Timing Marks Problem

[Taylormade]

Dumb question of the week.  This plate is bolted over the hole in the bellhousing that allows you to see the TDC mark on the flywheel.  I my infinite wisdom I forgot to document this when I took it off three years ago.

 

 

So, which arrow goes on top, the TDC (DC) or the timing mark (IGN 10 degrees)?  The position of the stamped letters indicate DC should be on top, but the position of the metal arrows seem to make more sense with the ING on top.  Any experts out there that can help this confused old guy?

[Spinneyhill]

Is ignition 10 deg. before TDC? Then fit accordingly based on direction of turning of the crankshaft.

[Gunsmoke]

I believe you have it correct in your other thread, i.e. the "ign" pointer is at top. If it was flipped 180 degrees, the wide part of pointer would block view of flywheel marking. Technically, the crank/flywheel in your photo is rotating clockwise, and as seen, the TDC mark/groove on the flywheel is a few degrees BTDC when iginition occurs, normal for these engines.  My '31 Chevrolet 194 CI 6 cyl was factory set for ignition at 12 degrees BTDC. With the better modern fuels, tech experts recommended gapping my cars spark plugs at 40thou versus 28thou, and setting timing 16-18 degrees BTDC for smoother running.  Seems to work better. Dodge flatheads may be a different beast. You may find a good mechanic who can tweak timing when car is running by adjusting at distributor, assuming your distributor has an adjusting collar that permits distributor to be rotated slightly. If I recall (I am not a mechanic) the engine makes 2 full turns (720 degrees) for one rotation of distributor, so 10 degrees of flywheel rotation is only 5 degrees of distributor rotation. TMI? Cheers

[Taylormade]

Thanks, Gunsmoke, some good information.  You,too, Spinny.