Timing TDC

[Lyndon302]

TDC to set my cam timing. Is the mark reliable on the pulley or should I use a wheel and the piston.
67 911
Lyndon

[Flat6pac]

I use the larger SC pulley to set TDC and cam timing.
As long as the pin hole in the crank isn’t worn open, I’ve seen it once, you should be good..
Cam timing numbers are a variable, TDC is not variable but dependent on your judgement.
Bruce

[Lyndon302]

Thanks. I will use the pulley.
I have some DC 30 cams. 3.5 mm
Quite different from a std setting
Lyndon

[targa72e]

When Assembling the engine I check pully accuracy for TDC by putting dial indicator on piston. Easy at that point to see if pully mark is off.

john

[Fever]

I use the Stomski digital tool with their tdc indicator, great stuff, very accurate.

['78 SC]

I photocopied some graph paper onto transparency film to make a cursor over the timing marks. The back edge butts up against the fan support to square it up and align the grid with the case. The shiny cylinder is a magnet stuck to the fan locating pin to hold everything in place.



I found this made the valve lift readings more consistent, especially when trying to match the left and right sides.

[E Sully]

For reference, here are the pulley markings for various years.

[Mark Henry]

Originally Posted by '78 SC

I photocopied some graph paper onto transparency film to make a cursor over the timing marks. The back edge butts up against the fan support to square it up and align the grid with the case. The shiny cylinder is a magnet stuck to the fan locating pin to hold everything in place.



I found this made the valve lift readings more consistent, especially when trying to match the left and right sides.

Good job!
But tell the rest of the story, because I do the same.

Looks like you transferred the lines to the rear pulley edge using a hacksaw blade cut and besides TDC and the valve timing marks you added some ignition timing marks.
I marked my pulley for 10, 28 and 32 degrees. You have done close to the same.

['78 SC]

Originally Posted by Mark Henry

Good job!
But tell the rest of the story, because I do the same.

Looks like you transferred the lines to the rear pulley edge using a hacksaw blade cut and besides TDC and the valve timing marks you added some ignition timing marks.
I marked my pulley for 10, 28 and 32 degrees. You have done close to the same.

Thanks, Mark.

The notches were in place when I got the car. Motor is an '82 but was raced, so who knows what has been modified.

I color coded the notches: green for geometry (0-120-240 degrees) and red for the ignition advance marks (appear to be roughly 5-30-40 degrees). Helps me keep it all straight when setting cams, adjusting valves, adjusting timing...