Flew the Coupe! – Part 16 – A stuck valve and the rope trick!

Woodstock misbehaves!

Woodstock was now a three cylinder airplane.  This was the third time Woodstock had a stuck valve that I know of.  Just before I was heading down to inspect the plane the fellows selling it let me know it had a stuck valve and they were fixing it.  Here is a photo they sent me:

IMG_0383

After the first leg of the ferry flight from Compton to Seattle Dennie found that Woodstock had a stuck valve again.  That was in Bishop California.  Dennie found a local mechanic that unstuck the valve for $100.

Now I had a stuck valve again!  So I needed to find a mechanic.  There is a place at Auburn airport that called Cornerstone Aviation.  Greg is the mechanic there and I set up an appointment for him to sort it out.

So the day of the appointment arrived.  Greg quickly confirmed that it seemed to be a stuck valve.  I helped him take part of the cowling off to get access to the engine.  He figured out what cylinder it seemed to be.  And preceded to removed the spark plugs,  the valve covers of both cylinders on the passenger side of the engine and some baffling.  This seemed to be the same valve all three times it stuck.

Here is Woodstock stripped of those parts:

IMG_20170908_111418

Greg removed the valve spring and retainer of the valve that was stuck open.  He then removed the rocker arm pin.  Now it was time for the “rope trick”!

The Rope Trick

Greg pushed in some rope into the cylinder and using the prop to move the piston up pushed the valve closed.  This valve was very stuck!  He used some emery cloth to clean up the exposed part of the valve stem.  He then tried a small piece of cotton thread to the valve stem and tried to push the valve back into the cylinder.  It was really stuck!!  He had to tap it into the cylinder with a small mallet and a punch!  He then used a reamer attachment on an electric drill to try and clean up the guide.  He used that for some time and then went to pull the valve back into the guide. The he used the rope again to push it back closed.  It was still very stuck!

He needed to repeat this process several times.  Several times the thread broke and he needed to manipulate the valve through the spark plug holes to get the valve back in the guide.  After three more times repeating this process the valve finally moved freely in the guide.  Then it was time to put it all back together.

Well, not so easy!  We needed to get the rocker valve pin back but the valve lifters wouldn’t collapse.  So the pin was in tension and would not freely move!  Greg and I ended up having to lever and us a mallet and small punch to tap the pin back in place.  But we got it back.  Then Greg screwed the valve covers back and replaced the baffling.  He put the spark plugs back in and we lifted the rest of the cowling back in place.  A few more screws and Woodstock was back together!  Greg made an entry in my engine logbook and let me know he’d bill me.  A couple of weeks later I got a bill for $280.

I was heading off to the Reno Air Races so I didn’t have time to run the plane or test fly it.  I got back from the air races but I had some things related to finding a new job to do.  I did finally get out to the airport and ran Woodstock.  The engine ran on all cylinders but I thought there was a  new rattle.  So I didn’t fly it. I will go back out there soon and check everything around the engine to make sure everything is properly attached.

Questions remain!

So I am faced with some serious questions.  Are there other valve close to sticking?  Should I be doing something to prevent this from happening again.  Some folks swear you should add Marvel Mystery Oil to your oil, or gas, or both!  Other folks say that won’t help.  I am wondering if I should just have the same process done to the other exhaust valves?  If I was working I’d just pay to have the other valve guides cleaned up too.  But should I just worry about the exhaust valves?  I did dodge a bullet.  It happened to me on the ground at my home airport.  And the valve stuck open so it should not have damaged any other parts of the valve train.  But but could have been much worse!

This entry was posted in Aviation, Creativity, Entertainment, flying, Musings and tagged . Bookmark the permalink.

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