Tech query-timing

Discussion in 'General Amphicar Discussion' started by Paul Dwyer, Aug 22, 2000.

  1. Paul Dwyer

    Paul Dwyer Guest


    I want to set the dwell and timing, but the tech manual is not as much
    help as I would like.

    First, I have to determine whether the engine has 6.8:1 or 8:1
    compression. I have queried the owner about this, as the book doesn't
    indicate a data plate code that would tell the tale.

    I'd like to use a strobe and dwell meter to make the adjustments, but
    the book only says how to do it with the engine off. (Though it says
    more adjustment might be necessary "during the road test," haha.) Thus
    there's no spec for the dwell, just the point gap.

    The flywheel has a notch that I assume indicates TDC on the No. 1
    cylinder. (The relevant section, page 1/56 in my book, makes no
    reference to the relevant illustration on the opposite page. Hmmm.) But
    I don't see a scale indicating degrees BTDC. So even using the "turn the
    engine until the points open" method, how can you tell precisely the
    degrees from TDC? With a protractor?

    If I can't figure this out, I'll set the timing "by ear" using a
    tachometer and vacuum gauge.

    I'm guessing that overly advanced timing is to blame for the dieseling
    and overheating (the latter could be from other causes, I know) we've
    been experiencing, but we'll see. Given the universality of detergent
    gasoline, does anybody de-carbonize their piston heads and combustion
    chambers anymore?

    Speaking of overheating, I got to thinking about electric water pumps.
    Fuel-injected, hi-po and customized engines tend to use electric fuel
    pumps, and most cars nowadays have electric cooling fans, but I've never
    heard of electic water pumps. Seems to me to be the perfect solution for
    overheating--turn off the engine but keep the water flowing. Since the
    car's not moving, you won't get shock cooling. Anybody heard of adapting
    an electric pump to an Amphi engine?

    Paul Dwyer
    1968 Rambler American
    1967 Amphi (Phyl's)
    1945 Vought F4U-4 Corsair (1/72 scale)
    1999 Mac G3
    2000 No. 2 pencil

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