Re: An old man's journey with GMC 702 V12s
 

Jolly:
That tank was out of another pickup. Back in the days when propane was the cheapest fuel of choice in farm machinery and pickups around here, about every pickup had a tank that size in the back. The tanks are designed with "wet" valves in them so liquid propane could be transfered to other tanks.
I do need to get the valve guard bolted back on it, tho. Should have done that before posting pic.

Mid-60s, I had a '62 Ford 1/2 ton/w a I6 on propane for farm use. I had a tank about that size in it, and could go about a 900 mi. on a tank. We could get a Flat Fee Farm users permit sticker for a year, then could use farm fuel in them/w no Okla. road tax. Had to turn in a mileage report each year. Farm propane was $.07 cents a gallon. We had to pay Fed. road use tax, tho.
By the mid-70s, diesel had pretty well become king.
Anymore, having propane on these V12s, the propane is about as much a novelty as the motor, which the irrigation motors were built for propane or Natural gas.
I check all the valves and fittings pretty often with soap for leaks. I feel safer with propane than gasoline. I used to work for a propane distributor in Mo., drove their 9,000gal transport to and from the refinery some, as well as house to house with a 2,400 gal tank truck. They schooled us all pretty good on all the do's and don'ts.

Re: An old man's journey with GMC 702 V12s
 

I haven't had anything much of interest to post for awhile. I never even took "Thumper" to any little local shows this summer. Just enjoyed little neighborhood rides within 10mi. of the house. About decided that most of the bugs has been worked out. Still much wiring left, mostly lights, but do have turn signals, thanks to Rap-em-papy. Runs and drives great up to it's 73mph @ 2400rpm max. Get lots of thumps-up when people pass.

However it's been interesting to hear local comments, or some friends and relatives who have come to visit us.
The locals will look at it as if it should be out in the junkpiles with most of all the V12s that once was used here. They act as if it's foolishness to still have one running and in a old junky truck. BUT, then they proceed to tell me of a V12 someone had and how durable it was, and how long it was run.
On the other hand, those from out of the area, will look at it with a sort of amazement that such a critter was built, and the uniqueness of the engineering.

We went out to Cimarron Heritage museum and moved the '62 GMC ton into her new building last month. The curator told us it's still a popular exhibit there.
That within itself makes the preservation of them worthwhile as well as the challenge of finding parts to make the old dinasaurs run, in addition to being alot of fun. Pricey tho, as those of you with the V6s know.

One thing I stress when talking with people notfamiliar with them. THEY ARE NOT A "HOT ROD" MOTOR. They were built to be a working engine, with an enormous torque.
With the now shortage of parts, If you break it, there's a chance it may not run again.

My ramble today for this post.

Re: An old man's journey with GMC 702 V12s
 

Good point about parts. I bought a spare 305 when one came up for sale here just for that purpose. I don't expect to have to use it because I know what I've got. A torque monster. Not a hot-rodder. But if I do need it I have it just in case. I'd like to have another one but I dont have anywhere to put it :lolflag:

Re: An old man's journey with GMC 702 V12s
 

Great thread..
As far as "crossing paths someday"......I'm thinkin that most real GMC guys go to heaven, if they're not already there. Make no mistake, I ain't claimin' to know everything........but I sure have heard a lot of 'em talkin to God when they're fixin' their trucks.
We'll get to cross paths sometime.....no doubt about it.
Thanks again, 'Yote.

BTW.....2000 GPM under who knows how much head psi is an incredible amount of work.
Unbelievable !!

Re: An old man's journey with GMC 702 V12s
 

It was also pushing that water down line, maybe, up to a mile. Have gated pipe on the end out into the water furrows. Better make sure to have enough gates open to discharge, when you cranked up. As the water got further down the line, you could hear the motor loading up, then when the line was full, air pushed out, and water out all the gates, it would then level off.

I don't ever remember seeing a gauge at the pump. We were suppose to gradually increase RPM until the pipes were full, but we have blown some lines apart by increasing throttle too fast.

At night, the exhaust manifolds would be glowing cherry-red. If a cylinder was getting weak, there would be a darker spot on the manifold.

Re: An old man's journey with GMC 702 V12s
 

How cool is that..?
Most folks would be amazed at the physical effects that you experience while standing next to a power plant like the V-12 when you light it up......or maybe the thrill of watching (and feeling) the thing as it takes on a full load and torques over on it's isolators and then settles down and goes to work.
It really does make yer hair stand right up and puts goose bumps all over ya.
I remember some time I spent some years ago while drilling in the Cherokee Strip area ....
I was far away from home, working 7-12's......eating, drinkin' and sleeping ....and then I ran into a bunch of wonderful folks from the Perry area..And that's when the **** hit the fan...
You folks from Oklahoma quickly became my favorite of all time....
I never had more fun while away from home in all my life. Everyone took such good care of me and fed me and made sure I was content...they never left me alone long enough to get homesick. Those folks had me out noodling' on the second weekend....and to an OSU home football game ...I'm sure proud to be an honorary Okie......and still hope to get back there again.......some time before the big round-up.
I'm thinkin you've lived a pretty colorful life.....and I'm sure I speak for the rest of the Forum members when I say that you have an open invitation to rant....or yarn or just plain old BS....Please....Tell us as much as you can about your times in the field and the big ol V-12's. I'm sure there's more grist fer the mill.

Re: An old man's journey with GMC 702 V12s
 

More grist or memories:

We set them to their peak at night.
Since they all used natural gas, as said, at night the pipes would be cherry red. Then we'd watch the fire out the exhaust pipe ends. They were all short stubs about two feet long. No mufflers. Set the time and fuel mixture to highest rpm with about two inches of steady, pointed, bluish, red fire out the end. It was pulling it's best at that point.
Then set the throttle so the pump shaft was turning 1,750rpm, then go home and bed.

We never thought to use ear protection back then, so no need to wonder why we all wear hearing aids, and have ringing in our ears now.

Yep, the memories are good for a 73yr old. Be patient with us ol' timers, as someday, I hope you have as good of memories as we have, back in your good ol' days. Remember those days are now for you.

Re: An old man's journey with GMC 702 V12s
 

Quote "Yep, the memories are good for a 73yr old. Be patient with us ol' timers, as someday, I hope you have as good of memories as we have, back in your good ol' days. Remember those days are now for you."

Well said.

Re: An old man's journey with GMC 702 V12s
 

I got all the patience in the world when an elder is telling adventures like this! I ain't no spring chicken any more either with bad hearing, we never thought about ear plugs working on racecars and in the pits back in the day and that took a major toll too.

Rockdriller is right---"Well said", Coyoterun you can tell more experiences any time far as I'm concerned!

Later---DAC

Re: An old man's journey with GMC 702 V12s
 

I can almost always tell when someone has no idea what they are talking about when it comes to these motors. Usually when they comment on what great racing motors they are. Had a guy out to my place a couple years back who insisted that the v12s were good for racing. Uh..huh... go ahead, push those high rpms... let me get back though so I don't get hit with the fallout!

I'd love to have the energy and shop space (and the v12 of course) to modify one of my trucks. Like maybe the 4000 series I have sitting here with an empty engine compartment. :)