Pushrod selection

Well, I thought I had it but………

My noise above 2000 rpm came back, probably worse than ever. I have not updated this thread for a while probably because I was embarrassed more than anything. I obviously did not realize how much I don’t know!

I first adjusted my preload at ¾ of a turn when I installed my adjustable rockers, so then I tried it at 1 full turn. The noise was worse. Then I tried 1/2 a turn and it was no better. A ¼ turn was no better. The entire time it is making more and more noise. It can’t be the pushrod length causing the issue. I even gave it a try with the old stock non adjustables again. That was the worst it’s been. Getting desparate I checked the convertor bolts as was suggested but all was good there.

So not knowing what to do, I pulled the heads, checked the valves, nothing sticking or anything, no valves touching pistons or anything crazy like that. It was a ***** of a job and a complete waste of time. When I put it all back together still not finding a smoking gun of any kind I consulted with @oldkimmer on the phone. We discussed the possibility of oil to the top end and orientation of the rocker shafts. I made sure the rocker shafts were in correctly, adjusted the preload to ½ turn after zero lash and started it up again. All sounded good for a couple minutes then a loud Tick-Tick-Tick was coming from the drivers side valve cover. Passenger side was quiet. I used a long screw driver to my ear to locate the sound. Well damn! That’s a new one!

So I pulled the drivers side valve cover off and one lifter seemed squishy as hell and the others seemed firm. Hah! A bad lifter! So I changed that lifter, put it all back together but it made no difference. I hated the sounds it was making during that lifter break in but I was pissed off and I let it eat! it was quiet at idle after the lifter I should mention that through all of this, oil pressure has been between 20 at idle when warm to 50 at 2000 rpm plus.

I guess next, I’ll pull the rocker shafts once again and see what I have for oil getting to the top end. The plan is to pull the distributor and drive shaft then run the pump with my priming shaft. I know I’ll have to turn the motor over some to get oil where I need it.

Is it possible that the stock replacement lifters I used cannot handle the pressure of the valve springs and cam I have? Unfortunately I don’t have the specs on them but I believe the springs must be decently stiff because I have never floated the valves on this engine. It hits 6000 rpm at the track, or it used to!

I see there are some really smart guys following this thread, so I am hoping for some advice!



Cley