How can you tell hydraulic lifters from solid lifters in a running engine. This is a big block 1966 chevy.?

Question

We can't tell from looking at the top of the lifter thru the opening in the head. If we find they are solid lifters, anyone care to guess at the setting. Thank you.

Answer 1

Start the engine with one valve cover off. Loosen a rocker nut until you hear it start to make noise. Tighten the nut until the noise stops. Tighten the nut 3/4 of a turn more. If the engine is running smooth, you have hydraulic. If it isn't you have mechanical. Unless someone changed the cam, it's probably hydraulic. Only the 427 CI with 425 HP had solid lifters in 66. If it is a solid, hot adjustment is .020 for intake and .024 for exhaust according to my Chilton's.

Answer 2

put the valve covers back on and start the engine hold the gas pedal to the floor . if the lifters float and the engine misses they are hyd. if the engine makes a load bang! and stops at a high rpm they WERE probably solids. IF ITS RUNNING WHY DOES IT MATTER if your going to do some hp work on this engine you will have it apart any way .

Answer 3

If the lifters are hydraulic, they are not adjustable. Only solid ones are.

Answer 4

solid lifters tend to clatter alittle due to being set with .005-.007" clearence on the intake valves and .008-.012" clearence on the exhaust. hyd lifters a self adj to zero lash so the are quieter.

Answer 5

With the valve cover over simply press down on the push rod. if it yields it is hydraulic. If it is like a rock it is either broken or solid.

Answer 6

solid lifters have a distinct tapping sound. you should also see a lock nut and adjusting nut on the pushrod in the rocker arm. hydrolics will have a single nut holding the rocker arm to the head.