Having the piston at TDC will tell you that it is either at exhaust or compression stroke, but by taking off the valve cover and observing the rockers you can tell the diff; compression stroke will have both valves closed, exhaust stroke only one valve closed. And please don't be sticking your finger into the hole. Cover the hole with your finger, use a dowel or spaghetti, a fancy TDC whistle or a good flashlight, but don't stick yer finger in there. All these suggestions from me and others are assuming everything else is in good shape, and that you are trying to adjust an engine with a jumped chain or bent/broken valve. Take the time to start from square one. An old Motors manual from the sixties will give you a guideline to static time the engine when we all kept our cars running from the shade of the old oak tree, without the benefit of all that big city equipment......Russ __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail