L-134 stuck valves

Brumbach · Post by **Brumbach** » Fri Mar 25, 2016 7:20 am

Approximately 40 years ago, I "barned" my M38. It was running at the time with no issues. Well, it's out of the barn now and I'm beginning a full restoration. I wished I'd taken the time to condition things before storing, such as pickling the engine. Oh well... The majority of valves are stuck. The rotating assembly rotates easily until the cam lobes encounter the stuck valve(s). Most of the valves are frozen in the closed position. A couple in the open position. Two valves are free. Aside from treating with heat and penetrating oil, can you think of other ways to free up the stuck valves?

Thanks in advance,

Bill

4x4M38 · Post by **4x4M38** » Fri Mar 25, 2016 7:32 am

Is it rust Bill or old gunk?

Post by **wesk** » Fri Mar 25, 2016 8:15 am

Most cases it's dry guides and rusty or lead coated stems. What needs to be done next depends on your definition of "beginning a full restoration"

In most full restorations the engine gets restored along with the jeep.

If this is the case then pull the engine disassemble it for overhaul. Use a brass punch to knock the offended valves loose after the cam is removed.
In this case it would be a waste of valuable human life time to waste it on freeing stuck valves just to hear it run before the teardown.

On the other hand if you aren't really doing a full restoration then you are back to heat and penetrant and tapping on the valve stem with a brass punch. Start by pulling the head. This will allow you access to the top of the valves. Now you can build a small dam around the heads of the valves using anything handy with duct tape. Now you can puddle penetrant on top of the valve so it can seep downhill. Some valves you thought were closed will actually be cracked open. Now you have the option of prying them loose or trying to tap down & up to break them loose.

Brumbach · Post by **Brumbach** » Fri Mar 25, 2016 8:39 am

The engine is pulled and on a stand, partially disassembled. I'll be pulling the crank and cam next. Essentially, I'm stripping the block for cleaning, honing or boring, etc. The more work I do, the less the machine shop has to do. Should the cam slide out with the valves stuck in a closed position? Possibly, rotating it as I pull it out?

Post by **wesk** » Fri Mar 25, 2016 9:12 am

It should. But if it catches at some point you should be able to leverage any stuck valves up so the lifter can move up. I assume you have removed all the valve springs.

Brumbach · Post by **Brumbach** » Fri Mar 25, 2016 9:37 am

Not yet. Trying to uncover my spring compressor that's buried in my basement somewhere. I usually have two of everything because I can never find the original when I need it. One of these days I'll get organized.

charlesfitton · Post by **charlesfitton** » Sat Mar 26, 2016 8:22 am

Should the cam slide out with the valves stuck in a closed position? Possibly, rotating it as I pull it out?

If you are concerned at all, back off the adjusters first...

Brumbach · Post by **Brumbach** » Sat Mar 26, 2016 6:23 pm

Wouldn't rotate enough to back out the cam. I'll lower the adjuster and try that. Thanks