Offenhauser Q-Jet 2x4 Manifold

Discussion in ''Da Nailhead' started by Bigpig455, Feb 16, 2019.

  1. Bigpig455

    Bigpig455 Fastest of the slow....

    This has nothing to do with the motor build, but I though some of you would find it interesting;

    Those who know me know I'm a die-hard Q-jet fan, and when this manifold came up on e-bay I bid not necessarily to win, but to at least come close at my number...I'd never seen a dual spread-bore manifold in person, and neither had anyone else I talked to.

    Anyway, I won the auction by .60 cents, and the manifold show up undamaged. I looked it over and couldnt believe what I'd bought. Russ Martin claims the square bore Offy's will kill power by 60 hp over a stock manifold, and this one must have been twice as bad. When they grafted the spread bore carb pads to the square bore blank, they didnt bother to open up or connect the ports, it was totally unusable. The bolt holes didnt line up at all with the throttle plate locations. Looked great, completely useless.

    So Centerville offers a Offy "fix" on their website and I sent it out to see what he could do. After a little re-negotiation on the price (I knew before I sent it he wouldn't even break even at his posted rate) he got to work.

    I'm sorry I dont have any good before pics but the work Russ is doing is quite interesting, and he feels this manifold will actually perform well when he's done. Given the port configuration he initially though he'd just have to open it up to a single plane "360" configuration, but with the addition of some aluminum pipe for port routing, he's been able to maintain the dual plane config.

    This manifold was always going to be for "exhibition" purposes only, was never counting on it for full on ET's so it'll be interesting. Ken from Everyday Performance has built a couple of side inlet Buick Q-Jets for his own 430 project that he'll let me borrow, so we may actually see what this thing can do this summer - fingers crossed.

    Attached Files:

  2. GranSportSedan

    GranSportSedan Puppet dictator, wife has all power

    I too am a firm believer in the Q-jet. Looking forward to seeing how this turns out.
  3. techg8

    techg8 The BS GS

    That thing is waaay cool
  4. gs66

    gs66 Well-Known Member

    Very cool piece!
  5. nailheadnut

    nailheadnut Riviera addict

    If you love Q-jets, this should light your fire.

    dan zepnick and techg8 like this.
  6. Bigpig455

    Bigpig455 Fastest of the slow....

    The Quad Quad Olds!
    techg8 likes this.
  7. GranSportSedan

    GranSportSedan Puppet dictator, wife has all power

    OMG, that has to be a carb tuning nightmare.
    techg8 likes this.
  8. John Codman

    John Codman Platinum Level Contributor

    Just because you can, doesn't mean you should. Aggravation is proportional to the square of the number of parts in the assembly. If one Quadrajet has an aggravation factor of one, that setup has a factor of 16. No thanks! Having said all that, the thing sounds pretty good.
    322bnh likes this.

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