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Hot Rods Best overall firing order for two big-block engines in tandem?

Discussion in 'The Hokey Ass Message Board' started by oldandnew, Aug 6, 2014.

  1. oldandnew
    Joined: Nov 15, 2012
    Posts: 16

    oldandnew
    Member
    from FL

    What is the best way to couple two big block engines in tandem?
    Like the 'priapism' rod
    http://www.rodauthority.com/news/video-the-twin-engine-priapism-is-the-hot-rod-end-game/

    How should their firing orders be straddled?
    What about something like
    1st engine 1 8 4 3 6 5 7 2
    2nd engine 7 2 1 8 4 3 6 5
    as to keep the successive firings on every engine side evenly spaced out.

    Or maybe keeping firings apart for smoothness, like
    1st engine 1 8 4 3 6 5 7 2
    2nd engine 7 2 1 8 4 3 6 5

    Besides smoothness or performance which of these (or some other) firing order would sound better?
     
  2. Blind Elwood
    Joined: Jul 1, 2010
    Posts: 229

    Blind Elwood
    Member

    I would hate to see the camshaft bill on what your thinking. The best way in my opinion is to have the second engine fire 10* after the first. I never built a engine for sound, seems like a lot of extra effort with no horsepower gain. Chain them together and be done with it.
    Elwood
     
  3. rooman
    Joined: Sep 20, 2006
    Posts: 3,967

    rooman
    Member

    Elwood,
    if you look at the numbers he is not looking at changing the actual firing order of the engines, just where #1 on the second motor would fire relative to the first engine (at least I think that is what he means).

    Roo
     
  4. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,065

    Rusty O'Toole
    Member

    There was some discussion on this before, in threads about how to couple 2 engines together. A search should turn up some in depth information.
     
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  5. I got to thinking about this subject one time and asked an engineer friend about it. His opinion was that if you fired both engines at the same time you double the power spike in the second crank, cutting its life in half. If you fire one engine between the firings of the other engine, you don't change the power spike, but you double the number of spikes which cuts the second cranks like in half. His opinion was it doesn't matter which you do, as long as the power spike isn't great enough to cause immediate destruction, the crank in the second engine will last half as long. How long is half as long in the question!
    My personal opinion is to set it up so each engine will fire between the other, fit 180 degree headers and have a sound that will peel the paint off your competitions car.
     
  6. Gerry Moe
    Joined: Jan 29, 2006
    Posts: 498

    Gerry Moe
    Member

    Its a question like this that makes the ordinary joe feel like he knows nothing. I don't see any difference between the first example of the two engines to the second example of the two engines. To me they would sound the same if they both had the same tune. Maybe the Toymaker will chime in here.
     
  7. Go on a Tractor puller site.....
     

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