Unhappy exhaust valve in front mid cyl #3

[n86121]

On a trip to Florida with "La Wife"
about 10 mins after a normal takeoff I noted a subtle vibration.

Being the reflective mathematical sort I made the following calculations:

To keep things simple, assume 2400 RPM
Divide by that's 40 rotations per sec
4 stroke engines take 4 strokes to produce on power pulse
Or about 10 power pulses per sec from each cylinder

The vibration 'felt' around 10 hz,
suggesting one cylinder unhappy somewhere.

To land, or continue, hmmmm.

Then, after maybe 10-15 mins it cleared up.

----

Now comes my annual "wallet-ectomy"

#3 cylinder, front engine, passenger side... 20 PSI. WHAT?
Borescope shows attached image for its exhaust valve.

So sad...

As you can see the valve is NOT rotating, and 20 PSI it is not closing all the way.

My gurus here tell me
The vale NOT rotating as it should,
'green edges' are from severe over-temp, aka a 'burnt offerings'

While one might be able to lap in place and pretty it all up,
the metal is cooked and WILL fracture at some point.

Sigh...

My options were
1. Have it pulled, send to shop, change vale, pretty all up and return to service $1.2k
2. Overhauled cylinder if available $1.6k - but not available!
3. Buy new $2.3k - available same day shipping

For time and value I bought a brand spanking new cylinder.
I figured project would go faster if kit IN hand.
And, I will keep the one coming off to have on hand if I need to OH it later.

==========

QUESTION: Mine is a turbo RSTOL = Pile 'o crap on each engine.
All that stuff is top notch great shape, but there a lot of it.

I can't complain. It is a factory new engine back in 1998 w only 600 hrs on it.
I don't fly a LOT, but do so regularly.

QUESTION 1

Any ballpark idea of how many hours to remove/replace a mid cylinder like this?
It looks like a royal pain aux derriere.

QUESTION 2

Am I over reacting? Should I just have had it lapped / ground in place to see what happens?

Your feedback, comments, reassurances and sympathies will be appreciated.

[mshac]

My guess is 8-10 hours.

There's a cylinder shop near me that will IRAN a cylinder for pretty cheap. Usually around $500 and comes back looking new. Maybe have your old one done so it can sit on the shelf as a spare?

[mshac]

Here's two rebuilt cylinders near me for $800 each. Sounds like a great deal.

They're done by Gibson, that's the shop I was referring to in my previous post: https://dallas.craigslist.org/ftw/av...696551439.html

If the old boy doesn't want to ship, I can pick them up for you and ship them to you (at your expense).

[Frank Benvin]

Ad says Lycoming ??? - 337'S have continental's

Originally Posted by mshac

Here's two rebuilt cylinders near me for $800 each. Sounds like a great deal.

They're done by Gibson, that's the shop I was referring to in my previous post: https://dallas.craigslist.org/ftw/av...696551439.html

If the old boy doesn't want to ship, I can pick them up for you and ship them to you (at your expense).

[mshac]

I missed that being in a hurry. Thanks.

Here are some Continentals: 8 cylinders, 3 of which are chrome overhauls loaded and ready to go, one broken OH cylinder (use the parts to load another cylinder), the others are bare cylinders $1750 for everything: https://www.ebay.com/itm/255454370492

Says to "contact him for a better price" so I bet you could get it for $1500. If someone wanted to go in on something like this, I'd be a player. I'd love to have a spare OH sitting on the shelf. Turns out IO-360 and TSIO-360 use the same heads, same p/n and all.

[Frank Benvin]

Make sure you get the right Cylinder for your engine

You can confirm using continetal's website by entering the part # of the cylinder to see if it fits or your engine information to get the part # of the cylinder for your engine

https://continental.aero/support/ill...s-catalog.aspx