Yep kept the boost at about 4psi timing 28 degrees max and swaped out the cam lived for a few summers it was a stock 78 350sbc and was still good running motor until I put a proper motor together if your not too hard on it and keep the boost and timing down it will live for quite some time if you only want the wow factor and not the power gains I had a great time with it most people don't know whats inside the motor anyhow they see the blower thats all
52,000 mile used motor. Cam, big tube headers, under-driven pulleys, rich carbs, and good cooling system. I ran it 3yrs, and the guy who bought it still has it, and that was over 30yrs ago. It's not his daily driver, but it still sees some street and track every year. Biggest headache I had was with oil film from the front case, and that damn belt dust. Could sure screw up a clean engine compartment.
This 671 is on a basic stock motor. Drives the **** out of it. I'm betting he has 20k on that set-up. It's the one on the left.
I ran one for a while due to budget restraints. Mid 70's 350, 76cc heads, and I'm guessing cast crank and pistons. Guessing cause I never opened it up. Put an SFI spec damper on it, 1/2 fuel line, big fuel pump and 3" pipes. Ran the blower 11% underdriven and mild on the timing and generous with the fuel. Most I ever sawn the boost guage was 6lbs. Mostly driven sedately, but occasionally not, and it never popped in a bit over a year of driving.
Anyone run one on their daily?? i need a little more umph outa my warm 283 and i think the compression is what needs to be changed. What is the life of a 671 anyway?? Most cars ive been around havent seen enough miles to need a rebuild on them
I ran a 8-71 on a 327 in my ot Camaro a few years back. The engine was stock, including cast crank and pistons. It did have a decent cam and a good MSD ignition and a good damper. It was my daily driver in Phoenix for over a year and I drove it over 60 miles a day round trip. It was underdriven but would see 6 lbs of boost. I could get around 12 mpg if I babied it. Brian
my blown 383, dart pro 1's, 6-71, 2- 500 edelbrocks averages 13 mpg if you drive it normal in my street car,when it was in my dragster it ran 132 mph in the 1/8 and drank 3 gallons of alky
yes i have ran stock gm detroit 6-71's on stock sbc's as well. no major problems, you just have to remember your limits when driving and building
Yes I have been running GMC blowers on stock small blocks for the last 30 years.several 6-71's and a 4-71. I have never had a catastrophic failure caused by the blower. Use a little common sense,and they will run for a long time. The whine of the blower belt never fails to turn heads,driving down main street on the way to work.
I was wondering what size of Pulleys are recomended ?. I want to machine my own v-belt crager style for a simalar set up For my model a .almost stock 350. even if some was willing to measure there regular blower belt pulleys. I could work it out. Sorry if im thread jacking
Just figure it out at 15% underdriven make pulley sizes accordingly don't go too small as you need enough surface area so they do not slip how many belts? I would say min size 5 " with three belts. I run mine 10% under AFR 210 heads comp blower cam dual 650 holley vac secondary makes 8-9 psi boost and gets 17 mpg on highway with 4l80e with 411 gears 26.5" tire just don't p*** anyone because it will drop the fuel econ to gal/mile but ya gotta love it
Is there is anyone on this thread can tell me the height of a 6-71 blower case? from carb flange to where it bolts to the heads? thanks
My gmc 671 case is 7 5/8 from intake manifold surface to carb plate surface. The carb plates I have vary but around an inch give or take a 1/4. Add the plate to 7.65 Can't tell you about about a scb intake but my hemi manifold is an old why-and low profile and the bottom of blower case is just about even with the valve cover mounting surface of the head.
Thanks 31 Vicky, that should get me close enough to do some thinking.. someday would like to try one on my A
Von, I have 7.500" from the top of the case{ not including the carb base plate } to the bottom of the case where it bolts to the intake. For the SBC add 3.6875/ 3 11/16" to the dimension to go to the bottom of the intake, TR
allright, im going to measure now, its killing me 15" from the intake flange to the bottom of my hood, 8" for carb and aircleaner and 7.5" for blower, .5" for carb plate..dam thats tight, probably too tight for my luck
Good deal, I usually fiqure 11 3/16" from the bottom of a intake port to the top of the blower, 6-71 in this case. TR
I just saw this thread, But it reminds me of the early days of Fremont Dragstrip. Some Guys, I can't remember the name, Brothers I think, Ran a dragster, Blown fuel, with Desoto engine. They would take an engine out of a junker, add the 671, and I think they changed the cam, and run it. it always ran well, but every once in a while it would blow up. Then they would stick another junk engine in it.
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