The Stovebolt Site Forums The Shop Area Engine Shop Hydraulic Lifters, Different Lengths of Adjustment?

Slowly moving toward a test start of the '54 235 engine in my project 1940 pickup.

Adjusted the valves last evening using the "companion cylinder" method suggested by Hot Rod Lincoln.

When I finished, I realized that the adjustment of some of the screws was significantly different than on some of the others. I have never done this before, and I would have thought that all the valves would use close to the same amount of threads.

To my knowledge, this engine has not been run in years.

I just figured that I would ask before I started cranking the engine, in case the difference of several threads showing on one cylinder and only a couple on another was an indication that something was wrong.

Are pushrods all the same legnth?

I never considered that they might be of different lengths.

I was making the assumption that the engine had all the same length pushrods in it when I got it. They all seemed to be straight when they were loosened up and spun with my fingers, but I didn't pull them out to measure or check them one against another. (They also looked fine when I had the side pushrod cover off.)

There are at least two different lengths of stovebolt pushrods, depending on the style of lifter used. The "milk can" lifter uses a shorter pushrod than the later style, more conventional looking type, and there's also a 1/8" difference in the height of a 216 and a 235 engine block. I'm not sure if 216 and 235 engines run different length pushrods. I'd suggest starting over by measuring the pushrods. Did you ever figure out if you're working with hydraulic lifters or solids? The adjustment procedure is totally different, although the companion cylinder procedure can be used for both types. Have you considered that the cam lobe under the pushrod on that cylinder with the oddball adjuster height might be worn out?
Jerry

You could tap on the valves with a rubber mallet to see if the one is stuck and not closing all of the way if the pushrods are all the same length.

One of the first things that was suggested to me when I started on this project was to tap on the valves to ensure that none of them was stuck. I did that and they all appeared to move as it seemed that they should.

I did remove the side cover of he engine trying to learn two things. One was to see if it had hydraulic lifters (it does) and the other was to see if it was clean enough to believe that any of the "story" that came with this engine was realistic. (I was told when I bought the project that the engine was a crate engine. I immediately decided to consider that, if the engine was in good shape, (at best) I would consider it was probably rebuilt. The head and the block have the same late 1953 date cast into them.) The oil is very clean and some who know more than I do have said that it looks like break-in oil to them.

So, my next question is, even if the pushrods are of different lengths, if the valves are adjusted properly for whatever length the pushrods are, would there be a reason for the engine not to run properly?

Did they taste the oil?
I don't know of any way (especially by sight) of determining what kind of oil it is. Just saying.

On pushrod length, it looks like there are quite a few different lengths. Per the attached clip from the 1929-1957 parts catalog.

If they are hydronic lifters could there be a chance that the lifter has leaked all the oil out and therefore needed more adjustment.That one lifter that shows more adjustment may have to be loosened to allow it to fill with oil or does it have to be filled with oil before adjusted ,I don’t know much about those lifters but I would not run it like that until you look into it more.

Sun Electric Company used to put a slogan on all their test equipment- - - -"We Test Not Guess". When something going wrong is as obvious as what's shown in that picture, it's time to start all over and do a complete forensic examination of all the possibilities. This is a really good example of why I'm extremely reluctant to even think about using hydraulic lifters in a stovebolt engine. The technology back then was just not up to the job at hand!
Jerry

The engine in question came from the factory with hydraulic lifters, per the stamped serial number on the engine.

I will remove and measure the pushrods and make sure that they are all the same length. It appears that they should be 11 1/4" long from what I can find. (Confused a bit by what appear to be conflicting statements in the Master Parts Catalog.)

Jerry, I saw a post recently where you suggested pre-filling the lifters by spinning the oil pump while turning the crank a few revolutions. I will do that in case some of the differences apparent in the adjustment screws is due to the engine sitting for an extended period.

The internal springs inside the lifters should keep the plungers topped out against the retaining rings. Sometimes I've found that it's necessary to be able to see the plunger while you're making the adjustment or it's possible to force it all the way to the bottom of its travel. The internal spring is very weak. That's easy to do on a V8 engine with the intake manifold removed, but it would require pulling the side cover on a six. A 20 thread per inch adjusting screw will only move the pushrod down .050" in one turn, so the inner plunger is usually less than 1/16" below the retaining ring when it's adjusted correctly. Non-adjustable rocker arms for V8s like those used on Pontiac, Oldsmobile, Ford, etc. require different length pushrods to adjust lifter preload, usually +/- .050"
Jerry

Good info, thanks!