Let’s talk about a serious procedure. Calling big bore Turbo engine operators !

[Fly Boomer]

10 hours ago, aviatoreb said:

My rocket TSI520NB engine had about 1400 hrs on it when I was forced to remove 6 perfectly good ECI Titan cylinders due to an AD and put 6 new ones which I got from Victor because I had them do the multi-angle valve job described here.  Now I am at about 1950 hrs.

Is that 1950 since cylinders or SMOH?

[A64Pilot]

13 hours ago, goodyFAB said:

 

Who does cylinder work like that? 
 

maybe drop shipping a set of cylinders makes sense !

Carlos Gann does, as well as port and polish the ports, on his “performance” overhauls but every engine component gets balanced to less than 1 gram 1/28th of an ounce.

His engines are known for smooth running and his performance engines make quite a bit more power than average

I think but don't know that he was an engine builder for NASCAR before aircraft and assume that’s where a lot of what he does comes from.

I don’t have any idea if he would rework cylinders or only does them for his overhauls.

I guess you could call and ask

https://www.gannaviation.com/engine-overhauls

Edited August 4, 2023 by A64Pilot

[1980Mooney]

20 hours ago, goodyFAB said:

The procedure would be to top overhaul… 

theres a lot of information out there that points to catastrophic failure after cylinder replacement. 

You just made the case why you need to pick your shop based upon their expertise, experience and reputation with big bore Continentals.  It is directly related to the skill and care of the installer.  Yes, the quality of the parts can be an issue but a good installer knows what to look for (see comments in last Aviation Consumer article).  Through bolts need to be torqued from both ends.  That may require quite a bit of disassembly of accessories to gain access.  The horror stories that you hear from Mike Busch (you must have been watching his YouTube "Cylinder Work: Be Afraid - Risky Business") are generally because a mechanic reused parts or cut corners and did not properly torque everything.- esp. through bolts because the couldn't or didn't want to take the time to get proper access.  That is one reason Busch advocates removing the engine and putting on a stand to do cylinder replacement. 

Over more than 2 decades I have had a couple cylinders replaced on a big bore Continental with the engine in place.  There has been absolutely not problem what so ever.  Everything in aviation is time and money.  There is no reason why the Top O/H can't be done with the engine in plane on the plane.  You can be cautious and follow Mike Busch's recommendation to pull the engine but if you go that far, especially with a Rocket, you are more than halfway in cost to an complete Overhaul.

Here are some sane articles from Aviation Consumer on Top O/H.  Notice in the picture that they have a Mooney with 6 cylinder Continental getting a Top.  Sadly the link to "Top O/H Checklist" no longer works - perhaps cost cutting/atrophy setting in with the new owner of Aviation Consumer.... 

https://www.aviationconsumer.com/maintenance/top-overhaul-survivor-guide/

https://www.aviationconsumer.com/maintenance/you-gotta-top-it/

https://www.aviationconsumer.com/maintenance/good-jugs-bad-jugs/

 

Edited August 4, 2023 by 1980Mooney

[A64Pilot]

I believe most of the issues that come from cylinder replacement stem from having one cylinder replaced, not the whole lot.

The reason I believe this as has been stated both sides should be torqued, although I’ve never found the other side loose as of course unless the stud is bound some how, torque is distributed to the other end.

It’s a lot of extra work to remove the baffling on the side your not working on just to hear the torque wrench click with no movement, so I guess some don’t bother pulling the baffling on both sides, but again I’m going to guess that every now and again a stud does have interference in the fit and only torquing one side has the thing loosen up when run.

Plus the adapters required to torque the nuts are a PIA and require some finesse, you have to pay attention to ensure your torquing correctly.

I guess as the owner you need to have a talk with the mechanic and ensure both sides are torqued, and the prop not touched when the cylinders are off.

If I were an engine shop I would cut off the base of junk cylinders and when the cylinders were in for overhaul I’d install those plates and torque them, just for insurance.

In truth spun bearings from any cause are exceedingly rare, and cylinders are replaced it seems about as often as spark plugs so induced failures are very uncommon.

Edited August 5, 2023 by A64Pilot