Rolls Royce R and Merlin,

[Davidh subs]

Hello

I am new to this forum and only really have one question. But I would appreciate any response.

This is with regards to the Rolls Royce R and the Merlin.

The Rolls Royce R engine of Schneider trophy fame developed in 1931-32 up to 2,800 hp! 2,800! I realize that this was exceptional,

Why was the performance levels of this engine not transferred directly across to the Merlin? How different could the Battle of Britain been if the early Spitfires were using an engine of over 2,000 hp rather than the 1030 hp of the early Merlin’s.

It almost seems that Engine development went backwards for a couple of years. Here was an engine , the R that was producing the levels of power that only seems once again to become available around 1944-45. Why is this?

Was it because the R was unreliable and the technology had not matured?

Thankyou

Regards

David H

 

[rb1957]

yes, I think the engine was highly optimised for the racing environment, much like F1 in cars, and not at all suitable for mass production, long duration, long term maintenance, long term serviceability.

another day in paradise, or is paradise one day closer ?

 

[WKTaylor]

FYI...

Rolls-Royce Piston Aero Engines: A Designer Remembers by A. A. Rubbra

https://www.bonanza.com/listings/Ro...MIqYbYivLt6gIVzR-tBh2UOwD9EAQYAyABEgIBgfD_BwE

Allied Aircraft Piston Engines of World War II, 2nd Revised edition, SAE R-154

Historical Series Book List - December 2018

https://www.rolls-royce.com/~/media...s/about/heritage-trust-book-list-dec-2018.pdf

Regards, Wil Taylor
o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]

 

[berkshire]

More Information,
The Rolls Royce R engine was developed from the Rolls Royce Buzzard which in turn was a scaled up version of the RR Kestrel engine. The R engine had a very short production run, only 19 engines were produced.
If you ever get the opportunity a visit to the Rolls Royce Heritage trust museum in Derby UK is a very rewarding visit, there on display they have engines ranging from the Rolls Royce Eagle and Kestrel to the RB211.
I really think this post should really be in the Engineering History forum
B.E.

You are judged not by what you know, but by what you can do.

 

[Lou Scannon]

A couple of key differences...
[ol 1]
[li]The R was a racing engine, which has different and less onerous longevity and reliability requirements compared with a military engine[/li]
[li]The Merlin displaces around 27 litres, whereas the R was around 10 litres larger, if I'm not mistaken[/li]
[/ol]
Also, if I'm not mistaken, the R displacement was re-used in the Griffon.
The Griffon was the ultimate liquid cooled reciprocating aero engine that was produced in any numbers, but its development was cut short by the advent of the gas turbine.

The was a special high performance version of the Merlin that was tested around 1950, I believe, that reached a BMEP of 360psi. That's about 24 bar. I doubt that's ever been topped in a factory developed recip aero engine but I would love to learn otherwise.

A key advantage that the Merlin conferred on the aircraft it was used in, compared with their adversaries, was its smaller displacement and mass for about the same power.
Rolls Royce took advantage of combustion know-how and especially access to better base fuels and antiknock additives compared with their German counterparts, to pull this off.

The large frontal area of the Daimler Benz and Junkers V-12 engines caused the aircraft designers to mount these engines inverted on fighter aircraft, to give the pilots a chance of seeing over the engine.

One of the last Merlin serial applications was the infamous Canadair Northstar, AKA DC-4M, AKA Argonaut. Interesting is that take-off power in this rating was well over 1hp per cubic inch. Considering commercial aviation recip engines I think the only other type to approach this was the Wright Turbocompound.

All the above going off memory, so I'm willing to be corrected.

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[Davidh subs]

Thank you people,

I would love to visit the Rolls Royce heritage trust museum in Derby but its along way from Sydney Australia.

I had my suspicions about the R not being suitable to develop into a full military engine, I just wanted to see it confirmed, I'm guessing that the high HP readings and these levels of performance where only for minutes at a time and wouldn't have been able to be maintained for any length of time certainly not on long missions into Germany and back.

Still, amazing technology.

If Hollywood can make a film called "Ford vs Ferrari' I would love to see a film called "Supermarine vs Macchi"

thankyou,

David Hughes.

 

[Sparweb]

You might find Stanley Hooker's life story interesting: Not Much of an Engineer

http://www.sparweb.ca

 

[rb1957]

also Neville Shute's autobiography. He worked for RR on the merlin, improved the supercharger.

Also R engine is not related to the later Griffon offshoot of the Merlin … at least according to wiki.
There was a "Griffon" R engine development.

another day in paradise, or is paradise one day closer ?

 

[Lou Scannon]

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz