interesting op engines

[derekliston]

On 29/6/2023 at 2:41 PM, facthunter said:

The best civilian life (Derated from wartime ) was 650 hours but many Countries never allowed it on their civil register.  Nev.

BOAC used to operate Argonauts which I think were basically DC4s with Merlin engines. Lancastrians and Yorks were also Merlin engined. All of them were on the British civil register I think? Do you have any idea of what sort of engine life they had? (I haven’t)

[facthunter]

650 is the highest reliable figure I've come across The problem is the single skew gear that drove both Magnetos. . That's the reason for the lack of approval in many Countries. Another might have been the overheating problem on the ground and the lack of rollers on the cam followers, that most other V 12's had and which sometimes resulted in scuffing of the surfaces on start up.  The TBO is only 1/3rd of the Original DC4 P&W R-2000 engine and individual "POTS" are easier to service the Banks of 6 cylinders.  Nev

[derekliston]

9 minutes ago, facthunter said:

650 is the highest reliable figure I've come across The problem is the single skew gear that drove both Magnetos. . That's the reason for the lack of approval in many Countries. Another might have been the overheating problem on the ground and the lack of rollers on the cam followers, that most other V 12's had and which sometimes resulted in scuffing of the surfaces on start up.  The TBO is only 1/3rd of the Original DC4 P&W R-2000 engine and individual "POTS" are easier to service the Banks of 6 cylinders.  Nev

Sorry this thread is drifting badly, but interesting! I always disliked the Lycoming engine model which had the dual magneto for that same reason, lose the drive and you lost both! Years before I worked on aircraft I had an uncle who told me that if a plane came in with a glycol leak, they sent the pilot back up to wreck the engine because it was easier to change the engine than fix the leak! Truth? No idea but sounds possible!

[facthunter]

Yes I don't think it was much of a magneto but how  many failures it had I don't know, Skew gears are more prone to failure as their lubrication needs are more critical. A lot of people think the Merlin is designed by God.. I have seen them leaking coolant but that would be neglect and the one I know of only ran water. .  and it was used for banner and target towing.  Nev

[BrendAn]

12 minutes ago, derekliston said:

Sorry this thread is drifting badly, but interesting! I always disliked the Lycoming engine model which had the dual magneto for that same reason, lose the drive and you lost both! Years before I worked on aircraft I had an uncle who told me that if a plane came in with a glycol leak, they sent the pilot back up to wreck the engine because it was easier to change the engine than fix the leak! Truth? No idea but sounds possible!

its not drifting badly at all. its interesting reading.

[Litespeed]

On 29/06/2023 at 2:36 PM, BrendAn said:

i am pretty sure these companies do research. i would say the small version they say is going to market this year is aimed at drones. looks about the right size and seems to be a lot of manufacturers after the military contracts.

They definitely will be a big hit in the drone market esp for long range quadcopters as a generator.

Just like Jabiru are used in lots of military drones now. 

As a generator/ battery extender it has a future.

[Bruce Tuncks]

The easiest shape to try and seal is a round cylinder. You only have to consider an old smoky motor to see that cylindrical is hard enough. I'm impressed that the rotary engines work at all, but they sure are battling hard with combustion chamber sealing.

[Area-51]

34 minutes ago, Bruce Tuncks said:

The easiest shape to try and seal is a round cylinder. You only have to consider an old smoky motor to see that cylindrical is hard enough. I'm impressed that the rotary engines work at all, but they sure are battling hard with combustion chamber sealing.

Bag of cement used properly will seal any type of combustion chamber, once; shape is not an issue 🧐

[facthunter]

Just don't try this at home. Suggesting you fly it and wreck it to get  a water leak fixed, How do you arrange to get It safely back to the aerodrome?  Fact is Poppet valves AND Cylinders ARE the best at sealing. Quite a few aero cylinders were "choked" (smaller dia at the top) to be truer when hot. Flowed valved ports are also super efficient and WHO does valve grinds any more?.  Nev