Popular Post NY-B61 Posted November 19, 2014 Popular Post Share Posted November 19, 2014 A gentleman near me owns this beauty and several others. All of them run, though not frequently. He's a wealth of information on the history of trucking in our area as well as the history of trucks in general. He's a genuine pleasure to spend a sunny summer afternoon with while he tends to his collection. 6 Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/ Share on other sites More sharing options...
2stacksuperdog Posted November 19, 2014 Share Posted November 19, 2014 12V71? interesting looking Quote Matt Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267297 Share on other sites More sharing options...
Enck762 Posted November 19, 2014 Share Posted November 19, 2014 Gas job i'd guess. Guy in my town had two chevy's just like this with lime spreaders 6v53 detroits used them into the 2000's. Pretty sure he bought new. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267302 Share on other sites More sharing options...
j hancock Posted November 19, 2014 Share Posted November 19, 2014 GM had a setup where two gas V-6 engines were tied together. Don't know all the details but there was a cab over shown at Macungie with this motor and it looked pretty impressive. 2 Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267303 Share on other sites More sharing options...
NY-B61 Posted November 19, 2014 Author Share Posted November 19, 2014 GM had a setup where two gas V-6 engines were tied together. Don't know all the details but there was a cab over shown at Macungie with this motor and it looked pretty impressive.I believe I remember him telling me the exact same thing. He said it would scream when wide open! Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267304 Share on other sites More sharing options...
j hancock Posted November 19, 2014 Share Posted November 19, 2014 I bet while it was screaming, you could also watch the gas gauge going down very quickly!2 to 3 mpg probably. Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267308 Share on other sites More sharing options...
NY-B61 Posted November 19, 2014 Author Share Posted November 19, 2014 Gallons per mile. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267309 Share on other sites More sharing options...
carlotpilot Posted November 19, 2014 Share Posted November 19, 2014 texaco oil had a bunch of those critters v12 gas they would out pull a 380 cummins on a hill at something like 1/2 mpg doing it Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267324 Share on other sites More sharing options...
Superdog Posted November 19, 2014 Share Posted November 19, 2014 They were 702 cu.in.,basically two 351 V6's 1 Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267325 Share on other sites More sharing options...
Brocky Posted November 19, 2014 Share Posted November 19, 2014 Ivan Taunton of Snead AL has one in his shop right now in the process of restoration. Quote Brocky Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267333 Share on other sites More sharing options...
mowerman Posted November 20, 2014 Share Posted November 20, 2014 nice thanks for sharing...bob Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267406 Share on other sites More sharing options...
Bigdogtrucker Posted November 20, 2014 Share Posted November 20, 2014 I had a twin to that but with a 671,wish I kept it!V12 would be a neat hobby truck! Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267407 Share on other sites More sharing options...
Popular Post 41chevy Posted November 20, 2014 Popular Post Share Posted November 20, 2014 Gas job i'd guess. Guy in my town had two chevy's just like this with lime spreaders 6v53 detroits used them into the 2000's. Pretty sure he bought new.702 c.i. Twin Six V 12. I sold one a while back to a hot rodder for his project. 6 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267412 Share on other sites More sharing options...
NY-B61 Posted November 20, 2014 Author Share Posted November 20, 2014 That's a monster! Could it be set up for dual carbs? The one in the photo looks like it's set up for a single. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267418 Share on other sites More sharing options...
vision386 Posted November 20, 2014 Share Posted November 20, 2014 Everytime I see one of the GMCs I am reminded of a favorite childhood toy!.............................................Mark 1 Quote Mack Truck literate. Computer illiterate. Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267420 Share on other sites More sharing options...
41chevy Posted November 20, 2014 Share Posted November 20, 2014 That's a monster! Could it be set up for dual carbs? The one in the photo looks like it's set up for a single.Originally they came with a pair of Rochester 2 barrels. That engine had an intake adapter to run on LNG. The piece in the back is the drive and advance adapter for the pair of 6 Cylinder distributors. Made in stock form about 250 275 h.p. @ 2400 rpm and 585 or 630 pounds of torque @ 1600 rpm. weighs in at a tad over 1500 pounds. Thunder V-12 makes a high performance Twin Six Magnum 956 cubes 500 plus h.p 735 pounds of torque @ 5000 rpm to the tune of $10,000 starting with your engine. 1 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267425 Share on other sites More sharing options...
theakerstwo Posted November 20, 2014 Share Posted November 20, 2014 Here Texaco oil had I think 5 GMC with that engine. I worked nights then at freigfhtliner and I had most of them saved for me to tune up and I think they needed that done ever two months.The firing order and plug wiring was done like two inline six cyl side by side and they had two dist caps running off of one dist.They also had some autocars with 250 cummins and the drivers claimed they would run with the 250 cummins in the hills but would run faster on flat land.I think I remember them turning 3100 rpm but do know they had a tamper proff governor. It wa vacummin and if you disconnected itit would only idle and the weights for the governor was in the oil pan on the oil pump.They had a single one piece block and crank but four heads.In 1966 the mack dealer here built 5 or maybe more F model cab over mack from scratch with that engine as power.Ten speed roadranger trans with SQHL on Henderson springs. 1 Quote glenn akers Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267434 Share on other sites More sharing options...
NY-B61 Posted November 20, 2014 Author Share Posted November 20, 2014 Deleted but can't figure out how to fully delete. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267436 Share on other sites More sharing options...
NY-B61 Posted November 20, 2014 Author Share Posted November 20, 2014 Originally they came with a pair of Rochester 2 barrels. That engine had an intake adapter to run on LNG. The piece in the back is the drive and advance adapter for the pair of 6 Cylinder distributors. Made in stock form about 250 275 h.p. @ 2400 rpm and 585 or 630 pounds of torque @ 1600 rpm. weighs in at a tad over 1500 pounds. Thunder V-12 makes a high performance Twin Six Magnum 956 cubes 500 plus h.p 735 pounds of torque @ 5000 rpm to the tune of $10,000 starting with your engine.Thank you for the great info. I had an American LaFrance with a Lycoming V-12 that had twin carbs and distributors also. Were dual distributors factory on your 702 V-12? Did it have a dual or single spark plug arrangement? Great picture also! Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267437 Share on other sites More sharing options...
russoniellov Posted November 21, 2014 Share Posted November 21, 2014 Would be great to see it restored, very cool truck, must be rare to see one. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267499 Share on other sites More sharing options...
NY-B61 Posted November 21, 2014 Author Share Posted November 21, 2014 Would be great to see it restored, very cool truck, must be rare to see one.It gets a lot of attention because of it's location and visibility but I've never seen another one like it in person. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267501 Share on other sites More sharing options...
Popular Post 41chevy Posted November 21, 2014 Popular Post Share Posted November 21, 2014 Thank you for the great info. I had an American LaFrance with a Lycoming V-12 that had twin carbs and distributors also. Were dual distributors factory on your 702 V-12? Did it have a dual or single spark plug arrangement? Great picture also!The dual distributors were OEM off a common drive with the Advance in the drive. Pics are easier to explain it. main partsTwin Six ready to go in 1947 GMC COE Hot Rod 8 Quote "OPERTUNITY IS MISSED BY MOST PEOPLE BECAUSE IT IS DRESSED IN OVERALLS AND LOOKS LIKE WORK" Thomas Edison “Life’s journey is not to arrive at the grave safely, in a well preserved body, but rather to skid in sideways, totally worn out, shouting ‘Holy shit, what a ride!’” P.T.CHESHIRE Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267532 Share on other sites More sharing options...
j hancock Posted November 21, 2014 Share Posted November 21, 2014 Wild Stuff. Thanks! Quote JimIt doesn't cost anything to pay attention. Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267536 Share on other sites More sharing options...
Joe Ditchkus Posted November 21, 2014 Share Posted November 21, 2014 There was a late 30's early 40's Chevy or GMC Rat Rod Pickup at the ATHS Show in Springfield,Missouri this last May. It is owned by Steve Hartz from Colorado. It had a V-12 702 GMC gaspot with a 10 speed Roadranger. If anyone gets Wheels of Time it is in the pictures from the Show Truck Edition. Joe D. Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267546 Share on other sites More sharing options...
NY-B61 Posted November 21, 2014 Author Share Posted November 21, 2014 What a brute of an engine. Thanks for the explanation, diagram and GREAT pictures! Quote Link to comment https://www.bigmacktrucks.com/topic/37783-gmc-7000/#findComment-267547 Share on other sites More sharing options...
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