Cupped lifter on my 392.....

[Erik Socha]

Just got the news from the guy who is working on my wagonmaster. He told me that he found one of the valves stuck in a closed position. Upon further investigation he learned that the lifter associated with this valve is badly cupped. I was told that they motor needs a rebuild. However, at this time my wallet can not afford the rebuild.

I am thinking that the cam shaft might be toast, due to the lifter.

I was wondering if the lifter and the cam were replaced this would only be a band aid fix until I could afford the entire rebuild.

Anyways what would cause this "cupping " of the valve????

The photo below shows the "cupped" lifter on the right hand side.

 

[Robert Kenney]

I would not jump to a rebuild from a flat lifter. The other lifter in your picture looks ok so the rest of the engine is probably ok.

Can you tell if it had good oil pressure? Did it use oil of have any mechanical knocking other that valve/lifter noise?

If it were mine I'd slip a new cam in it and see what you have. If you rebuild down the road you would need a cam anyway. So keep the lifter order and reuse the new one.

Can you do the work your self? While you have it apart have a look at the cam bearings with a flash light and telescoping mirror. Check the valves for sticking and for bent push rods. Service your rocker assemblies too while you are at it. This will save you from grief down the road.

 

[Michael Mayben]

My opinion...if a valve was stuck ya gotta non-oiler motor. And it's not just because of a grunged up rocker assembly,...it's the I-4/sv crapped cam bearing syndrome.

If you pull the cam and look down the cam bearing bores from the front with the engine still in the truck, you will easily be able to visually determine the condition of the cam bearings using a strong light.

Then, if the stuck valve was on the passenger side bank, the bearing to concentrate on is #4. If the stucker is on the driver side bank, then concentrate on bearing #2.

If...the rest of the motor is in decent shape and it was a driver this long since ya got it, then I'd have no problem with poppin' the motor out and replacing only the cam bearings without tearing the whole unit down. Do not remove the heads/intake. Remove the pan and clean it out (bearing material will be found), replace front and rear crank seals ya need to buy only a "bottom end" gasket set and the seals are included. And disassemble/clean the rocker assemblies. The stuck valve will free up with a bit of coercion.

My reasoning here is because of the stuck valve, that is from poor/non-lubrication of the "feeder" rocker assembly, that is the only way a valve stem can lubricate. If ya just found a crapped lifter (fairly common) and a flat cam, I'd second Robert's analysis. But that valve has been hanging for many miles and has exerted a major additional force on that particular lifter/cam lobe interface. It's obvious that if the rest of the cam lobes/lifters are ok, that the entire lifter gallery was oiling or the noise would have been tremendous because all lifters would have been collapsed.

A sixpack sez...the stuck valve is on the passenger bank, either cylinder #2 or #4. How close did I guess?

 

[Brendan Barnes]

This engine was brought to my shop non-running. Under the valve covers, the engine looks pretty clean and all 8 cylinders compression test out well. Oil pressure is unknown.

The stuck valve was the exhaust on #4 cylinder, so its on the passenger side.

The other lifter in the picture is not a lifter in this engine. Just a good lifter for comparison to show erik when I emailed him.

As of yet, I have not pulled any other lifters to check their condition. Im going to tear into the engine a little more this week and see whether or not putting a new cam May be an option. Im afraid its a non-oiler engine, ive been down this road before with sv engines.

 

[Michael Mayben]

Thanks for shedding more light on eric's issue brendan!

We have by far, the most in-depth resources for diagnosing and correcting non-oiler IH motors right here in this sub-forum. We welcome additional input and observations from other professionals who have delt with loss of lubrication to the I-4 and sv sub-systems in the past. We've put a tremendous amount of research into this subject but we May never have all the bases covered.

Eric's wagonmaster is certainly a "special" vehicle in my eyes and needs to be treated inna manner which will preserve it's unique character in the production history of ihc!

I personally have spent hours of sv engine runtime waiting and observing for the glitch in the lubrication system to exhibit itself. This is not something that is a quick and easy diagnostic process. But once it happens (the slowdown in rocker assembly oiling can evolve over thirty minutes or more), it's simple to understand what the root cause of failure is...you can actually watch the cylinder affected drop out as the valve first tries to intermittently stick as lube diminishes, then all of a sudden...bingo...it tries to spit a pushrod and the lifter starts clackin'!

So many of these engines simply get a pushrod replaced and maybe a lifter due to the diagnosis..."bad lifter"...then the engine goes away for a few hours and the cycle repeats itself. The cam bearing(s) don't take a dump all of a sudden, deterioration occurs over time.