FUNDING TDC

[petep]

Been doing it the old way by feeling for the piston travel. It definately leaves some room for interpertation. Does anyone have a more accurate way of finding TDC?

[daleandee]

Been doing it the old way by feeling for the piston travel. It definately leaves some room for interpertation. Does anyone have a more accurate way of finding TDC?

You don't say which engine you are working on.

I have a Corvair conversion. By removing the spark plug I can look in with a bright flashlight and see the piston coming up. When coming up it's either on compression or exhaust stroke. Placing a finger over the hole and feeling pressure building proves the it's on the compression stroke. I watch the piston carefully as it comes up, stops, and begins downward. I can get very close to center travel (and do so when doing differential compression testing).
I also have timing marks on my harmonic balancer (which your engine may not have).

Another feature of my engine (by WW design) is that with the oil fill cap off you can see the valves of the # 1 cylinder through the fill tube to see if both are closed proving that it is on the compression stroke.

On the Aerovee I used to own I could look through the oil fill hole with a bright light and see the timing marks on the crank & cam.

Dunno if this helps ...

Dale
3.0 Corvair/Tailwheel

[Area 51%]

Depends on how fussy you really need to be.
You can get a cheap dial indicator at Harbor Freight. .