A old timer taught me a trick over 35years ago on how to find a leak in the cylinders. Rig up a fitting to air up the cylinders with a air compessor. I used an old non fouler spark plug fitting and screw a mail air chuck fitting into it then pluged my air hose right to the air chuck fitting., This located many problems for me over the years. I've found blown head gaskets between cylinders, bent valves, cracked heads and blocks, air coming out of the radiator neck that indicated a leak from the cylinder your checking into the water jacket. Man it works!
