[Fred K-OR]

No it is not "knock, knock-whose there?" but rather where does this knock come from.

My 29 coupe has a knock! It seems like it knocks every time a piston fires. It is a kind of "hard" knock. It is there at an idle, still there when the engine speeds up a bit. Has just about the same knock with the spark lever either up or down. Do not seem to notices it when running at normal driving speeds. When I short out each cylinder, it does not change the knock. I have adjustable valves. It seems to be getting louder as time goes on. I run 10-30 oil in it and now days it is around 100 degrees here in good old rainy Oregon.

Questions-could it be a valve that needs adjusting? Is it a rod bearing? Is it a main bearing? Is it the timing gear? Is it the crank going back and forth? Or what??????

Any ideas would be appreciated. Don't have much experience with this type of thing.