New member, new truck

[D'cheat]

It seems that I am getting a M139 gasser with in the next few weeks. The truck needs some work. Minor stuff really. By the way, it seems that I'm getting it for FREE!! I'm not about to tell you all where it is. Last thing I need is somebody telling the owner what he really has and offering him cash for it. *grin*
I have to thank all of you for running a Great resource on this site. I have been here every night for a few weeks now, finding out every thing about our trucks.
I have been involved in cars and trucks for a number of years. Building tube chassis rock crawlers, hot rodding what ever car I can get my hands on.
Now, there are a few things about our R6602's that I feel can be improved upon.
First, a big a$$ electric fan to free up HP and help with low RPM cooling.
Flex-a-lite Monster Fan #285. Pulls well over 5000cfm. A quick chat with tech support, and I learn that they can be converted to run on 24v by jumping two terminals on the controller!
Quick and easy!
Also, I'm starting to chat with Holley about adapting their 650cfm 4 bbl throttle body fuel injection kit. It seems that they may be able to! They say If I can lend them my truck for a few weeks, and have enough people interested, they will make a kit for US!
Problem is, how the hell can they dyno a 6x6. Pull the drive shaft from the rear, rear axle and also the front axle. Problem it, this will do funny things to the transfer case. Hmmm....


Anywho, if you feel that you would be interested in a fuel injection kit for a r6602 engine, sound off!
Be warned, it will cost in the range of $2,000... Ouch...


D"Cheat

 

[Monty]

FI might be the way to go but I would run individual injectors to each cylinder, the length of the intake could cause some problems with distribution. You could remove the pipe plugs from each cylinder on the intake and plumb them there. Otherwise the 6602 that I have runs fair, I heard that the Zenith carb is the way to go with these. I have only had my truck for 6 months but there are alot of people on this site who will help with questions.
The other thing that you'll want to do is get all the manuels that you can and read up on your truck.
Good luck with your project.
Chad

 

[acetomatoco]

I have three R6602 powered trucks here. They have sufficient power to do the job...and perform better than their M/F counterparts. I have used both the Holley and the Zenith...in fact, have 3 brandy new Zeniths and 4 takeoff Holleys here. My history with these trucks goes back to 1964 when I was in Germany with the USArmy Corps of Engineers building bridges across the Rhein, Main and Danube rivers. We had about 25 M139s (Which were almost brandy new). Only problems I remember were the spark plugs fouling from the rich jetting of the Holleys. The rule was to run them at 1000 RPM rather than the standard idle of 400 or so..when standing still. The problem was exacerbated by the Blue Crown Brand of spark plugs...they were just bad and would not fire after about one convoy.. we could not get the Champs or A/Ls at the time. There is no way in Hades I would put out any money to modify one of these wonderful old Chrome Moly engines with an electric fan or a fuel injection unit as they are wonderful the way they are in stock form. Having lasted 50 years without any upgrades and still starting on the coldest morning and not overheating pulling uphill in the hot summer. Keep them in tune and advance the timing a little because of the 87 octane gas being more than the MoGas they were designed to run and keep the valves adjusted and put in some lead substitute and they will last another 50 years.

I am stripping one of these trucks now, so if you need any of those 'little parts' let me know.

 

[DDoyle]

ACE has nailed this one on the head. IIRC, the weak part of this engine is the crank - so I dunno how much "hopping up" it will take. Also, in the early days there were problems with crankcase detonations on the 6602.

Regards,
David Doyle

 

[OD_Coyote]

Wow a free M139!!!! You cannot beat that!!!
I how you will post some pics of the truck when you pick it up.

 

[DMgunn]

D'cheat - Welcome. Try the truck as-is first. You'll be surprised at how long it can sit, and still start on the first revolution. Trying to get $2000 of benefit out of an EFI swap would take some time, not to mention you can replace the entire carb for $100 or so if it fails, but will need to diagnose, order, pay large $, wait, then wait longer while they produce a replacement part for your aftermarket setup. Assuming they did produce this kit, I will bet that in 10-15 years, every piece in it will be out of production and impossible to get. BUT, if you do try it, post up. You will have a captive audience of OD addicts watching.

ACE- It looks like you prefer the Zenith. Is this true? I've read in other threads that it runs generally leaner and more efficiently. I know this has been asked many times but not really answered definitively. Since you have experience with both, I would give your opinion more merit than those of us with only one. The core of the question is: I have a Holley on mine - is it worthwhile to swap to the Zenith? Cost and labor are not important to me.

 

[D'cheat]

Its not so much that I'm looking to hot rod this big'ol beast. Its more that I'm looking to update it and improve upon the 50's tech. The huge fan up front pulls 35hp away from the engine just above idle. I have read many a thread about our trucks over heating. In many ways, this is due to the low RPM's that the engine spins. With a high flow electric fan and or a aluminum radiator, this can be eliminated all together. The fan not only keeps you cool when your at a standstill, but it also frees up power and will greatly improve gas mileage.
Fuel injection. Why? There is nothing like a good computer keeping the perfect fuel mixture in your combustion chambers at all times. No more rejetting the carb when you head up to the hills. Spark plugs that last years, not months. No more worries about flooding the engine. And, improved gas mileage.
The long runners on the intake can be a problem. But if a standard carb. can do it, so can a throttle body system.
I also thought about propane. High octane fuel source. Very clean burning. Its already a gas when it enters then intake, so the long runners mean nothing there. Its self adjusting to altitude. Contrary to popular belief, it will not loose HP. Though there is one down side. You lose gas mileage. Approx 1 to 3 mpg according to what I have read. Bad enough getting 2 miles per gallon. Let alone 2 gallons per mile.

I know, it is best to leave that what is not broken alone. But come on fellas. Over 600ci of monster engine, that can be out perfomed in every way by a massaged small block v8?
There has to be something that is not allowing this engine to work at its top potential.


I have some fun plans for this truck. First, I have to cut the bed's width down. Overwide is a pain on the over crowded streets, let alone on a dirt trail on the hills.
The more I look at the bed, the more I think it will be cheaper to have a new one fabricated then spend weeks relocating all that steel with a plasma torch and a mig welder.
I'm going to remove the wheel spacers and go to super singles. (16x20 XL's of course)
I also want to increase the flexability of the suspension. Seeing that this truck will never see a full load of bridge components again, I'm going to remove a few of the leafs from the rear axle spring packs. Im also going to look at having a new set of leaf springs for the front made. In every picture I see of a 5 ton 6x6 flexing, the rear suspension is doing all the work while the front moves only a few inches. That is a simple enough fix.
I want to keep the truck a 6x6, but then again I also want to be able to turn around with a minimum of stop and back up's to make it. So, ill shorten the wheel base quite abit.

New canvas top, and some other minor stuff, and ill be quite happy

 

[gimpyrobb]

Man, thats an awfully good looking truck to cut up. It is yours and I can respect that. I don't want anyone telling me what I should do with my rig. Its going to be cool to see what mods you do. Keep posting pics, we love that.

 

[D'cheat]

Its a stunning truck. Every time I look at it, my heart skips a beat Not an ounce of rust. Not a dent in the body. Front bumper has been bent something fierce. No biggie there. Justs needs some tlc, fresh gas and batteries.
I will run it stock for a good while. Fix any little problems, then move on to the 'project' end of the build.
This poor thing has been sitting for 10 years. No paperwork, no nothing. The owner told me it came with the land when he bought it many a year ago. Its been pushed around alot to make room for equipment Never been started.
Thats why the great deal. He just wants it out of his property. Thats where I come in

 

[DMgunn]

Wow. Looks like its in nice shape! Got any side views?

I see your points about the engine mods, but find me a small block that makes as much torque as the 602 - AND will last for 50 years.......... yeah.

 

[D'cheat]

There was too much large equipment next to it for me to get a side shot. As you know, you have to step WAY back to do that

*chuckles* Great point about the small block DMgunn!

 

[DMgunn]

Another thought to consider. Couple guys on SS have been craving XLWB 5-tons for awhile. This one is so nice, it really would be a shame to see it "cut up". Perhaps you could pull off a trade for a 5-ton tractor....wheelbase would already be short (big labor saver there), overwidth would not be an issue (wouldn't have to remove spacers, change studs, rear axles, etc.), and someone would get a great head start on a bridge truck restoration. Then all you'd have to do is pull the plate, and mount up a bed.

 

[D'cheat]

Re: RE: New member, new truck

I am stripping one of these trucks now, so if you need any of those 'little parts' let me know.

Any chance of having a left windshield, and left/right windshield wipers/motors?


*grin*

 

[D'cheat]

Another thought to consider. Couple guys on SS have been craving XLWB 5-tons for awhile. This one is so nice, it really would be a shame to see it "cut up". Perhaps you could pull off a trade for a 5-ton tractor....wheelbase would already be short (big labor saver there), overwidth would not be an issue (wouldn't have to remove spacers, change studs, rear axles, etc.), and someone would get a great head start on a bridge truck restoration. Then all you'd have to do is pull the plate, and mount up a bed.

I had thought about that. But, this rig as no title/paperwork. No interoir *like there was any to begin with* and as of yet is not running. *Needs fluid changes, fuel system flush, new batteries etc... Basic stuff*
Unless said person is near Nevada, its kinda a hard deal for a runnning tractor. A tractor is what i need, however I have never even seen a 5tonner on the streets here in Reno..

I would love to leave it stock. But it just wont work for my application like that.

 

[DMgunn]

I can understand that. I am in the same boat. Love 5-tons but ideally want a shorter WB. Well, I own the only 5-ton I have ever seen in person, so I will have to build it into what I want. Only mine isn't nearly as nice as yours, so I don't have any guilt to overcome, just ALOT of work. But at least its fun work, and I don't have to work on it when I don't want to.

I actually prefer the width of these trucks, so I don't consider that a negative. BTW, if you plan to drive it that way for awhile, check into annual overwidth permits. They have them in both ND ($500/yr) and SD ($60/yr). Could save you a big headache...

 

[D'cheat]

Gotta love nevada. No humidity, no rain and no salt on the roads. Nothing rusts over here.
I like building stuff. Im dreading the bed part of the project, but relocating the axles seems to be a snap.
Previous projects:
1985 ford bronco II, Boss 302 v8, c4 automatic, f350 axles and 38" tires
1971 chevy c10 stepside. 700hp.
1992 Subaru SVX. Custom suspension, turbo, near 500hp and top speed of 160+
1992 Chevy Blazer, fullsize. 454 v8, th400 transmission, dana 60 front and 14bolt rear axle. 40" tires.
Countless friends trucks, chassis and cars
2006 Mazda 3 hatchback. Started to make it rear engine and rear wheel drive but I got smashed into by a fella with no insurance.

*chuckles* Like I said. I like to build stuff. Have title, will modify.

 

[m139h2otruck]

Having worked on these trucks for the last 2 years, the most important thing I can warn you about is the size and weight of the various components! The rear hubs w/ brake drums take two men to remove and replace without a crane. The engines weigh over 2,000# w/o the transmissions and the transfer case (our next problem) has to weigh at least 800# and needs the truck to be jacked up if removed from the bottom.

We thought about cutting the spare M139 down to a 4x4 with gas power, but after looking things over, one of the other shorter trucks would be a lot easier. Not trying to be a sour apple, just be careful and forewarned.

 

[OD_Coyote]

Man, thats an awfully good looking truck to cut up. It is yours and I can respect that. I don't want anyone telling me what I should do with my rig. Its going to be cool to see what mods you do. Keep posting pics, we love that.

That truck looks likes like a good candidate for restoration. I sure wish I could find a truck like that in my area. Thanks for posting the picture and good luck with the truck.

 

[Recovry4x4]

I hear what you are saying about the comparo with the HP of a small block but these things have gobs of torque. At just above an idle, you can drag a pulling tractor sled to Rhode Island with the thing. I'm not a gasser fan and repower everything gas I get but that R6602 would be the one exception for me.

 

[pa.rich]

You got that for free?!!! There is the drool again. I know why I keep tissues at the computer.Slurp slurp.