Ignition: Basic Timing pointer question for '63 289

[PlainBrownR2]

The '55 has a basic timing pointer on its 289. There are three marks on the dampener; UDC(Upper Dead Center), IGN(Ignition), and IN-OP(Intake Open). Before you drop a distributor in the engine and rotate the engine around to TDC, which timing mark is that pointer supposed to line up with at TDC, to align the distributor with piston #1(UDC, IGN, IN-OP)? I thought UDC, but I think it's IGN .....

[PlainBrownR2]

Found the answer, UDC indexes Top Dead Center on the #1 piston on the compression and exhaust stroke, IGN indexes when the piston fires, and IN-OP indexes when the #1 intake valve opens. UDC is needed when setting valve lash(the crank will be at UDC twice for the compression and exhaust stroke), so it gets spun twice. IGN is needed to be in alignment with the pointer when the distributor gets dropped in.

In my case I needed to know this because I am redoing some stuff on the trigger wheel, and the VR sensor needs to be aligned with the 5th tooth away from the missing tooth since it's a V8, and that the sensor needs to reference TDC and the crankshaft centerline. The engine needs to be at TDC for this ignition system to work, and I believe I may have gotten the timing off by aligning it on the exhaust rather than compression stroke. The end result was vehicle backfiring into the intake and exhaust manifold, and refusing to start, so that needs to be addressed. The vehicle also isn't running at the moment due to some modifications that went awry last month, and discovering the VR sensor bracket got loose and threw everything out of alignment down there. So we're putting everything back to the way they were before this happened

[Cus63]

On this subject, my light isn't a dial type, how far to the right of the IGN mark would be 45 degrees advance?

regards, Cus

[bensherb]

I indexed the damper. Each mark is about 5 degrees,(there are many more marks that don't show in the pic) if I remember right they're about .305" apart, so 45 degrees is about 2.442" from the I mark on the circumference. (just get it in the ballpark and if it pings back off a bit)

[Cus63]

Thanks Ben,
In the mean time I have scaled up this template, could you please check against your marks,

regards, Cus

[bensherb]

Thanks Ben,
In the mean time I have scaled up this template, could you please check against your marks,

regards, Cus

I won't be home where the car is for another week but will check when I get home. It looks about right though. That's how I marked mine; with a degree wheel. I also did the math to check it. Measure the diameter of the disk, multiply it by pi, this will give you the circumference, then divide that by 360 to get the distance for one degree. I marked it in 5 degree increments because it's easier to mark, and see ,especially with a timing light, and for most things you can "guesstimate" if you want to go in between.