8-71 blower

[olddog]

I have an 8-71 blower off of a 318 detroit diesel. It is a twisted lobe design. I believe people adapted these to car engines back in the day. One end has what appears to be a govorner in it. It may need a different bearing end cap to get rid of that. The engine was running fine, when the blower was pulled this spring. It was an old truck that was scrapped out for the metal. I think the truck was mid to late 1970's.

I think an 8-71 blower new at Jeggs is around $2500. That's a polished new blower ready to go, which this one obviously is not. I not looking to get rich. If no one is interested, it may become a tractor driven leaf blower.

[trularin]

You won't get enough out of it to blow leaves, But what do you want to get out of it???

[olddog]

I really don't have a hard price in mind. I was thinking around $300, but will consider offers.

I haven't pulled any blower charts, but expect it to be able to pump at least 1000 CFM and easily push 10 PSI. I think with the right nozzle it would move some leaves.

[Jerry Clayton]

Can you post a picture of it? If it is right off a truck and has the stock case it isn't worth much--I put the first 8.71 blower for a dragster together with a special lengthened 6.71 type case and end plates built by Leonard Van Luven at Donovan engineering in the early 70's. We could run a lessor overdrive ratio for more efficient power output. The biggest drawback was the way stock cases were formed, with the angled side bolts just didn't wook out very well, but the rotor diameter was the same as 6.71 rotors but 3/4 in longer so we added some to both ends of the case molds and used the end plates for the 6.71 on them, spaced crank pulley and front drive out 3/8 inch, the rear cleared the mag o/k and injector fit the top-
If I remember correctly we qualified #1 and won the race

Jerry

[Jerry Clayton]

For pictures see my photo gallery--altho the blower on the car in the picture is a 6.71, we put the 8.71 on shortly afterward

Jerry

[WV66AC]

Momma is a divorce attorney -- said she would file on me when I suggested a blower for le batard a while back. I am left to whine because I can't have the whine of an 8-71. Sigh.

[olddog]

Jerry,

I'll take a couple pictures tomorrow. However I have no idea how to post them on here or anywhere else for that matter. I need some instructions.

[Jerry Clayton]

The 8.71 blowers had bolts going down thru the end plates and 2 on each side at an angle. The 6.71 had four bolts down each side and none thru the end plates

Jerry

[olddog]

Ok I have loaded the pictures into my photo gallery.

I went ahead and pulled the govenor housing off and the intake housing, so you can see the rotors. There is some oil and grime on the rotors. I do not know if that is unusual or not. I did see the engine run. The rotors turn free.

There is a tag on the govenor housing. It has idle speed on it. It is a GMC. I assume the blower is also GMC. That is what I have heard it should be, as well.

Jerry,

This blower has the two bolts on each end going down through the bearing housing, as you said, but it has three bolts going down each side at the angle.

[olddog]

With the site down for a while and the London show, I just wanted to bring this up to let people see the pictures in my photo gallery. I can make someone a better deal if they are interested. However aflter riding in a Cobra with a 513 (460 stroked) crate engine, I cannot see how anyone would need a blower on a big block.

[Aussie Mike]

That's an 8V71 and it's a bit different to the 8-71 at Jeggs. These are designed to mount into the V of the engine and have a different kind of flange than the regular 6-71 and 8-71 blowers. You can see the luggs on the side of the blower case where the hold down bolts lock into. Very hard to fit one up to any of the readily available automotive blower manifolds as they all cater for the flange style mounting of the 6-71.

Cheers

[Jerry Clayton]

The 8.71 is not a practical choice for mounting with the GMC stock housing and endplates--the ones you see in Jegs/Summit and other places have a housing copied from my work with Donovan/Van Luven in early 70's to lengthen the 6.71 housing for the 3/4 longer rotors--the end plates and bearings from the 6 71 type worked so we only had to make a housing--this sorta finally happened because of the Nixon days when gas went above $.30 and shortages were everywhere--there were no stock GMC housings available ( Van Luven said they were the best) and Donovan was going to make his own--I persuaded him to make his patterns a little longer so they could be used for both blowers as I knew that Van had hid a new 8.71 at Isky when he worked there--I convinced Isky to sell it to me( just the rotors) and Van Luven built the blower like a 6.71 , we had to space the crank hub and idler mount 3/8 in forward to center the blower and still clear the magneto on the rear.

Your blower looks pretty tired and used up -- for the $$$ needed to fix it you probably should just recycle the aluminum

After the chance to tell a story about the old days, I'm sorry to have to say that--


Jerry

PS--I agree that with a big block, a person certainly doesn't need a gmc type blower on a Cobra

JErry

[olddog]

After I did a little cleaning to take those pictures, I realized there was some wear showing on the rotors. Without taking it apart, I don't know the condition of the housing, bearings, or timing gears. It may be rebuildable and it may not. I would want to rebuild it to perfect condition before I put it on an engine, but for a big leaf blower, who cares?

If someone wants it fine. Not a big deal to me one way or the other. Thanks for the conversation though.