The Stovebolt Site Forums The Shop Area Engine Shop Noisy 235 lifter(s)

The '61 235 we rebuilt and installed in our '52 AD five-window has run very well for the first 2K miles. We had it appart over winter to install a MustangII front end, disk brakes, R&P steering, etc. While the engine was out, I did the little relief grind on the number one exhaust lifter because it would get noisy from time to time, and now its quiet. But, lately when driven at highway speeds, it develops a noisey lifter on either number 4 or 5, but I can't tell which because after it has stopped for awhile, and is restarted, the noise is gone! Should I pull all the lifters and grind the relief air bleed? Is it possible the oil is getting aerated and the lifter can't expell the air? Any suggestions? Should I put heavier oil in it? It has 10-30 in it now, would going to 20-50 help?

I ground one offensive lifter and it did the trick. This was suggested to me by Tom Langdon who says this was done on all lifters of a certain model engine at the factory. It was his idea but he gave me credit for it on Inliners tech tip page. I imagine there would be no harm in doing both 4 and 5, personally I would do no more than you have to as each one you do will result in slightly lower oil pressure. I would have the valve cover bolts loose and jump out with a hose to listen after your next highway run.

Yes, the noise is from airated oil. I assume you already checked for air leaks on the suction side of your oil pump. At highway speeds the condition gets worse and after it returns to idle you only have a couple minutes to find the offensive lifter(s). The clearance you grind is a path for the air to escape without going into the lifter. Lifters don't like air.