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6-71 Blower Install

Discussion in 'The Hokey Ass Message Board' started by wheels777, Jan 20, 2009.

  1. wheels777
    Joined: Oct 29, 2008
    Posts: 163

    wheels777
    Member
    from York, PA

    This subject has been discussed before. But, there never seams to be a step by step process included. I have a 6V-71 core that was given to me. It is in decent condition. Building a manifold is not an issue. How do I set-it up to run on a SBC? The goal is to do and spend as little as necessary to install on a low buck rod. Can something as simple as multiple timing belts be used to drive the blower? Do the end covers get sealed (with a breather) and filled part way with oil?
     
  2. krooser
    Joined: Jul 25, 2004
    Posts: 4,591

    krooser
    Member

    Build your manifold first. Various length drive snouts will get you close on you belts then you can shim the pulleys to get everyting lined up.

    You need high speed bearings and new seals.. the stock blower runs on engine oil via an oil line. The front cover runs in 80W90 gear oil... the rear bearings are packed with grease.

    You also need a rear beraing plate and modify the front cover by making a "triangle" plate so you can fill the cover with lube. Aftermarket covers will usually have a pressure relief valve installed.. it's not a toy to impress your friends with... the cover's seals need some pressure to keep sealing properly.

    Visit the sites of BDS, Dyers Blower Service and others for more info.
     
  3. JC Sparks
    Joined: Dec 8, 2008
    Posts: 537

    JC Sparks
    Member
    from Ohio

    Here is a question I've been ask a hundred times at the track, How much oil goes in the front cover? 20 ounces. JC
     
  4. Homespun91
    Joined: Jul 2, 2006
    Posts: 2,791

    Homespun91
    Member

    I would recommend that you invest about $20-25 and buy the book Street Supercharging by Pat Ganahl... http://www.motorbooks.com/Store/ProductDetails_7667.ncm
     
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  5. Shifty Shifterton
    Joined: Oct 1, 2006
    Posts: 4,972

    Shifty Shifterton
    Member

    Buy a used $75 manifold that's got stripped threads or a crack and fix it. The whole notion of making a readily available SBC manifold is absurd.

    Now you've got all that fab time saved up for making your drive system. :)

    One unavoidable obstacle is the physics of drive belts transferring power and the amount of torque it's gonna take to turn a 6/71. You'll probably find that when 3 or 4 timing belts are summed up it makes $$ sense to use a real blower belt and looks less hillbilly.

    When you start talking about using a real blower belt, suddenly looking for a used piecemeal pulley set, or buying 2 pulleys and making one, become viable options.

    Sometimes the cheapest way to go fast is spend money. Yes you read that right.
    When talking used SBC speed parts, it's real hard to make something for less than you can buy it.

    good luck
     
    Last edited: Jan 20, 2009
  6. He said it was a 6v71. Nobody makes manifolds for that blower so he's on his own.
     
  7. Isn't that the most popular size?
     
  8. revkev6
    Joined: Jun 13, 2006
    Posts: 2,858

    revkev6
    Member
    from ma

    6/71 gmc blower:
    [​IMG]



    6V-71


    [​IMG]
     
  9. Shifty Shifterton
    Joined: Oct 1, 2006
    Posts: 4,972

    Shifty Shifterton
    Member

    Oops, I went by the title. Yeah a V manifold is an issue on a budget.

    FWIW you can put aftermarket drive non-V snouts onto a V with minor trimming and use readily available 4/6/8-71 drive stuff.

    good luck
     
  10. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 3,113

    Ebbsspeed
    ALLIANCE MEMBER

    There is a difference between a 6-71 and a 6v-71. The 6-71's were used on the inline engines, and were mounted on the side of the motor. The 6v-71's are from the V-type engines, and mounted between the cylinder banks, and have a completely different mounting scheme.
     
  11. brandon
    Joined: Jul 19, 2002
    Posts: 6,039

    brandon
    Member

    a customer of mine had a dyers v6-71 setup.....used a 1/2" or so thick plate that was bolted to a regular manifold....looked fairly easy to replicate....must have worked , as his little s10 with a stock cam and decent heads and short block went 10.70's with the deal.......:D
     
  12. dbradley
    Joined: Jan 6, 2007
    Posts: 1,037

    dbradley
    Member

    The "6v" has a weird case (for lack of a better word). Its NOT what you would see normally. Dyer's makes a manifold for one but probably not too many used ones laying around. Others make 'replacement' cases (use the other parts internally) that will fit the 'normal' 6-71 manifolds.
     
  13. Tony
    Joined: Dec 3, 2002
    Posts: 6,760

    Tony
    ALLIANCE MEMBER

    I had a Dyer's prepped V6-71 blower on my old 32 coupe too. The intake that was used to build the blower manifold was an Offy low rise dual quad intake.
    They machined off the whole carb area and welded a flange to the existing intake that accepted the blowers bolt pattern.
    Considering the area the dual quad's take up on the intake, i still think that idea would be the best way to approach this. Only because the area below what's needed to be removed is already close to the length of the blower flange.
    Just my thought's only because of what i had myself.

    As far as belts, i agree with Shifty on this. I'd look around for non V style components and make them work. Of if you feel real crafty, make your own V-belt drive assembly for it..

    Deffinately spend some time visiting, and talking to the people at the blower sites. They know what they are talking about and will be able to lead you in the right direction.

    Tony.
     
    Last edited: Jan 20, 2009
  14. Oh snap, I missed the "V". I remember being down in the engine room of my dad's boat, had 6-71 diesels in it; and seeing the blowers, and thinking how cool it would be to put one on the family car...
     
  15. Kenneth S
    Joined: Dec 15, 2007
    Posts: 1,491

    Kenneth S
    Member

    You could use multiple v-belts (like 2 or 3) to drive it (it's the cheapest way to drive it), the only downside (the main reason v-belt drives aren't used) is that the belts start slipping when the blower starts making 6 psi or more of boost, if 6 psi is enough for you v-belts will be ok (it would be nostalgic looking).
     
  16. KeithDyer
    Joined: Mar 26, 2007
    Posts: 193

    KeithDyer
    Member

    6-71 mounts with straight up studs and bolt holes, 6V-71 has an angle set-up with splayed bolts / lugs to hold it down.

    I think the rotors and gears might be the same but the case is the problem.

    K
     
  17. Kenneth S
    Joined: Dec 15, 2007
    Posts: 1,491

    Kenneth S
    Member

    Sell the 6v-71, and get a 6-71 it's easier to deal with, plus part are more readily available for the 6-71.
     
  18. continentaljohn
    Joined: Jul 24, 2002
    Posts: 3,270

    continentaljohn
    Member

    Kerry, Dyers make a intake for the V671. It's a low profile inake and a very neat setup. I'll look for a picture of it. I know a Hamber that has problems with Blowing rearends :D using one of them V671's.
    I have a Duel Quad intake for a SBC that I'm going to sell off for 120 bucks. What you would have to do is install a Pop Off valve onto the intake or blower plate to install the V671. Oh yea have a v671 forsale too:D
     
  19. Kenneth S
    Joined: Dec 15, 2007
    Posts: 1,491

    Kenneth S
    Member

    Dyer USED to make a sbc 6v-71 intake in the 70's.
     
  20. Tony
    Joined: Dec 3, 2002
    Posts: 6,760

    Tony
    ALLIANCE MEMBER


    EXACTLY. I called them last year and talked with a tech because i had the rebuilt V series on my bench... He said they CAN still make one, but it would be a little over 800$ to do it..NOT worth the money.
    The one i had on my coupe was one of thier's.

    Short of fabricating your own items to make the V6-71 work, it will be COSTLY...

    I sold mine and bought a nice, used 6-71 instead, and i know i'm further ahead.

    Tony
     
  21. Interesting... I've heard of making a blower plate but never of a manifild made for the v series blower. If you have a picture of the dyers manifold I'd love to see it.

    As far as the vbelt drives go, mine is good for about 7.5# of boost so far w/o slipping. That's about all the engine likes so I don't think I'll be making another pulley for more boost.
     

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  22. Tony
    Joined: Dec 3, 2002
    Posts: 6,760

    Tony
    ALLIANCE MEMBER

    Here's a couple pics i took for when i listed it for sale. It's a bit hard to see because i painted the intake itself black and left the flange that they welded on polished...
    But, you can see the thermostat housing is in the stock sbc location, and the blow off plate behind it. It even had the oil fill tube provision in it, just blocked off with a soft plug.
    I wish i had better pics of the set up itself, but i can't find any right now..

    Like i said, this wasn't a Dyers cast intake, it was without a doubt an Offy dual quad intake that they modified for the install of the V blower.
    I actually had/have another car with the style Offy intake they used but unmodified.
    The other pic is of the intake i'm talking about on the sb i put in my 57..Thats what my blower intake started life as. you could visually see where it was machined to fit the flange, and welded..Very nicely too.


    PS..I had the helmet air cleaners like what you posted on it when i drove it...But didn't want to let them go so i sold it with the stacks :)
     

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    Last edited: Jan 20, 2009
  23. continentaljohn
    Joined: Jul 24, 2002
    Posts: 3,270

    continentaljohn
    Member

    The one I had from Dyers was a "Billet:eek:" manifold and that most likely the 800 clams. What I liked about it was the low profile and shaved off 3" or so.


     
  24. Tony
    Joined: Dec 3, 2002
    Posts: 6,760

    Tony
    ALLIANCE MEMBER


    Could be. I didn't ask once he said 800..
     
  25. wheels777
    Joined: Oct 29, 2008
    Posts: 163

    wheels777
    Member
    from York, PA

    I definitely plan to make the intake. I have the perfect piece to modify.

    What is the issue with the bearings and seals? How much boost can the original end plates take? Is there an econo drive? Will the V6-71 make 10 pounds or is it limited? Someone posted 7.5 earlier in the thread...what do you do?
     
  26. You can make a lot more than that but you probably don't want to. The question is how is your engine setup and what does it like. Do some searches here on the HAMB. There has been a lot of blower engine discussion.
     
  27. Tony
    Joined: Dec 3, 2002
    Posts: 6,760

    Tony
    ALLIANCE MEMBER

    Yep.. and if you plan on doing it low buck like you said, you may not want to run too much boost anyway...the lower end should be prepped for what it's going to do or you will be paying for it again..
    The pic i posted of my 32 was a fairly mild 283..Not a big buck deal but it did try and make sure i wouldn't drive over the crank.....it put about 5-6lbs of boost.. And hauled ass.
    In a lightweight rod you don't have to do much when running a blower. Mildly boosted it will probably produce enough power to make you think about the next time you hit the go pedal..
     
  28. zbuickman
    Joined: Dec 9, 2007
    Posts: 447

    zbuickman
    Member

    Why 10 PSI???? is this motor set up for this???? I personally would not start out with any thing higher than 5# (Being very careful) and dial it up from there.:)


    Boost is boost and I run 20#, 22*timing, 8:1 compression and 110 Octane. In one toy and am working on a 10# 8:1 pump gas 454 right now. (after I figure out how to put a Ford stick tranny behind it)
     
  29. continentaljohn
    Joined: Jul 24, 2002
    Posts: 3,270

    continentaljohn
    Member

    I picked up a intake that was modified and not sure why? It's a old crager with the pop off valve on the bottom . I guess it can be used for a 671 or 471 now? What kind of intake are you going to modify?? How would you do the pop off valve?

     

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  30. Shifty Shifterton
    Joined: Oct 1, 2006
    Posts: 4,972

    Shifty Shifterton
    Member

    FWIW you can run 4-6 psi on just about anything and get away with it.

    10psi is purpose built blower setup territory.

    Boost amount is more than the blower, it's a function of the engine underneath it. Engine takes more air, less boost is developed. For example using a non-blower cam with long overlap will allow intake pressure to bleed off and cause lower boost, all other things equal.

    What's important on the blower side of things is actual rotor RPM. They have a redline too, and put a bunch of heat in the air when approaching redline. That heat causes all kinds of badness in the combustion chamber.

    So if you're serious about this home fabricated drive, you need to establish the blower drive ratio based on your engine's redline, and how hard you wanna drive the blower.

    One of the beauties of over the counter style pullies is if you hit the street and realize it's too much boost for fuel & conditions, you're a phone call away from less boost. Same deal if you get power greedy and want a 14psi weekend with a tank full of race fuel.

    Maybe you could incorporate one off-the-shelf pulley, or find a way to switch the blower/crank pulley for 2 boost rates without extra fab'd parts.

    good luck
     

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