Turning to the Jedi for thoughts..... I have a recently rebuilt engine, all new...89mm pistons/jugs, main & rod bearings, wrist pins, oil pump innards, distributor pedestal bushing, crank turned 10 under, 270 cam w new cam bearings, new timing chain and sprockets, push rods, tappets and rebuilt rocker assembly (not rollers).. if I could find it I replaced it. I'm chasing a tapping noise that seems to be coming from the distributor/oil pump area. Steady, fast tapping that will disappear at 1500 to 2000 rpm. Distributor was mounted with end play determined using washer method in manual (yes, washer was removed after calculation)...needed a .004 paper gasket to achieve desire clearances. I've found that if I loosen the distributor pedestal and shim the pedestal .100 (yes that is a lot)on the outboard side (pushing it inboard - toward the block) the noise is all but eliminated. With the shim in place it sometimes taps (almost a rattle) for a second or two at start up and shut down....but other than that no unusual noise. Compression is good and even in all cylinders, have pulled plug wires to check for changes..none noted. Exchanged distributor..no change. Exchanged pedestal...no change. Exchanged distro drive gear...no change. Have removed fan belt...no change. Valves have been adjusted...checked and rechecked. Engine runs strong with no unusual noise under load. New cam/old drive gear....but no evidence of unusual wear on gear. Stethoscope inspection indicates sound from distro pedestal area. Definitely loudest at base. Nothing uusual noted at timing cover or high on distributor itself. Have visually inspected valve train while running with valve cover removed.....all oiling well, nothing remarkable noted. Dropped sump, inspected for interference, took a look at inners of oil pump, noting obvious
I suspect some issue with distributor drive gear/cam gear lash up or issue in oil pump or drive shaft. But I am out of ideas....turning to the Masters for your thoughts....hoping one of you may have faced a similar issue.
I suspect some issue with distributor drive gear/cam gear lash up or issue in oil pump or drive shaft. But I am out of ideas....turning to the Masters for your thoughts....hoping one of you may have faced a similar issue.