Re: Finding the compression stroke

[Christopher Eveland <eveland@domain.elided>]

> The best tool I know of, Michael, to check TDC, is to take a spark
> plug, break all the porcelain out of it, JB weld a piece of tubing
> into the steel part, and hook a piece of plastic or rubber tubing to
> this and out into a glass of water. The firing upstroke will produce a
> string of bubbles in the water, and as soon as you get no more
> bubbles, you are within a few degrees of TDC. No, the down stroke
> won't suck the water back in because one or the other of the valves
> are open.

In the power stroke the piston will be going down, and there aren't any
valves open, so it seems to me it would suck the water back in.

Aomething you can do to avoid making such a contraption anyway, is to
just remove the spark plus and use your finger to feel the air coming
out under compression.  Sure it won't get you to within 1 degree of TDC,
but it will get you close enough that you know that the timing mark is
TDC of comrpression rather than exhaust.

If you take the valve cover off, you can watch the rockers and figure it
out as well.

-Chris
'67 800