Is it time?

Update.

Plane left Madison, WI with 7qts of oil in the sump, after landing in Champaign, Ill the plane had 3 qts. So, it lost 4qts of oil in 1:15. According to my partner, the engine continued to run smooth and he felt no power loss. After landing the shop on field cut the filter, and found it to be clean. They checked the screen, and found pieces of ring in the screen. Based on #3 being low on EGT, they pulled #3 , and this is what the piston and ring pieces looked like.
 
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Cylinder supposedly looked very good (no pics), and the mechanic put a hone on the cylinder walls for the new piston and rings to seal, and put it together. My partner flew it home Saturday, no abnormal conditions noted and he said it ran and performed normally. He is doing another 2hr each way XC later this week, and will keep an eye on things.
 
Thanks for the update. You should mount that piston with pieces of the rings on a mahogany base and display it.
 
The piston itself doesn't look bad, other than the carbon build up. The ring lands might be a little opened up from the broken rings bouncing around in there. Little bit of wear on the edges of the piston crown. Good to hear the cylinder was in good shape. That saved you some $dough.
 
Is it harder to get angle valve cylinders? When looking at some shop web sites, they say rebuilds with parallel valve cylinders get new cylinders but angle valve versions get reman cylinders. Is this purely a pricing thing, angle valve cylinders are more expensive, or something else?
Angles valves only made by lycoming. $2500 vs $1000 for parallel.
 
It is only Time to overhaul when you think it is, every thing else is just numbers and opinions.
I'm overhauling a newly built m20c engine because I feel it's time. Runs great, good compressions but it has 2600 TTSN, never overhauled. New was 1966.
 
So, now we've had another engine issue, this time the intake valve head snapped off inside the #2 combustion chamber and beat hell out of the cylinder and piston head. This engine is at 22yrs and 2100hrs since overhaul, and this is now the second serious issue in less than a year. Luckily the valve failed on the ground and not in flight. So, I'm thinking it's time, pull the engine and overhaul. I'm waiting to see what the partner consensus is, but I guessing they'll elect to repair the cylinder and keep flying. I'm of the opinion that something else will again fail soon and we'll be nickel and dimed (AMUed?) to death keeping an old engine limping. Or worse, have one of these issues in the air. I'm ready to pass the hat and get'er done.

Bill Jennings
 
So, now we've had another engine issue, this time the intake valve head snapped off inside the #2 combustion chamber and beat hell out of the cylinder and piston head. This engine is at 22yrs and 2100hrs since overhaul, and this is now the second serious issue in less than a year. Luckily the valve failed on the ground and not in flight. So, I'm thinking it's time, pull the engine and overhaul. I'm waiting to see what the partner consensus is, but I guessing they'll elect to repair the cylinder and keep flying. I'm of the opinion that something else will again fail soon and we'll be nickel and dimed (AMUed?) to death keeping an old engine limping. Or worse, have one of these issues in the air. I'm ready to pass the hat and get'er done.

Bill Jennings

Intake valves don’t normally fail, pretty unusual failure to base an overhaul decision on. I’d keep going.

Paul
 
Angles valves only made by lycoming. $2500 vs $1000 for parallel.

Continental/ECi/Titan started making angle valve cylinders last fall, a couple of months before your observation. Yup, they’re less expensive than Lycoming’s!

Paul
 
I’d say it’s time. Either now or later.
 
that's just cause u fly with him lol.
Ha, I mean not necessarily, because I know the drudgery of having your engine in the shop for 6+ months. But having two impactful events in less than a year might just be the engine telling you something. What’s the A&P say?
 
What's that mean, now or later? Which is it, now, or later? Which is your preference? Eh?
It means that you either OH it now (which is inevitable at some point) and get it out of the way, or continue to patch it until it requires a mandatory OH further down the road. As we know it’s a crap shoot either way, so you just have to go with your gut feeling—and whatever the A&P says about it.

Of course it’s just my 2c which is meaningless.
 
Continental/ECi/Titan started making angle valve cylinders last fall, a couple of months before your observation. Yup, they’re less expensive than Lycoming’s!

Paul

Got a link? I’m in need of a set of angle valve cylinders. I hadn’t heard of this yet.
 
IMO, if there's nothing wrong with the bottom end, there's no reason to overhaul. Grab a used cylinder from somewhere if necessary, and keep 'er going.
 
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