Aftermarket engine upgrades

[Chinookpilot77]

Hello all,

New to the site, but I've been around deuces for a long time. After lurking here for awhile, (and using search ) I have to ask the inevitable question: Why no aftermarket engine upgrades?

I think its disgusting that a 1400lb engine with almost 500ci displacement is only cranking out 130hp and 350 ft/lbs. Thats only marginally better than my wife's VW jetta!!!

When I first came here and started snooping around, I had no idea how such a horribly performing engine could even move a beast like the deuce...and then I saw the gear ratio of the axles and it clicked....

So, before I drop a 12v cummins in my truck, I thought I'd post here and ask what is stopping us from trying a new turbo or bigger injectors or both???!!! I have heard a few things about weak head gaskets, but thats the only thing so far.

Thanks a bunch for your time and great information on the site!

 

[cranetruck]

We love our multies.

 

[Boatcarpenter]

Amen Bjorn.
"nuff said.
BC

 

[clinto]

There have been a few threads about hot rodding the multi, I looked for them for a few minutes but had no luck, you might want to search a little more, as there was a lot of intelligent discussion about the limitations.

But in short, the head gasket issue, the strength of the blocks and reciprocating assy. are considered to be the limiting factors.

Plus, the drivetrain wasn't designed to take 300 hp. Once you upgrade the engine, you can expect other stuff to start to fail.

 

[beaubeau]

Multiful Deuce

DITO Boatcarpenter. Multifuel means just that, how nice it is to be able to use alternative fuels in this day. I have several Deuces and several 6bt's Cummins around and I could change power plants very easy, but it is not in the cards. On reliability, I have not seen a Blown Multifuel unless itwas misused by the operator, "Low oil, dirty oil, low or no water, and or modifying it to do what it was not ment to do. Phil

 

[Ferroequinologist]

I agree 110%. I would gladly give up some power and speed for the ability to pour almost any flammible liquid in the tank and get the heck out of dodge.

 

[mudguppy]

welcome 'pilot. i think that the majority of the feedback you will get here is what you've already recieved - not much help in the modding deptartment, purist mentality. even though you are in the correct forum for this kind of discussion, you probably won't see that much support but, rather, "live w/ it because that's what it came with" kind of advice.

the main limitation that i believe is the biggest design obstacle is the compression ratio - it's very high (22:1??) which is what allows it to run on alternative fuels. with such a high CR the headgasket is already under a lot of strain. that also tends to beat the snot out of the rotating assembly bearings and bushings. if that could be lowered down to 17-ish, i think you'd be able to add mucho more fuel and everything would be happier. the intake could also use a redesign to allow for easier air charge insertion. injectors could be modified by just about any performance injector shop. injection pump may be able to be turned up to hi-power levels, but i don't think it would be insanely difficult to adapt a different IP altogether (like a p-pump). turbo is the easy part.

the problem w/ the above plan is cost and demand for a number of reasons. first, as mentioned previously, most owners are happy w/ low power because it is oem - there's some kind of nastalgia with the many "reasons" that the deuce had low power levels.

second, engines are wicked cheap. the multi is the stock SBC of the medium duty world - everyone has one, reliable in stock trim, a million of them were made, so it's easier to just change one out instead of working on them.

third, old technology. a lot of work and R&D could be put into this engine, but the tech is 40 years old at best. there is no desire to turn a multi into a mod-friendly dt466 when there are already dt466's out there.

i have heard that there is a multi over 500hp used in a sled pulling application. but the person pushing that rumor had no substantial evidence (links, pics, etc). i'd still like to see it.

 

[mudguppy]

oh, also, i believe that the head is already studded. i would imagine that the stud size/material could be increased and clamping forces increased to hold the HG together longer, but i'm not sure that's been done yet.

 

[Ferroequinologist]

I wasn't merly saying I want to keep it stock, just like you said mudguppy, the time and modification required just isn't worth it to me personally. I would love to see what could be though.

 

[DUG]

I wonder how long until Rat4spd puts a Big Block Chevy in his?

 

[Stretch44875]

Couple of options. A LDS from a 5-ton is a higher horsepower version of the LDT, 180-200hp. LDS-465-2 is also a turned up Multi, not common, only used in ford 8x8's, 210hp.
Can also turn up the fuel on a LDT, and gain decent power. Best option for a LDT in my opinion would be a D turbo(reworked by jwaller or Ken), newest style headgaskets, and EGT's at 1200 pre-turbo. Should get you to 200hp, maybe a touch more.

Anything more may defeat the multi abilty of the motor, and at that point, plenty of civi engines can do the job better.

If ya just want to go fast, big block gas motor at 3500rpm, and with the multi transmission, would net you 78 mph on stock tires.

Dennis

 

[rat4spd]

That idea only lasts about as long as the realization that it'd get about 2 MPG

 

[mlwats1@hotmail.com]

and at that speed the red ring around your neck would be your hemroids, yikes

 

[Chinookpilot77]

Well thanks a bunch for all the feedback guys. I honestly hadn't given the multi ability much thought...I just thought these were kick ass trucks....but honestly once I sat here reading for several days (6 hours a day....my wife is thrilled! lol) I realized that I am going to want to do a body conversion of a 12valve dodge with a deuce body. I am NOT a purist. I want functionality and good looks.

Now, about the multi ability, I dont think you are giving low pressure diesels enough credit in that department. The aircraft I fly uses a TON of oil...(aft transmission holds 44 quarts) So, I can get VERY VERY clean used hydraulic and gear oil in LARGE quantities. A few friends of mine have run a 50/50 (w/ road diesel) blend of these in their 12v cummins and 7.3 fords...not an issue because the injectors are run at 30,000psi..(more like 12k I think) This oil is damn near brand new by automobile standards....but questionable for aviation purposes....you'd NEVER seen dirty oil in a helo...

So, even though I'm not leaving this forum, because I am learning a TON, I will not be getting a deuce after all, but quite soon I'll be in the market for 2 complete hardtop bodies, bumpers, etc etc!!!

If anyone wants to know about gas turbines, I can be of more use to you!

 

[Chinookpilot77]

Stretch44875

Hey bud, thanks for all the info, but I was looking at one of the 5 tons at work today and I dont think that monster would do well at all in the woods, even if I did put it in a deuce...that engine has to weigh 2000lbs!!!

I'll build up a mild 12valve (500hp lol) and put the deuce body on the dodge, that will fit my tastes nicely I think. Now if I could just get back to the states!!!!

 

[frodobaggins]

Well if you get it started/done post pics. I gotta see this.

 

[AceHigh]

(I hate riding in Chinooks) Welcome to the site!

 

[DUG]

That idea only lasts about as long as the realization that it'd get about 2 MPG

Not much less than the big block you sold me!

 

[Chinookpilot77]

Frodo,

I'm still in Germany, but as soon as I get back to good ole Ft. Rucker, Alabama, I'll be starting on this project. I figure I can do the quad cab up in the garage, drive the truck as-is until the cab is completely done...then the expensive parts start on the engine mods I have planned.

I did a little research for this already...the wheel base of a bobbed deuce should be 130inches. The wheel base of a dodge 1 ton is 139in. Thats gonna make one sweet quad cab with a super stubby box (which is just what i'm looking for)

 

[mudguppy]

i, personally, wouldn't go that route - i'd take the deuce, bob it, and drop in the 12v and tranny. mainly because dodge frames are questionable at best when it comes to taking a beating. the sheet metal itself (from the deuce) is quite heavy already, and you'll spend a lot of time mounting a cab from a straight frame truck to the curved dodge frame. you'll probably want to step the dodge axles up to the 2 1/2 tons anyway, because the unit-bearing dana 60 will be hating life w/ that weight and any larger tires. so by the time you go through all that adapting and fabbing you could've had the motors swapped and been driving!!

i definitely think that's the way to go - mainly because that's what i'm going to do...

you might as well pick up the deuce anyway, they're cheap. besides, you just might like it.