Cylinder video wanted

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
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Anyone seen details on how they install valve seats into aircraft cylinders?
Could not find on YT.
 
I would take a verbal description even.
Just wondering what holds them in, how they are inserted & removed.
 
Why would this be any different than an automotive or motorcycle cylinder head? There is plenty of information on the process for those.
 
I forget what they call it. But isn’t that one of those things that they heat the cylinder and put the valve seat in the freezer for awhile? Press the cold seat in and let the temperatures stabilize?
 
Let'sgoflying! said:
I would take a verbal description even.
Just wondering what holds them in, how they are inserted & removed.
Click to expand...

The parts are milled to close tolerances, the cylinder is then heated to very high temperature in an oven, the seat installed and the contraction of the metal after cooling holds it in place.

The ring gear for the starter is also heated and the installed with the contraction keeping it from slipping.
 
I’d lo love to see a video.
(Quite frankly I’m anazed today’s cylinder manufacturers are able to do this right, and that we don’t hear of valve seats falling out.)
 
Let'sgoflying! said:
I’d lo love to see a video.
(Quite frankly I’m anazed today’s cylinder manufacturers are able to do this right, and that we don’t hear of valve seats falling out.)
Click to expand...

There are lots of videos of head work on auto applications. The procedure is the same.


Valve seats do occasionally fall out. But for the most part they’re good. I would be more amazed at how manufacturers could do it with accuracy 60+ years ago, with today’s machines things have gotten easier.
 
Let'sgoflying! said:
(Quite frankly I’m anazed today’s cylinder manufacturers are able to do this right, and that we don’t hear of valve seats falling out.)
Click to expand...

It's a pretty simple interference fit calculation. That said, Jaguar got it somewhat off on the V12s, which were prone to run hot. The seats were looser than they should and would fall out under certain conditions. It never happened to me, but it did happen to others I knew and was a not-uncommon event.

The valve seats in aircraft engines are very hard. Once back at the engine factory we sent some cylinders out to a go-fast cylinder specialist to work his magic, which included putting in bigger valves. Logically, to put in bigger valves one must also put in bigger valve seats. He said these were the hardest seats he'd seen on any piston engine, period.

Oh, he did a good job. The engine made a lot of power.
 
Ted DuPuis said:
It's a pretty simple interference fit calculation. That said, Jaguar got it somewhat off on the V12s, which were prone to run hot. The seats were looser than they should and would fall out under certain conditions. It never happened to me, but it did happen to others I knew and was a not-uncommon event.
Click to expand...

There were a lot of failures on Jaguar V-12s that weren't an uncommon event. :D

In 1992 my brother bought an XJS, in spite of many recommendations not to. It blew a head gasket shortly thereafter, and to my amazement he didn't have the gasket on the other bank replaced while the failed one was repaired.

He discovered why that would have been more economical within another couple of thousand miles. :D
 
3393RP said:
There were a lot of failures on Jaguar V-12s that weren't an uncommon event. :D

In 1992 my brother bought an XJS, in spite of many recommendations not to. It blew a head gasket shortly thereafter, and to my amazement he didn't have the gasket on the other bank replaced while the failed one was repaired.

He discovered why that would have been more economical within another couple of thousand miles. :D
Click to expand...

I've owned half a dozen Jaguar V12s and worked on probably 50 more. For all of the complaining people do, I've found the things to be much more reliable than anyone who hasn't owned one would say. My first car was an '82 XJ-S V12, I put 30k miles on it freshman year of college. Not only did it get about 25 MPG on the highway (I converted it to a 5-speed manual with overdrive, which helped a lot) it never left me stranded. In those 30k miles the only two things I had go wrong related to the engine were the fuel pump quit and the distributor cap exploded (that's an odd failure mode pretty specific to the Jaguar V12).

Never had a dropped valve seat, I never even saw a blown head gasket - those were all on the 6-cylinder engines. In fact most of the problems we did were just basic tune-ups, replacing the 15-20 year old fuel hoses under hood, radiators, and air conditioning.

However, there were issues with quality out of the factory that I think made the ownership experience less reliable for new V12s than for the ones that made it to be 10+ years old.
 
Let'sgoflying! said:
I’d lo love to see a video.
(Quite frankly I’m anazed today’s cylinder manufacturers are able to do this right, and that we don’t hear of valve seats falling out.)
Click to expand...
It's possible that newer cylinder heads are built the same way as auto heads, with the valve seat cast in place.
 
RIght, right! I have seen all the auto YT valve seat insertion.
Maybe it's the same but I wanted to see someone working on a Lycoming or Continental, installing seats and guides. You know, the real thing. I can find how to remove my own appendix on YT, thought someone would have captured this. Just curious.
Thanks anyway.
 
Ted DuPuis said:
I've owned half a dozen Jaguar V12s and worked on probably 50 more. For all of the complaining people do, I've found the things to be much more reliable than anyone who hasn't owned one would say. My first car was an '82 XJ-S V12, I put 30k miles on it freshman year of college. Not only did it get about 25 MPG on the highway (I converted it to a 5-speed manual with overdrive, which helped a lot) it never left me stranded. In those 30k miles the only two things I had go wrong related to the engine were the fuel pump quit and the distributor cap exploded (that's an odd failure mode pretty specific to the Jaguar V12).

Never had a dropped valve seat, I never even saw a blown head gasket - those were all on the 6-cylinder engines. In fact most of the problems we did were just basic tune-ups, replacing the 15-20 year old fuel hoses under hood, radiators, and air conditioning.

However, there were issues with quality out of the factory that I think made the ownership experience less reliable for new V12s than for the ones that made it to be 10+ years old.
Click to expand...

I was just funnin' you. :D
 
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