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TR2/3/3A Ignition timing questions while I'm waiting for Spring

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There is nothing to argue about when it comes to the picture of my damper.
On my damper..the wide hash mark is TDC, the somewhat thinner hash mark to the left of the wide TDC hash mark represents 4*After Top Dead Center....BTDC to the right side of TDC, ATDC to the left of TDC on engines who's crankshaft rotates CLOCKWISE when viewed from the front looking aft.
 
Karl, do you still have the original pulleys? If so that picture is not like what you will be looking at. Check this out:

YvTjwuA.jpg


In this pic you can see the small hole in the pulley, and the pointer on the chain cover. It is shown at top dead center TDC, although the angle of the picture makes it look about 2 degrees after TDC.

So, if you want 4 degrees, you would turn the crank in picture to the left, so the pointer is to the right of the pulley hole. Of course, it is recommended to always turn the crank in the direction of running rotation, as that takes up any play in the chain or distributor in the correct direction.
 
I like and always fall back on the TR3 timing instructions on Macy's Garage. My TR3 doesn't have a TDC hole in the pulley. I usually remove the valve cover so I can get as close as possible to TDC. The drive and advance until it pings idea is an art I have not mastered. I'm just patient and get it to run as good as I can.
Good Luck!
 
If you use the piston stop method, you can locate the true TDC and mark the damper accordingly, be that with a dab of paint or a hash mark, a shallow file cut on the rim of the damper.
Measure circumference of the damper and by division you can again hash mark any of the 360 degrees from the true TDC that you want for an ignition timing reference.. if that's your preferred method.
 
CJD said:
Karl, do you still have the original pulleys? If so that picture is not like what you will be looking at. Check this out:

YvTjwuA.jpg


In this pic you can see the small hole in the pulley, and the pointer on the chain cover. It is shown at top dead center TDC, although the angle of the picture makes it look about 2 degrees after TDC.

So, if you want 4 degrees, you would turn the crank in picture to the left, so the pointer is to the right of the pulley hole. Of course, it is recommended to always turn the crank in the direction of running rotation, as that takes up any play in the chain or distributor in the correct direction.
Click to expand...
So the 4 degrees BTDC timing mark would be to the "right side" of the small hole TDC mark, correct.
 
Advanced timing would be before (ahead of, leading, sooner than) top dead center in the direction of rotation. But you can't obsess about the precision that is simply not available, nor intended to be available, by the factory supplied timing mark. Get it running by best guestimate, move the distributor head to what sounds like maximum RPM at idle and then retard the timing to scrub off 100 or so RPM. The valve ping test is helpful, but if you can't hear it, it doesn't matter and don't try to improve things beyond the RPM drop described. If you want to be uselessly precise, static time with the pointer at the hole (TDC) and then adjust the little click wheel on the distributor to advance the desired amount. The clymer manual will tell you how much advance you get from each click of the wheel. I can't remember what that is. I say uselessly precise because the effect of the advance/retard wheel on the system varies from used distributor to used distributor
Bob
 
So the 4 degrees BTDC timing mark would be to the "right side" of the small hole TDC mark, correct."

That is correct, by about 3/8" as you said before.
 
poolboy said:
There is nothing to argue about when it comes to the picture of my damper.
On my damper..the wide hash mark is TDC, the somewhat thinner hash mark to the left of the wide TDC hash mark represents 4*After Top Dead Center....BTDC to the right side of TDC, ATDC to the left of TDC on engines who's crankshaft rotates CLOCKWISE when viewed from the front looking aft.
Click to expand...
OK. I finally got it đź‘Ť đź‘Ť
 
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