Lifter problems????

God, I hope not. But it appears my sub 2000 mile 360 is developing a lifter problem.

I recently changed from Castrol SAE30 to Amsoil 10W40 motor oil in the car. I waited over 1000 well driven miles before changing. A few weeks later I developed a tapping noise at startup if the car sat more than a day. I don't see how going to a heavier oil would cause anything, but I thought I'd put it out there.

NOW, after sitting 3 weeks while getting my cooling system ironed out, and my oil kit/cooler system on, I have still have tapping at startup if it sits more than 30 minutes, AND it has a constant valvetrain noise from one of the 2 right side back cylinders.

My friend thinks it might be a collapsed lifter. It's a stock rocker setup with cut down 400 pushrods and a mild 455/475 Doug Hebert cam. The motor has been together and in the car since 2001, but until this year it was only started and ran on a monthly basis. Since last november it has seen regular heavy footed street duty (no racing). It still seems to run great.

Oh yeah..it runs about 40psi of oil pressure when warmed up at anything over 1000 rpms. Below that it runs about 30-35. I have a new VDO electric oil pressure gauge.

Why would it fail now?
What causes this anyway?

I'm going to pull the valve cover off tomorrow to look at it. Is there a best way to determine what is going on? I'm going to check the rocker shaft bolts and lash on the rockers. I'm not sure what the engine builder had them set for, but I figure they should all be close.


I have faith in the builder. He came highly regarded by my car club. Unfortunately he passed away a few years ago.

A Little Help PLEASE!!!

Thanks