a little reading says it was based on the 305 v6 so maybe have to do some more reading b4 i can say for sure.... actually for the price its worth getting, id love to do a heavy hauler hot rod..
Thought this was a rodding board, not a scrap it if you can't run it off a boat tank strapped to the roof board.
WTF? Like the fact that I rigged my old pickup to run around the block with a fuel tank on the roof has any bearing on how easily it is to obtain parts for a 637 (which is nill, I've looked into those monster V8s myself for the fun of it). You got a secret stash of 637 V8 rebuild kits laying around? If it needs a rebuild it's as good as scrap because there are no parts for them. What do you suggest, custom machining rebuild parts? We aren't talking about a friggin' Pierce Arrow straight eight engine here. A slow revving v8 that weighs more than a small car does not sound like hot rod material at all. Besides while you let your cars rust into the ground trying to get some ridiculous price for them I actually drive mine and have fun
I use that example (that per the post said the truck was driven all around for an entire season that way) to point out that if you're that lazy and unwilling to even put a real fuel pump on a vehicle, you're probably also the kind of guy who'd just scrap something rather than spend the time to track down parts you can't just buy over the counter at Napa. Some people get it, some people don't. We have over 200 cars, there isn't enough time in the day to spend to fix every one of them, but without us they would not otherwise exist, and every penny from a sale goes into buying more cars that otherwise would be scrapped. Again, some people get it, and some people just don't - and probably never will.
Total mind reader, not I've saved a few cars and trucks from the crusher too, but at least I ask a reasonable price so someone will buy it and hopefully fix it up instead of sitting on them thinking I have a little rust colored pot of gold. But then I guess it's better to let something rust into the ground because you think it's worth a pile of cash and have it deteriorate even further. Besides we aren't talking about a car anyway, it's an engine out of a bus that needs a rebuild. Great, so where does one get rebuild parts for a 637 V8? Do you have any real advice or just a bunch of BS rants about saving something that you'd let sit out in the field until your long gone thinking it's worth 5 grand
dang folks! i wasn't looking to start a fight.. and the owner says it ran well 3 years ago... but who knows...
Well I'd just see if it runs, if it runs good I'd say good enough and slam it in whatever. Although you won't see very good mileage, those old big gas V8s love fuel (2-3 mpg empty). I've ran across a few GMC big block V-6s. Very durable motors, the V-12 was advertised as a 200,000 mile motor back in the early 60s. Impressive for the era. GM did convert them to diesel. I believe they called them Toro Flow diesels which weren't known to be all that great. You might be able to get very basic parts (like a fuel pump or a water pump) but I wouldn't hold my breath if I were you trying to get much more than a gasket set. I know when I tried to find parts for an early 80s gas International 404 V8 all I got was a bunch of eye rolling from the large truck parts guys. Even finding parts for my 88 UD that I used for hauling milk was a pain (more eye rolling but I was able to get the parts).
2-3 mpg!? crap! maybe ill just sell it and put the proceeds twards a cat motor or something.... but i have always wanted a huge motor for something.... i think that motor would be at home in a COE. to haul what ever
There's a reason why there aren't any large gas engines anymore Later gas engines got better mileage. I averaged 8 mpg out of a 404 in an International S1800 empty. Truck moved pretty good for something that had a 20 foot box on it that weighed about 15000 pounds plus. I'd imagine in a lighter chassis it would tow just about anything you'd want to tow but then finding parts for it was a pain. Those old gas jobs aren't worth much more than scrap price. Big trucks are cheap, too hard to work on and they cost too much money to pass inspections. If that 637 V8 runs good you might get 500-600 bucks maybe but I'd think it would be more likely that it'll sit for a long time especially at current fuel prices. I'd advertise it on old big truck forums, someone there might want it for parts or a replacement since the motors are getting pretty rare. Those guys have a bit of money. People complain about how much it cost to fix up an old car, just imagine what it would be to fix up an old 40s White or Mack and then fixing up a trailer from the same era too
Have a look at this site. If anyone can point to a source of parts for these old engines, then this is the place to start looking. http://www.6066gmcguy.org/ Keep us posted on your progress and just ignore the nattering nabobs of negativity.
LOL, Im not too sure what you were expecting with a 10.4L old technology V8. Originally I was going to ask if you owned an oil & gas company, or at least had considerable stocks invested in one, but decided not to out of kindness. Id say 3mpg sounds about right with something of that size.
Do you have any pics of the engine? I wouldn't get to excited about the 2-3 mpg deal. Remember, that was in a big, heavy, truck or bus, not a light hotrod, with highway gears. With a little research, you can probably find modern bearings that will work, but they may need small mods. Everyone makes custom pistons, so no worries there. Tell someone like Dema Elgin, or Joe Paneck how you want the engine to perform, and get them to re-grind the cam. Joe will even make you a new cam blank. I used to hear the same things about the GMC 302 straight 6, low revving, etc. Funny thing, they turn them over 7000 rpms, and 220+ mph, now. It would be a very cool, powerful, unique hotrod engine, if you took a little time to do it right. ...hmmm, 637 CID, blower,6X2's.....
These guys are here in town. If it is the same as the v6 and v12 then I'm sure they can get parts for it. http://www.thunderv12.com/
The 637 was a 60 degree V8 and shared the same bore and stroke as the GMC 478 V6. Bore and stroke of 5.125" - 3.86". The 637 replaced the 702 Twin Six V12 in 1966.
Looking through my truck repair manuals that engine was rated 275 HP at 2800 rpm.A 60 degree V-8 is not right so it appears a gear driven balance shaft was used.Bet it weights 900 pounds or more.I bet if it reved over 4000 rpm the engine would be a light lighter after the crankshaft fell out. Maybe Carrillo can build some rods for it
Even the little 305 in a Pk would only get 4 MPG. Those engines have really heavy large internal engine componet,s and too much internal bearing amd piston drag to get good fuel economy. Now they will pull anything you can hook them to.
1970 Motors truck repair manual says 600 ft lbs at 1600 rpm. Lot's of torque that's for sure.You would need 1.8 rear end gears to get speed out of it.
Automatic overdrive, 3.08 gears,28" tires, 75 mph= 1940 rpms. 5 speed about 2200 rpm's. 2.72 gears drops the numbers to about 1700, and 1950 rpms. Plenty of torque to make it work.
Stumbled on this ages ago when a local fellow dropped a twin 6 v-12 in his 32 coupe www.6066gmcguy.org. Lots of info
all rebuild parts for a gmc 637 v8 can be found at memphis warehouse in memphis,tnn. right now there only 3,of the 637 v8 in the nation ,they are very big engine's weight about 1200 pounds,375 hp at 1600 rpm's 800 pounds of torque at 1600rpm's,all the parts are the same as whats in a gmc 478 v6 rings, bearings,valve's....
i was going to get a v12 an put it in a t-bucket,but someone has already beat me to that,,if you wish to see it or them there's more than one,,go to google type in 702 V12 T-BUCKET an you will see,,has no trouble burning the tire's up,,so ,,i'm going to put a 637 v8 in one,,that will be fun!!
The Jalopy Journal
