The Stovebolt Site Forums The Shop Area Engine Shop 235 Hydraulic Lifters

My 57 stepside still has a 235 (62 passenger car engine to convert to hydraulic lifters). You may recall the problems I had a few years ago with engine builders. I finally got it built by a speed shop and with one exception the engine seems to be fine. That exception is that the lifters seem to leak down after it sits awhile. They clatter for awhile until the pressure builds up again. I don't like the sound and can't help but wonder if that's doing any damage to my engine. I've tried different kinds of oils and I tried Lucas treatment but no luck.

So; why is this? Is it that the shop used some cheap replacement for the lifters? Is there a defect? I don't know; they aren't around anymore to ask. This is where you come in. Do you have a source for lifters that I can count on? You know; like the ones GM put in there originally? Thanks.

that's what hydros do when they sit for extended periods of time. but from what i've read, since it's of short duration, it's not doing harm. they can also pump up and cause other problems that do cause harm. and they're not for high perf/racing either. google them and see

How long does the engine need to sit before the lifters start to clatter on startup? A good hydraulic lifter should stay pumped up for a week or so without having to refill itself on the first start. Every time the engine stops, at least a few of the valves will be open, with valve spring pressure exerted on the lifter. It will slowly leak down- - - -nothing wrong with that, because otherwise the lifter could top out and hold the valve open the next time the engine starts. The problems start when the collapsed lifter takes a few seconds to refill. Other than being annoying, the noise isn't serious- - - - -UNLESS it goes on for a minute or so. A few clicks on a cold start after sitting idle for a day or more don't cause a problem. If it's taking several minutes to quiet down, you've got problems with either the check valves in the lifters, or very low oil pressure.
Jerry

Oil pressure at start (cold) is 60+ pounds. The lifters will clatter for a few blocks before they start to settle down.

I had some issues with lifters both at start and also after normal warm-up when I was running Rotella 15w-40. The problem was not with the oil but my choosing it!! A switch back to 10w-30 immediately corrected the issue.

You didn't mention what WEIGHT oil you were running but 60 psi cold oil pressure, especially with the cooler temperatures raises a red flag. If by chance you're running a heavier oil in hopes of getting a higher zinc/phosphorus concentration, I'd consider some lighter oil and adding a little Lucas ZDDP Break-in suppliment (not their oil treatment) just to be extra safe.
The oil treatment is a viscosity enhancer and you need to go the other way. I'd do this before I started replacing lifters.

Dave

I feel that on some new lifters the clearance between the plunger and the body is to tight. In this case, when the lifter bleeds down while sitting, the plunger sticks and is not released until the lifter warms up. In this case they seem to wear in and end up being OK.

on new builds I have had problems with some offshore crap lifters and valves among other things the lifter problems would not go away till we went to synthetic oil (amsiol V-twin 20/50 in fl) then the noise never came back. the valve problem was the stems would swell so much the valves would hang the only fix was to add clearance to the guides. Next time I will not be sold import crap again

I mis-spoke. When cold, the oil pressure is 30# on the orignal stock guage. At operating temp, it's down around 15#.

Hey Jerry-

If you have 30# at start cold and after warming up have 15#'s I would say that your fine in that area. I have a rebuilt 235 that is now 3-4 years old and still have 30 or a little more at cold start and around 15#s at idle after warming. I have also put 1,000's of miles on it, my odometer is broke so I don't know for sure, but it's a daily driver if that let's you know. After a week of sitting it will have leaked down, so I would say it's normal.

Thanks.