84 GMC C2500, V12 powered

[cayoterun]

After 5 days of hard work by Pappy fishing, splicing, and running wires, Thumpers truck made her first "out-of-barn" debut. Drove it for awhile in the pasture. Still need lots of work. The hose over the cab is the propane fuel line from small tank in bed. Cosmetics can go any direction now. We debated much on whether she needs a cheap coat of Almond rustoleum paint/w black fenders and running boards, or leave as is.
With the 700R4 tranny and 4:10 gears, top speed of 70mph+- @ 2400rpm. Have some 3:42 gears available to increase speed to 90+- @ 2400 if wanted.
With adding insurance and a little more tinkering it's will be street legal.

Thanks, Pappy, and Mrs. Pappy, have a safe trip back to Wisconsin. Hope your "new V-12" proves to be a good one.

Cayoterun

[1985-GMC]

Man that thing looks cool, I'm really digging how the bed hangs off the back so far!

[Palf70Step]

That looks so great!

[dammitmitchell]

still showin off brother! and almond with black is awesome!

[cayoterun]

Originally Posted by dammitmitchell

still showin off brother! and almond with black is awesome!

Yep, Mitch- if it wasn't for the inter-net, all I'd have is prairie dogs to try to impress. (grin)
In a few days after I get some more lights and little stuff done, I'll try to get Haystack (my son), to put a short video on his utube.

Jokin' aside, I'm liking the way this old flivver is coming together. The shorter wheel-base makes it handle alot better. It seems like a much better set-up than the long wheel-base on the '62 GMC 1 ton. For sure, I like working with the old simple construction of sheetmetal on the '46. The '84 GMC 3500 frame and suspension is carrying the weight well, and rides much better even out in the rough pasture.

Hope the move and new job are treating you and yours well.

Cayoterun

[dammitmitchell]

it is man! im havin a blast, getting ready to register my "88 landscaping truck" and take down my camaro for the winter, build another motor, declip it and do a bunch of little time consuming stuff like ... ummm.. rust repair.. (i hate those words) and i might FINALLY get all those suspension parts i bought last winter installed.

you sir have made much more progress this year then i have !

[locomotive breath]

Looking good. I'm glad to hear that its running, but now we need to see that video.

[INSIDIOUS '86]

Seen these guys? http://thunderv12.com/
Posted via Mobile Device

[cayoterun]

Originally Posted by INSIDIOUS '86

Seen these guys? http://thunderv12.com/
Posted via Mobile Device

I've followed this link for some time. He has some great accurate info, especially about the "pitfalls of building/having a V-12". I'd like to hear his rebuilt and hopped-up ones turned up to 4-5,000 rpm. I'm sure it's would be quite a racket. They are loud enough at 2400.

There's 3 or 4 of us on this site that have one or more of them. Our goal is aimed at preservation, but like to package them in such a way we can let others see/hear them run. We'll never abuse the motors in any way, as we know if we break it, it may never run again, due to shortage of parts. They will make plenty of noise, throw rocks, and smoke the tires enough @ 2400 or less.

We're amazed at the number of people who never knew the V-12 existed and we enjoy showing them. They are sure a part of GMC's history, but they are a workhorse, not a hotrod motor.

Cayoterun

[dammitmitchell]

have you seen this?
http://67-72chevytrucks.com/vboard/s...d.php?t=547647

[cayoterun]

Originally Posted by dammitmitchell

have you seen this?
http://67-72chevytrucks.com/vboard/s...d.php?t=547647

No, I hadn't seen it. I'm sure all here knows that's Rap-em-Pappy's truck, a member here.

I'll pass it along to him, tho.

Thanks for letting us know.

Cayoterun

[Rap'em Pappy]

I am back with the cheese heads. We had a great time with Cayoterun and
family. It is always fun scratching our heads and twisting bolts with good
friends. That truck is sweeter than the pictures show. We got it running like
a top. That first run is priceless, as it is with all of us old gearheads. Cayoterun I bet you still have that big old grin. Now the plates can go on and head that v12 down the highway.

[Rap'em Pappy]

I see the post about other v12's http://67-72chevytrucks.com/vboard/s...d.php?t=547647 I had both my v12's at a show this summer. The
semi v12 is interesting to drive. Without a trailer on back, it is like driving
down a railroad track. It gives a whole new meaning to "put your seat belt
on" Mrs. Pappy drove the long nose, she likes it better than her Buick...The sound of the pipes, The pipes on the long nose sound mean & green with the cutouts open. It has a distinct tone of its own.....just ask the Indiana county police. He followed me 12 miles, just to question me what it was......

[locomotive breath]

Nice looking cabover Pappy. I don't guess I have seen that one yet. I see you used Super Singles on the rear too. Where did you get the back wheels? I had some custom made at "Wheels Now" for my Mack but they were kinda pricey but I guess that is a relative term.

[Rap'em Pappy]

I have a good friend who works at a truck tire company. The rim wheels I think
where Bud type rims. I changed from 20 in to 22.5 first. He searched the
state for 6 months. These rims were from a cement truck in norther WI. The
445/60-22.5's are free to me as all the tires. They are take offs when the
road trucks get a new set. He is a dodge man, so as horse trading goes, I
have some old dodge trucks in my shop to restore.

[crazy longhorn]

Originally Posted by 1985-GMC

Its a Detroit 12v71 852ci 2 stroke Diesel.



Now you wouldn't want to go do something like that...

At times , I think about sweepin that shop, turning the lights out & go fishin...the problem is , that I just drown perfectly good worms stick with what you really love crazyL

[cayoterun]

CrazyL, I'll probably keep on keepin' on. Been at it for over 60yrs, and still enjoy it as much as when I started.

It's a harmless, but wallet wrecking hobby, but Momma don't have to wonder where I am.
Besides, other wrench heads are a great bunch of people to spin yarns and tell lies with.

Heck, that ain't nothin'. Back in '61, I slapped a split manifold, and dual carbs on '54 Chev 235 and that thing would--------. and the end of your yarn would out do your buddies last one.
Old Geezers have good imaginations,

Cayoterun

[cayoterun]

Originally Posted by locomotive breath

Looking good. I'm glad to hear that its running, but now we need to see that video.

Yep, LocoB. It's good to drive it. Pappy brought a prod stick, and alot of work, so that's kinda' re-inspired me. I haven't put the 3:42s in yet. If/when I do, I'll have a buddy at a local shop change them. The 700R4 is sure nice. The adapter you designed and built is working great, thanks.
Since the weather is cooler, and running it outside the shop, the engine cooling has improved alot with existing tractor radiator.

Have you done any more to the cab-over? We'd like to see it mobil. It would add another interesting application for the motors.

Pappy took another runner home this trip. If I find another, I'll pick it up for a spare, in case one of ours shucks. They are getting fewer, since scrap iron prices are so high.

Maybe Haystack will get a video posted before long.
Tell your better half hello for us,
Cayoterun

[cayoterun]

Is it ok for a grown man, (72 yo at that), to cry or do we like new challenges?

The motor picked up a low rpm knock. Below 1,000 rpm, it sounds baad, increase the rpm and it goes away. Finally dropped the pan and one head. No cuttings, or chips of any kind anywhere. Has without a doubt been rebuilt, standard bearings in rods and mains. Pistons .30, and cylinder walls clean, smooth top to bottom. on the ones I've checked. While I have it open, I'll keep going and check all 12 cylinders. If I don't find anything, then will slide the tranny back and recheck the fly-wheels. It's possible I failed to torque all the bolts good, or a used auto flex-plate I used could have had worn bolt holes. I sure want to find the trouble if in the motor, because I don't want to ruin all the hard to find new parts in there.
I was lucky when I mounted the motor. I have room to drop the pan without having to pull motor mounts loose. V-12 tidbit: The pan has 40 5/16 bolts holding it on.

Cayoterun

[dammitmitchell]

that absolutely blows!
good luck brother!

[Palf70Step]

and that's a LOT of bolts to take out.

[1985-GMC]

Best of luck my friend, I hope it's something minor!

[cayoterun]

Not really related to this truck, but an interesting story on a V'12 pump motor:
I was talking to a friend who I grew up with last night about this. He and his brother farm big a few miles from here. No way to tell how many of the 12s they wore out. He said they had put a new one on a well years ago. It had a vibration in it, that wasn't bad, but not right. They ran it serveral days that way. Dealer checked it, couldn't find anything, finally the dealer came, took it back to shop, and tore it down. Started pulling bearing caps. Pulled a main bearing cap, and the factory had left 1/2 of the main bearing out. Put both halves of new bearing in, and the motor ran for years.

So, factory will goof now and then.
Cayoterun

[cayoterun]

A WHOOPEE moment. Found my engine knock.

When I pulled #5 piston, finally found it. Never saw a piston break like this. Has anyone else? The piece was still in place and never made a scratch on the cylinder wall. It broke between 2nd and 3rd rings and about 1-1/2" long. The piston and piece were worn where they rubbed together when flopping around. Now the search for the elusive .30 over piston and rings.

Cayoterun

[Palf70Step]

Glad you found the knock. Good luck with your search.