Advancing the cam and distributor ??s

Discussion in 'General Auto Conversion Discussion' started by oldcrow, Feb 11, 2020.

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  1. Feb 11, 2020 #1

    oldcrow

    oldcrow

    oldcrow

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    I am building a 1/2 VW engine, and want all my power to come in at or around 3600 rpm or less. I know that on my distributor i can change the weights (mechanical) so that it comes full advance early or late depending on where you want your power band. also i have an adjustable cam gear to do the same with my cam timing.
    so for those who know about engine performance do i advance my cam an go lighter weights on the distributor so that my power band is in the lower rpm range or do i have it all backwards.
    thanks, Ken
     
  2. Feb 11, 2020 #2

    Mcmark

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  3. Feb 11, 2020 #3

    oldcrow

    oldcrow

    oldcrow

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    thank you for the read Mcmark. i found a low duration cam with a higher than stock lift, so with advancing the cam pull my hp down and will make the engine more "torquey" all the way to my max rpm range. Lighter springs in the dist. will have my advance come full in at 2400rpm. when i mock up my engine i just have to make sure i have exhaust valve clearance for the cam advancement.
     
  4. Feb 11, 2020 #4

    pictsidhe

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    You'll need to experiment. Move the cam around and see what gives the best rpm on the prop. Ignition timing will have an optimum too. You may need to retard a little if you get more power from the cam phasing. Don't bother changing dizzy weights, it takes a lot of effort to map and tweak an advance curve. When messing with timings, be careful to avoid detonation from too much advance.
     
  5. Feb 11, 2020 #5

    Pops

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    After all of your testing you will find that for swing a straight drive prop, the stock VW cam and cam timing is hard to beat.
     
  6. Feb 11, 2020 #6

    oldcrow

    oldcrow

    oldcrow

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    thanks for the input guys, i think i'll just stick to a stock distributor, mech. advance, but with electronic ignition (the mds dist. was in 300$$ range too much for little difference)
    as for the "bigfoot cam" it is just a little over stock duration but a noticeable lift.
    for those interested ---> link---> https://www.cbperformance.com/product-p/2209.htm
     
  7. Feb 12, 2020 #7

    pfarber

    pfarber

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    Do what the early Flatheads did... Adjust the timing manually, but add a vacuum gauge to monitor power.
     

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