M-10 Timing

[starcruiser]

Cornishman,
The blocklayer site is great! You can measure the diameter of your pulley and then adjust the template to that size and print it out. Line up the TDC marks, tape it to the pulley, then mark the appropriate notches you need, 3 degrees BTDC and 25 degrees BTDC. I see also that can print out a tape to go around the circumference of the pulley and do the same procedure.
Thanks, Starcruiser

 

[zinz]

My ‘67 only has the front pulley marks and pointer. There is no window at the top of the bell housing as is most M10s. This was certainly a surprise to me when I got the car. That early 4 speed also does not have a synchronized 1st gear, so you will find that when coming to a stop, go to 3rd gear before putting it into 1st will keep it from “crunching”.

For me, a tune up begins with adjusting the valve lash. While I’m doing that, I’ll bring the engine to TDC, referencing the camshaft mark under the oil sprayer bar. Then I marked my front pulley with paint to make it easier to see in the strobe.

As for your two pulley marks... The engine rotates clockwise, the first mark in rotation would be the BTDC mark, the second mark should be TDC.

I’m away from my blue manuals, but I’ll try to post some pictures later.

You are correct to sort out your ignition before tweaking your carbs. One last note, if you see the timing mark “bounces” a lot in the timing light strobe, that indicates the distributor is worn and should be rebuilt. Another indicator of a badly worn dizzy is if there is excessive play, up and down, on the center shaft of the distributor. A badly worn distributor will result in poor running, especially at idle, and the lower revs.

Hope this helps, good luck!

Ed

 

[Drew20]

you can buy a timing light with a variable advance. Which means that you can set your timing advance to whatever you need it to be, just using a TDC mark. So you dial in 25 degs on your timing light and then align the TDC mark (ie zero degs advance) to the pointer and that will be 25 degs timing advance. (the timing light must delay the strobe flash by 25 degs somehow)
Of course you still need a reliable TDC mark on the flywheel, vibration damper, crank pulley or whatever

(I always paint the markers in tippex, FWIW)

good luck

 

[Drew20]

I’ll bring the engine to TDC, referencing the camshaft mark under the oil sprayer bar. Then I marked my front pulley with paint to make it easier to see in the strobe.

risk here is that chain stretch, a skim of the head, or just general wear may mean that TDC at the cam is not TDC at the crank.

With my E24 I checked TDC marks by sending compressed air into n0.1 cylinder through an adapted sparkplug and "balancing" the piston at TDC, ie at the point where the piston does not move, even with compressed air pushing it down, like a leak-down test in fact.