An old man's journey with GMC 702 V12s

[Cayoterun]

and other stuff:

I had fixed up cars, pickups, and travel trailers, since I was a kid. After retirement, but still on the farm with a shop, I wanted to get outside the box.
GMC V12s had been used by the hundreds here on farm irrigation wells, during their hey-day. Bullet proof, and indestructable. I found the one I cared for in 1965 in a neigbors barn. Decided I'd like to hear it run again. After 20+-yrs pumping water, it had broken piston and head. Found the parts in junk yards. When I got it running, I decided to put it in a truck, so the project evolved, instead of being planned. The first post was Aug. 07.
This was named by forum members "Balaur", which means " mythical Romanian 7 headed Dragon".
The build thread and video links:

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Donated it to Cimarron Heritage Center, (museum) Boise City, Ok. There she sits in her permanent home.

Later, I found another running V12, so started another truck. As you can see from beginning to now, her build also, took more crooks than a snake from beginning to now as a '46 Chev, pu.
She's ugly, but I like her and is alot of fun. Called her "Thumpers Truck" I found the rabbit in one of the parts trucks I used, so decided it would make a good mascot.
I made my first post 7-10, and on page 11, videos are post 258. Hop in and we'll take a noisy ride. Max. recommended RPM is 2400, so this motor won't never be turned more than that intentionally.

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Thumper will report her future adventures as they go along, and this 72 yr old will be grinning from ear to ear.

I want to add my thanks here to my V12 buddies, Rap-em-Pappy, Locomotive Breath, and all the others that have helped me along with the 12s. Last, but not least, Jolly Goodfellow and all his people on the old site for their help.
Someday, I hope our paths will cross face to face.



May all our future trails we travel here on this new forum be full of good times, and not much blood lost from skinned knuckles.

[6066gmcguy]

Next time you want to Donate a V12 truck, cross my my path with it eh.

Last time I got a truck donated to me in a will, it was sold to pay the outstanding deit of the donor.

[Cayoterun]

I'm trying to learn a little more primative 'putor stuff today, so don't know what kind of mess this post might be. If so, I can plead ignorance with complete honesty.

My wife of '46 yrs. made her first suggestion on any of my projects today. Ever!! We were talking about taking "Thumpers Truck" out to it's first public debut at a meet this summer. She volunteered that she thought I should leave the paint as-is. She thinks it looks more appropriate, and authentic for it's age and locality, instead of painting it all almond/w black fenders and running boards, like I intended originally. I painted the firewall almond when I had the cab off and stripped. If Mama approves,--- I like it,too!!!

I hope this link will bring the post with the videos over here.

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Jolly: I doubt this truck will be donated. It's starting to grow on me as everthing has come together much better than I expected. With the stock '84 GMC 3/4T running gear, it drives good, front suspension carrys the weight well, and is much more agile with the shorter wheel-base, and with the 700-R4 tranny, you can get up to road speed without the risk of over-revving it. Eventually, I may add the 3.42 gears which will slow the motor more. I don't intend to ever be smoking tires or giving it a very hard throttle, as I wonder if the tranny would take the torque. Not worth the risk.

It looks like this one post transferred, so it might be better for me to transfer selected posts instead of the entire build thread from time to time with my limited savvy on this critter.

If I ever decide to sell it, it will go on E-bay. Several friends here has offered to buy it, so, to be fair to all, without ruffled feelings, I feel it best to put it up for public bids, IF that time ever comes.

[Cayoterun]

"Balaur"

Pics. taken at Santa Fe Trail days celebration, 6-4-10, Boise City, Okla., parade, and Cimarron Heritage Center, (museum).

The '47 Spartan trailer house was local trailer, had been used for storage at Boise City for several years, but had been used there for years as a residence. A son still lives there. He let the museum have it, and I restored it in my shop for them. It is totally functional as it was in 1947. Spartan was built in Tulsa, after they quit building aircraft for WWII. It's now Spartan School of Areonotics and Engineering. We pull it behind "Balaur" in the parades sometimes.
One neat thing about the trailer resto. was when we took it back out there. We had the son who lives there to meet us on the edge of town at a Dairy Kreem, so he'd be the first in town to see it. He lived with his parents as a boy in it, and he and everyone in town thought it was junk. He was really pleased it had been restored and would be in his hometown's museum.

The fellow in passenger side of "Balaur" is 85 yrs old. He bought the new '62 GMC pickup. Wore it out, parked in pasture for years, but sold to me to modify for the V12 engine. I gave the truck title to the museum that day, so he was pleased his old pickup would be in the museum, too. We left dents in the cab intentionally, and he can give the history of each one from farm use.

[Cayoterun]

Balaur's V12 as I found it in 2nd owners, Ted and Darla Summers, old shed.
I worked for the original owner, Meb Mallard, in 1965 when the motor was new on an irrigation well pumping 2,000 gpm. Summers bought it, then ran it 'til about '81. He retired it until I got it and put it in "Balaur". Appro. mileage based on hrs. on pump is equal to about 5 1/2 million miles. Number of rebuilds unknown.
This is how the motor looked when we pulled it out of it's extended hibernation on 7-11-07. Was good to hear her blow fire and thunder after all those years.

[Cayoterun]

Our family old car era from '86-'98 as we restored old first cars for all the kids, then my splurg on the '58 Impala to take back to my 40th class reunion.
We graduated in '58. Three of the kids still have their's in storage, but drive on special occasions. Each kid helped build their cars, both girls and boys.

68 Firebird
65 Chev Impala
64 Olds Cutlass
63 Ford Galaxie

[Cayoterun]

As I've driven this pickup about 400mi. locally, the bed somehow didn't look right. Then I remembered as a kid, they generally had grain side boards on them during wheat and maize harvest. Probably only old geezers will remember them looking like this during the 40s and 50s. They would haul 60-70 bushels. 65 bushels @ 60# per bushel meant they would pile around 2 tons on them. Off the wife and kids would go for the grain elevator, while Dad harvested another combine bin of grain, back in the good ol' days.

The old 6-cylinder engines would chug right along about 25-30mph with that big of a load. No ps, pb, ac, or auto tranny.

[FetchMeAPepsi]

That looks classic Coyote! I really dig that ol' custom job of yours.:notworthymulti:

[Cayoterun]

I extended the fuel range some with the 80gal fuel reserve tank. The little 16gal tank of fuel didn't last long. Can go about 40mi. before refill. Lot's of idleing included in that number, tho.

I haven't been able to find a tank to fit where the little tank is mounted in front, so had the 80gal tank on hand that would sit behind the wheel wells. Plan to get the truck away from home on weekends some this summer, so needed more capacity in case no propane was available on weekends. The big tank is temperary until a smaller 30-40gal tank that will fit is found.

[6066gmcguy]

Thats A Nice Bomb you have there in the bed.

Good to see some one getting out on the weekends and showing off one of those V12s.

[Cayoterun]

Thats A Nice Bomb you have there in the bed.

Good to see some one getting out on the weekends and showing off one of those 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.

[Cayoterun]

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.

[FetchMeAPepsi]

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:

[Rockdriller]

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 !!

[Cayoterun]

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.

LOL, I agree!
I guessing by your avatar, you've worked in the oil patch or somewhere around hi-pressure lines?

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

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.

[Rockdriller]

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.
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.

[Cayoterun]

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.

[Rockdriller]

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.

[GMCDAC]

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

[David R Leifheit]

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.

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. :)

[Cayoterun]

Hello, David:
First time I've seen a post of yours over here. Welcome to the new site.

I've read your posts over on the other site, and you gave alot of helpful input over there.
You have much to offer here, keep it up.

Yes, the things you read on the inter-net or otherwise is kinda' amusing at times, others with misled understanding by first look at one, and lack of research before commenting. Not only on the 12s, but on the V6s also.
I laughed when I read your comment about turning them up to 5,000. I'd be just like you, and head for a hiding place. There would be a heck of lot of pig-iron flying around if it blew. I've unintentionally run one up to 3500 or so on a pump, and dreaded to get close enough to hit the kill-switch. It would vibrate the concrete slab, the stand was sitting on. Was also afraid, it would throw the pump shaft off. No scatter-shields, (guard) on the shaft back then, either.

Join us in the chatter when you want, it will always be helpful.