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Thread: The timing mark on the crank pulley....

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    Obi Wan
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    The timing mark on the crank pulley....

    Does anyone have a good picture of the crank pulley that shows TDC and the ideal BTDC mark for best performance?

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    Great Pumpkin TR3driver's Avatar
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    Re: The timing mark on the crank pulley....

    There is only one mark, which should be TDC (unless someone has assembled the pulley wrong).


    The advance curve starts really low on these engines, making it difficult to accurately set initial timing with a light. My suggestion is to start at about 3/16" from the TDC mark (which is about the 4 BTDC called for in the book), and then advance it a degree or two at a time until you can just force the engine to ping a little, by using heavy throttle at low rpm (30 mph in 4th gear) with the engine thoroughly warmed. Then I like to back off by about 2 degrees (half of a hash mark on the distributor vernier), just to be safe.
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
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    Yoda
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    Re: The timing mark on the crank pulley....

    You probably know this Karl that the knurled nut on the distributor will advance and retard the timing

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    Obi Wan
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    Re: The timing mark on the crank pulley....

    Quote Originally Posted by TR3driver View Post
    There is only one mark, which should be TDC (unless someone has assembled the pulley wrong).


    The advance curve starts really low on these engines, making it difficult to accurately set initial timing with a light. My suggestion is to start at about 3/16" from the TDC mark (which is about the 4 BTDC called for in the book), and then advance it a degree or two at a time until you can just force the engine to ping a little, by using heavy throttle at low rpm (30 mph in 4th gear) with the engine thoroughly warmed. Then I like to back off by about 2 degrees (half of a hash mark on the distributor vernier), just to be safe.
    Just speculating: Would a motor with a mild street cam and headers take 8 degrees advance?

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    Yoda CJD's Avatar
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    Re: The timing mark on the crank pulley....

    It's possible. The initial recommended setting is a starting point. The final determination for spark is during driving tests. With the engine fully warm, tranny in 3rd or 4th gear, and about 2000RPM, floor it and see if you get detonation (pinking according to the manual). If you don't, you can use the Vernier on the dizzy to advance a degree or so...then try the test again. Once you do get the detonation, back the timing off a degree or 2 and you have the optimum timing for your engine.

    Oh, in the picture above, Advanced would be with the crank circle to the left of the indicator. Retarded would be to the right.
    John

    1955 TR2

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    Yoda poolboy's Avatar
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    Re: The timing mark on the crank pulley....

    Even if you had a bunch of marks on the damper like a TR6 indicating theoretical degrees that #1 piston is from Top Dead Center, you'll see that the word "nominal" is used in this Haynes manual
    lIGNITION TIMING per HAYNES 003.jpg
    DRIVE 'EM IF YOU GOT 'EM

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