Re-Power from continental 6602 to diesel

[mightyhammer]

Anyone done or heard of repowering an older 5 ton with a newer diesel of any type? I have a 1954 bridge truck with a 6602 in it and was wondering if anyone here has done a diesel re-power on one of these older trucks.

 

[mightyhammer]

Is the tranny in the older 5 tons an overdrive? What about length dims and mounting areas? I have seen and heard alot about the swaps, but haven't seen any actual pictures of member swaps done.

 

[gimpyrobb]

My M62 was originally a gasser. I was updated by uncle sam in 89 and now sports a multifuel. Glad it has it too, I can run on cheap fuel now. Dunno about the trans.

 

[vtdeucedriver]

WOW, been so long since I have been in my M62 that I dont remember where 5th gear is. Easiest way to tell, 5th is up foreward like the deuce shift patern. The direct drive trans its back to the right. I really had to think about shifting when I would switch from the M35 to the M52.

 

[m139h2otruck]

Gassers and multis both used the non-OD 5 speed (2600-2900 rpm redline). The 800s and the Mack engined trucks used the OD 5 speed (2100-2200 rpm redline). A Mack or a multi will bolt in to a gasser if you use the correct front cross member, and cut the frame rail on the right side for the Mack.

I think a better choice on newer engines would be the Cummins 8.3 engine, but not sure about length. Horsepower would be anywhere between 210 to 300+, with a lot less weight.

 

[m139h2otruck]

Also, have to add, that the bridge trucks are over-width if you use the original flat bed and dual 1400x20 tires on the rear axles.

 

[mightyhammer]

Thanks for the info... I knew about the overwidth. I am making a self loading stud truck out of it since the frame is so long. The quandry I am dealing with is if I should repower with what fits easy....or.... I am actually considering upgrading to a 400BC Cummins with a RTO 14513. I have the tranny already in my shop...I have connections for the Cummins. My only thing is how much rearward moving of the transfer case and cross-members, shortening drive-shafts etc... I am not worried about the front to much(except for pushing the winch out more), as I can make one of the longer hoods work for the extra length forward for the radiator and all that.
NO.2 diesel is doing a similar upgrade and I am waiting to see how his goes before I dive into mine...
Sure would like the extra power from the 400, but I am not sure if worth all the work when I could just bolt a 465 in. Is there anyway to get 300 ponies+ torque out of a 465 without frying it? I haven't seen much about making big power output on the LDS-465 engines. I imagine bigger injectors, turn up pump, bigger turbo, air to air...the regular stuff. Any Ideas??? COOP

 

[DDoyle]

the elongated nose of the 800 series was specifically designed because the Cummins would not fit under the gasser hood. The 6602 has plenty of torque, BTW.

 

[mightyhammer]

Yessir, that would be the hood I would use if I did the cummins swap. Just a matter of moving everything else forward some.

 

[mightyhammer]

Yea....I know you can drive over trees with the 6602 because of its torqueiness....Only problem is the 2mpg it gets.

 

[DDoyle]

Yea....I know you can drive over trees with the 6602 because of its torqueiness....Only problem is the 2mpg it gets.

Tell me about it.....

 

[vtdeucedriver]

Tell me about it.....

Supposidly if you take off the Holly carb and put on the redesigned replacement carb that it could possibly get 4mpg.

 

[Monty]

I read someone swapping to a Zenith carb and getting alot better performance out of the 6602.
Saturn has then on their website for 125.00, might be worth a try.

 

[m139h2otruck]

We have the Zenith carb on ours, and it runs much cleaner than the original Holley. The only problem is parts!!! Have not been able to find anything for parts, gaskets, needles, diaphragms, etc. Gov. diaphragm was no good almost from the start, and we took a Holley apart and re-used its gov. diaphragm to set the redline @ 2900-3000 rpm. Have roughly checked milage, and with the water tank more or less empty, its about 3 mpg. But, it will go 55-60 mph no problem on the level and over 65 mph on a slight down grade!!

Anyone know where to get Zenith parts??

 

[DDoyle]

My M62 has the Zenith, and gets about 2 MPG.

 

[Monty]

My M62 has the Zenith, and gets about 2 MPG.

OH BOY I guess it's a good thing that the price of gas has went down.

So is the bad MPG because of the weight of the truck ( you have to keep your foot into it to get it up to speed and hold it there).

Under powered for the weight of the truck so ...(see above).

Or ???

I guess what I'm wondering is if the carb could be swapped for a more modern one ( Holley etc) and would it run better? Or just swap it out for a multi??

Opinons

 

[vtdeucedriver]

Mine runs great and its really too bad but hopefully in the spring I will pick up a engine that will be given to me. Mine will eventually have a ENDT-673.

 

[desertfox]

Since it is a 1954 probably not a 5 speed overdrive. Even some 60s era trucks did not have the OD. My M51A2 Jeep-Kaiser does not have the OD. Top speed is about 45 and smokes like a chimney even with a turbo.

 

[BEASTMASTER]

Nah they ain't that bad . I get 5 mpg bopping around town. Less when i'm plowing though. If you retranny it , how are you going to get the sprag to work for the front end ??

 

[DDoyle]

The trucks originally had Holleys on them, the military went to the Zenith. Engine design dates back to the 1940s, maybe earlier, I've not looked. Wrecker tips the scales at about 33000 lbs, bridge truck about the same (most folks don't understand just how substantial that bridge bed is) - either a bit heavier than cargo trucks.

And, as stated elsewhere, the trucks were not designed for the kind of driving we do...."up to speed" was not a real operational military concern. In the 15-25 MPH or so range that it was expected most of the operation of these trucks would be operated in, you can not only pull the house, you can pull the entire neighborhood......so not really underpowered.

None of the gas powered 5 tons had overdrive transmissions - if there was one in my wrecker I suspect you'd have to come out of overdrive for ANY grade.

Regards,
David

OH BOY I guess it's a good thing that the price of gas has went down.

So is the bad MPG because of the weight of the truck ( you have to keep your foot into it to get it up to speed and hold it there).

Under powered for the weight of the truck so ...(see above).

Or ???

I guess what I'm wondering is if the carb could be swapped for a more modern one ( Holley etc) and would it run better? Or just swap it out for a multi??

Opinons