine swap questions

Hey bobbytoday, we need a location, forum rule
BC

 

[DDoyle]

RE: engine swap questions

Keep in mind that by design, the weak link in these trucks is the engine. In combat or tactical situations, it is far better to stall the engine than it is to snap a u-joint. Also, the trucks were designed for something over 70 percent of their lives to be off-road....and that is the military's idea of road (which doesn't involve pavement). Virtually no one on this board uses the trucks as they were designed to be used. This poster did not, but others have remarked "these trucks are underpowered" - when that simply is not true, those folks just don't understand the design criteria.

Hence, be aware that by increasing horsepower/RPMs you run the real risk of breaking something else if you venture off road.

Best wishes,
David Doyle

 

[emr]

RE: engine swap questions

David, Thank You very much for that info that these trucks are not under powered just not being used for whats intended use is/was... I always cringe with that slogan..under powered, Ive 4 byed alot with my trucks and they are awesome, along with the famous NDT's got me stuck they stink line...I LOVE NDT's ...that gets a hoot out of me every time, Driver error in a wide array of ways is the biggest problem these trucks have today and im sure in the past. Now as for the guy who hotrods there stuff thats cool too. I always dream of the super deuce or 800 series, But it takes an aweful lot more than a motor to make these trucks perform and still be safe to others on the road,and... not be break down queens, they are just not over the road trucks, as for Bobby He is in a 90 percent off road persuit, just travels to and from the sand, I see the need and as long as one remembers when the drive train is falling apart it is important to remember its not the trucks fault.these are not 65 mile per hour trucks and expecially with those super off road tires, once they break loose from the road there will be NO turning back, it will be a mess when the first guy loses it on an interstate doing 65 plus..my 2 and a half cents...Randy

 

[73m819]

RE: engine swap questions

remember that not only that most of our trucks are not a over the road design but have late 40s / early 50s brakes designed for 50 mph stopping at best,, just my 2 cents

 

[beaubeau]

RE: engine swap questions

I don't know if these 250 Cummins are the same as what I drove in a Commercial TT, but for about 10 years we had a White 4000 with 250 Cummins pulling 45ft trls ronning average 80,000 lbs. Running a 10sp Road Ranger, it did the job OK! Just a little slower than the International 4200 with 903 V8 Cummuns, 10 spd RR that I drove. Nice quiet cab and lots of Bark from the 903!!
I believe I got Hi bid on an 818 today, so I shall find out what these trucks are really like. I drove 5 ton tractors with multifuels when I was in Nam. I am sure the Cummins is a mite Different!! Yes I agree with the fact that these trucks are built for Off Road and are limited to what can be done wiyh them as far as speed and power are concerned.
Good luck all, Phil

 

[jd-ford-hd]

Re: RE: engine swap questions

another stupid question from me is there a way to increase the limit on the governer to let the rpms go higher?

Hey bobbytoday, Increasing RPM is a definite no no. This engine is 855 cu in , 5" bore, 6" stroke. Lots of big heavy parts changing direction inside your motor at an unbelievable rate. These motors will live forever at 2100. Lay a rock on the throttle and walk away, it will still be in one piece when the tank runs dry. Truck diesels are more often than not "blown" by drivers letting the RPMs get to high on down hill runs. Good Luck.

 

[menofiron]

RE: Re: RE: engine swap questions

In a farm tractor they spin a 855 cummins to 2400 rpm.