What is the proper way to adjust the tappets on a 1950 pan equipped with the OEM hydraulic pushrods? I know that 4 full turns is right for the later , hydraulic lifters/solid pushrods. For my bike, with the early hydraulic pushrods/oem lifters,should I adjust them 3 turns OR do I just adjust them so that the pushrod spins freely and has no up/down movement?

 

If those are the stock hyd push rods the bulge at the top of the rod get rid of them better yet frame them go to adj solid push rods Are your adjusters (for pushrods) coming out of the lifter bases?

 

Engine must be cold.

Remove pushrod cover keepers and telescope covers to expose tappets.

Before adjusting tappet, make sure it is at its lowest position. You can make sure by turning engine in the direction in which it runs until the like tappet (intake, exhaust) in the other cylinder is at itd highest position (valve fully open)

Loosen tappet adjusting screw lock nut and turn down until push rod is free and has noticeable shake. When checking for push rod shake, grasp push rod with fingertips just below cylinder head, and shake toward front and rear of engine.

Slowly turn tappet screw upward just far enough to take up all push rod shake. Now mark tappet screw with chalk or some other manner, so its turns can be accurately counted, and then continue turning upward exactly three full turns.

Adjust the other three tappets the same way.

With tappets accurately adjusted, hydraulic units will be compressed 3/32", which is specified for normal functioning.

If after adjustment, engine does not start readily because of loss of compression in one or both cylinders, allow engine to stand for a few minutes before further attempt to start. This standing time is required to allow newly adjusted hydraulic units time to leak down until valves are fully seated.

Bear in mind that after intial adjustmetn as described, hydraulic type pushrods are self adjusting to compensate for hot engine expansion and valve mechanism wear. Therefore tappet adjustment is normally required only in new engine assembly and when engine is reassembled after having been taken apart for repair.

That being said...bear in mind that there is a reason that MoCo changed form topside hydraulics to bottom side in 53...it was a very poor design and resulted in collapsed lifter problems.

My 49 EL came with hydraulics. I am close to starting the reassembly and will use solids with a lot less to worry about. Best of luck to you doc.

 

bottom line get rid of them Thank you very much

 

Thanks very much, guys.