miyu1975

miyu1975

Well Known Member
So I have experienced on few occasions that meet every indication of a sticky exhaust valve on number 4 of my angle valve 360. It first appeared at Oshkosh, then reappeared in the last month or so. Now that it's reappeared it has been eating at me an I'm afraid to fly until it's checked and reamed. I have read every service bulletin, service letter, online write up ect....describing the process of dropping the valve and reaming the guide, til I'm blue in the face. Not doing anything like this before I finanlly reached out to an "ol timer" a/p who said he would help me. But he said the only way is to remove the cylinder. I told him about doing it cylinder on and said no way to do it correctly. So...do I go ahead and let him help me remove the cylinder, which is unnecessary, or find another a/p for assistance.
 
Maybe RocketBob will weigh in here, but here goes. If the job can not truly be done without removal of the cylinder, and you/he have the tools for reassembly. It is a simple removal and reassembly. The only cost difference are the gaskets, and there is a very small risk of ring breakage with any cylinder install. I would not hesitate to do it this way.

You should discuss with your A/P what is "right" about the cylinder removal vs doing in cylinder, and satisfy yourself to the differences.

I love seeing inside the engines and gaining confidence with it's condition, but that's just me. :D
 
I had this same issue a long while back, same engine. I followed the lycoming sb. I did not remove the cylinder. First of all, you can check the valve and determine if you have an issue without removing the cylinder. Reaming the guide insitu is easy. I would have someone who has done it before get you started, or assist you in performing the operation. It is not difficult! You need a ream and a valve spring compressor, so find someone who has the tools and get started!
 
Its a very common and "normal" process on the smaller Continentals. I have performed it many times (I'm an AP/IA), and never had negative results. I cant speak for your exact situation, but the process is designed to "clean ream" deposits from the guide. Its weird the first time the valve drops into the cylinder, but mechanical fingers, and a flashlight and its right back in. I usually use compressed air blowing into the cylinder while reaming to help keep debris minimized.
 
Removing the cylinder is a positively known way to get the valve issue fixed plus it gives you the opportunity to inspect some of your cam lobes as well.
 
I guess my biggest beef in removing the cylinder is the several hours it will take to remove my baffles.

Have not done the wobble chck but I figure that will be done prior to dropping the valve. I do have a compression spring tool but no reamer. I called lycoming tech support and they told me I would need .4995 to .5005 to the finish id. I have found several sources online to buy such reamer.
 
Don't know what your symptoms are but if the problem eases upon warming up, you might try changing the spark plug, if you're using Champions. One gave me indications that looked like a sticking valve that went away after getting the engine warm. Installed a new plug and it's been fine.

Dave
 
The Lycoming procedure is described in their service instruction ( http://www.lycoming.com/Portals/0/t... Reduce the Possibility of Valve Sticking.pdf )

If I had a choice and could avoid pulling the cylinder, I would not pull it off. On the other hand, if there was time enough on the engine that I could get a look inside and it would be meaningful to do so, then I would. The Lycoming service instruction for installation of the cylinders, I believe, was 1029 - I'd have to check to see what the latest version of that would be.

Dan
 
I would read some of Mike Busch's articles on cylinder removal before doing so. Too many people treat cylinder removal as an out-patient operation, when it is really major surgery. There is no reason to be afraid of it, but it needs to be done properly from start to finish.
 
i have a schedule to have my rv done this tuesday. ill post some pics and info after it is done. the engine is mid time.

the r44 io540 was done last month and found 2 tight guides. also a mid time engine. it was fun watching the less experienced mechanic trying to finesse the valve back into the guide.
 
Well I found another a\p to help me do the wobble test and ream if needed. Considering his day job is maintaining a P51 and Bearkat, I will do what he says. More to come next weekend.
 
pa38112 said:
I would read some of Mike Busch's articles on cylinder removal before doing so. Too many people treat cylinder removal as an out-patient operation, when it is really major surgery. There is no reason to be afraid of it, but it needs to be done properly from start to finish.
Click to expand...

mike has published articles indicating both to be the case (major surgery and out patient)

he contradicts himself quite a bit
 
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