GMC 702ci V12

[BigAL]

So if you bought one what would you do with it? For me I just picked one up and want to do a tank car with it.

Here's a pic of what they look like.


This is Jay Leno's tank car.


And here's one that some other guy did.

[Deaf Bob]

I'd put it in something with a long hood.
Here in OR, I want fenders and a top as well as a hood!
I wanna see guy's jaws drop when I open the hood!
Mid 70's Coupe de Ville or the ilk...

[Barry Donovan]

I'd put it in something with a long hood.
Here in OR, I want fenders and a top as well as a hood!
I wanna see guy's jaws drop when I open the hood!
Mid 70's Coupe de Ville or the ilk...

my first thought was the caddy... a 2 door.

A real challenge would be the FWD eldorado, or seville with the funky chopped off trunk.
goofy long hood needs a goofy v12 with a bellhousing cutout of the floors.

delta88 was another big weird one.. my dad had both.

[68scott385]

Remove the driven fan corresponding fan shroud from my '75 Monte Carlo and it should fit just fine.

[Dan Barlow]

67 chevy / gmc pick up. I'd move what ever I had to , to get it under the hood without moving the firewall .Radiator under the bed or something.

[oletrux4evr]

What's it weigh?

[Deaf Bob]

If I remember correctly, the GMC V-6 weigh a bit more than a small block chevy.. So. The weight of 2 SBC+?

[Deaf Bob]

Huh? Looking for weights, found this..

702
The 702-cubic-inch (11.5 L) V12 "Twin Six" was offered in United States GMC commercial trucks, and as a special order option in Canada. It was mistaken as two V6 engines welded together, but it is its own separate engine design based on a single casting.[1] It used four separate exhaust manifolds, two separate carburetors, two separate distributor caps driven by a single distributor drive,[1] and other parts from the 351. 56 major parts are interchangeable between the Twin-Six and the other GMC V-6 engines to provide greater parts availability and standardization. It produced 250 net SAE horsepower (190 kW). Torque was 585 lb·ft (793 N·m).

[Deaf Bob]

Basically tow 351's...


351
The 351-cubic-inch (5.8 L) 351 had a 4.562 in (115.9 mm) bore and 3.578 in stroke (90.9 mm). It was basically an enlarged 305. In 1972, the 351 was replaced by a 379.
I know the 305 was heavier than hell, and so underpowered it burned lots of fuel
A hotrodded 702 with lighter pistons, bigger valves, some porting, good cam porfile should easily produce nbrs claimed above..
Probably expensive as all get out too..
Since it is a 2.5-10 ton truck motor... Probably likely heavier than needs to be for the stump pulling power needed...
Maybe be ok in a dualie crew cab with a couple turbos?

[Deaf Bob]

702= 1485 lbs dry.

http://www.6066gmcguy.com/EngineData.html

3 times the weight of a small block chevy for lots of torque and maximum rpm of 2400. 250 hp..

[squirrel]

...but it's a friggin VEE TWELVE!!!!!!!!!!!!!!

[Deaf Bob]

What's it weigh?

1485# dry...
See post 10's link for more info..
Max rpm is 2400..
275 hp
630 tq

[OldMachinist]

I have a cousin who used them as natural gas fueled engines on his irrigation wells for a while. Went to diesel based engines converted to natural gas when he had to drill his wells deeper. They weren't really much of an engine then and haven't improved with age. It is something different for a clown car though.

[BigAL]

• GMC Built the 702 from 1960 to 1965 as a gas V12.
• The engine is a one piece V12 with four heads that were also used on the GMC 351 V6.
• The block is one piece not two v6's joined together.
• Two different block castings were made. Some parts do not interchange between the two.
• The cam and crank are 4 feet long.
• The crank is a 180# forged steel.
• The engines were produced for tractor-trailer semi-truck motors.
• The 702 was never affiliated with the GM diesel line of engines. The 702 was always a gas engine.
• The Factory V12 was rated at 630 Lb-Ft torque and 275 HP and was governed at 2,400 rpm's.
• ThunderV12 moved the torque curve from idle to the 2,000 to 3,000 rpm band. The HP figure jumped to 425hp at 4,200 rpm.
  http://www.thunderv12.com/faqs

[oletrux4evr]

...but it's a friggin VEE TWELVE!!!!!!!!!!!!!!

I think I'd rather have a 3000 hp Merlin......