84 GMC C2500, V12 powered

[Rap'em Pappy]

Cayoterun,
It is coming together just great. You have a winner.
Wait til you get that new radiator fitted in and fired it up. How
sweet!!
Pappy

[cayoterun]

Hello, I'm Thumper, and this is now Thumper's truck. Cayoterun thought he'd leave me sittin' over there on the dirty shop shelf when he hauled my '84 GMC cab he cut up to his junkpile. I fooled him, I watched 'til he was ready to crank this one up, then I commandeered it. I'll be around to supervise this mess from now on. We cranked it up today, never run it past an idle for about 1 1/2 hrs. Everything worked pretty good. Wow, what a ride and we didn't even move. He's still has lots of work to do. I'll let him do most of the posting, but I'll be watching. See ya'll around.
Thumper

[1985-GMC]

Good to hear you got it all fired up, before you know it you'll be driving it!

Is that bumper staying on the front?

[Telecasterjoey]

Been watching this thing come together, so cool! One thing I noticed though, That thermostat cover is a little obscene looking lol!

[cayoterun]

Originally Posted by 1985-GMC

Good to hear you got it all fired up, before you know it you'll be driving it!

Is that bumper staying on the front?

The front and rear bumpers are still debatable. I have the stock '46 bumper I can use by redrilling the bracket holes. I have another GMC donor that has the turn signals in the bumper I considered using, but have changed my mind to use the old lights on the fenders.
I'd appreciate you guys thoughts anytime you want to chime in.

I have one salvage yard of any size within a 100 mi. radias from me, so am limited to what I can find in famers junkyards and make work.

Thermostat cover: I've been around these motors for a long time, and never noticed the shape from the side. There's 3 thermostats under there. Thanks for the chuckle.

Cayoterun

[1985-GMC]

I think the '80s bumper looks a little out of place, so id have to say go with the '46 one.

Haha I see it now that you mention the thermostat housing...

[dammitmitchell]

YOU ARE A MEGA DORK! hahaha

hey if you want you can send me that grille and i can try polishing it up for you..
well if you have some good closeups so i can see how bad it is.. but i bet it can be super shiny again.

[dammitmitchell]

also.. have you checked the clearances behind that grille for a radiator? might have to be a expensive one.. but i bet you can fit one hell of an aluminum on behind there with a duel electric fan set up..

that grille combined with the open area below it (from the outside looks) seems like you can get some serious air through it. You could also tilt the bad boy like they in camaros..

[72GMCK-2500]

save the 84 gmc!

[Pyrotechnic]

Three thermostats?! I assume that is because one alone wouldn't have enough flow rate?

[cayoterun]

Originally Posted by Pyrotechnic

Three thermostats?! I assume that is because one alone wouldn't have enough flow rate?

That's right. I forget what the factory specs. give on the gpm it pumps thru those things, but it's unbelievable. When I get a chance, I'll look it up.

Cayoterun

[cayoterun]

Originally Posted by dammitmitchell

also.. have you checked the clearances behind that grille for a radiator? might have to be a expensive one.. but i bet you can fit one hell of an aluminum on behind there with a duel electric fan set up..

that grille combined with the open area below it (from the outside looks) seems like you can get some serious air through it. You could also tilt the bad boy like they in camaros..

Mitch:
I may take you up on the grille polish, but that's a long ways down the road.

Radiator: I was able to stuff a new 5 row radiator from a 5150 Case/IH tractor in it. That dude was pricey, too. I ran it three hrs today at an idle. Used a 14" elect, but wasn't enough, so set a high volumn shop fan in front of the grille too, then it held it's own at an idle, but turn the rpm up, and temp would start climbing. Still some things to try before adding another radiator in the bed. Add a surge tank and some bigger elect. fans might keep it's fever down.

You should have been here and help me break this new overhaul in.

Cayoterun

[McMurray76]

Subscribed! I can't wait to see this thing finished!

[cayoterun]

Originally Posted by Pyrotechnic

Three thermostats?! I assume that is because one alone wouldn't have enough flow rate?

I think I've posted this before but not on this thread. Interesting tid-bits about these motors. This site is where I get my info, plus from a factory service manual I have. At least I can document what sounds like a tall tale.

Oil pump: 17 gallons per minute.
Water pump @ 2400rpm 118 gallons per minute.

http://www.6066gmcguy.org/TwinSix.htm

With this radiator, This set-up holds 12.5 gallons of coolant. I measured it so I'd be sure to have enough anti-freeze in it. I bet I'll have to increase the capacity some way before it's drivable.

Cayoterun

[locomotive breath]

Looking good, I really like the old body style better. Glad to hear that it is running.

[cayoterun]

Originally Posted by locomotive breath

Looking good, I really like the old body style better. Glad to hear that it is running.

Kevin: Glad you chimed in. We may be coming thru there later in the winter.
We'll feed you guys that steak we promised, but haven't made it yet. I hope Texas still has steaks since this drought we're all having.

This body style is alot of fun to work with. It's all bolted together. Also reminds me of the pickups and trucks I grew up with. Makes me feel like a kid again and want to go coyote hunting with greyhounds.

HAPPY THANKSGIVING TO ALL NEXT THURSDAY

Cayoterun

[dammitmitchell]

ya know brother if you were closer id grab a few fand from the junkyard and bring them to you to test fit.
have you made any sort of shroud yet?

i swear i posted a picture the other night of my fan set up for you to experiment with.
try something like this.

[cayoterun]

Mitch: You did post the other day. No, I haven't done anything more concerning cooling, I've been running some at low rpm to get some run time on it, but doing other stuff for a change.
I got the tach hooked up so I can see what the temp does at different rpms. I've run it about 10-12 hrs and 30 gals of propane so far.
I'm sure I'm going to need a remote radiator in the the bed. There's not enough space up front for any bigger radiator without cutting it up more and look like a butchered Peterbuilt.
What is the height and width of the fan you have posted? I can use an 18" fan OVERALL in front.
I have the '72 Ford F-350 radiator, core measurements, 26H x 24W, 4 row, I could use in the bed. Space wouldn't be an issue back there.
I'm trying to get fenders, running boards, and bed rough mounted so I'll know where I might run the lines back there.
I'll pm and we'll talk details and transport.

Bumpers: I'll plan to use the '46 bumpers. My wife seldom offers her ideas, but she came to the shop yesterday and ask if I was using the '84 bumpers. She thought they looked too "modern", like you guys.
Thanks,
Cayoterun

[dammitmitchell]

propane only? you dont run any sort of "normal" gas? hehehe...

is there a chance w the propane the mixture is too lean? (i dont know crap about it so im askin)

[cayoterun]

Originally Posted by dammitmitchell

propane only? you dont run any sort of "normal" gas? hehehe...

is there a chance w the propane the mixture is too lean? (i dont know crap about it so im askin)

I don't think it is. As far as I know, this motor was last run on natural, and generally you have to lean them out on propane. Exhaust smells pretty rich, I'll check tomorrow.
Rap-em-Pappy put gasoline carbs on his and heat is still a problem.

When they were on pumps, we'd go at night. If the manifolds were cherry red, and fire out the stub exhaust pipes about 2 inches, they were just right. If one outlet at head into the manifold was darker than the others, then you had a weak cylinder.
With no load, that don't work.
Cayoterun

[puppy]

Just stumbled upon this thread.

I'll be sitting the 454 into my '46 rat rod very soon. I got the tunnel ram intake installed this weekend.

[cayoterun]

Hello, Puppy:
Neat project your working on. Do you have a build thread? If so, where? I'd like to follow your progress. Maybe we could swap info when we hit a snag we don't know how to fix.
Welcome to the board, Lot's of great, helpful people on here. They've sure help me with a lot of suggestions, and comments.
Thanks, for posting,

Cayoterun

[cayoterun]

Precision hi-tech body alignment equipment or Redneck inginoowity. Whichever,,, it worked.

Cayoterun

[dammitmitchell]

thats awesome...

[Vernski]

Originally Posted by cayoterun

Precision hi-tech body alignment equipment or Redneck inginoowity. Whichever,,, it worked.

Cayoterun

Yeah that's a better way to aline it than the eagle eye. I was wondering what you had in mind for exhaust? I vote for dual stacks that would be cool looking on that old truck. Anyway I'm enjoying your thread you have a good holidays now!...Vernski