R-R Merlin power

[MiloMorai]

Spitfire I

Maximum power the engine is designed to safely and reliability produce is ~400hp

This is the power produced at max continuous for 4 1/2 lb boost @ 2600rpm.

Thoughts and comments.

[Charge]

Thoughts:

What is the definition of "safely and reliably"? Some certain amount of hours?

Is such low amount of HP the initial design aim of engine family from which Merlin emerged, i.e. not exactly what Merlin was capable of?

Where did you come by such figure?

-C+

[Klam]

There is some useful stat's and info' pertaining to Merlin engine variants and the Spitfire

http://www.historyofwar.org/articles/weapons_spitfire_mkI.html

[MiloMorai]

The person who made the statement said: "You are talking about running the engine at 3 times its original design maximum capacity."

[Jabberwock]

Hmmmm, odd numbers. I'd estimate a Merlin III at + 4.5 lbs boost/2,600 rpm would be producing about 700-850 hp depending on altitude, not 400 hp. Merlin II maybe a touch less.

See: http://www.spitfireperformance.com/merlin3curve.jpg

Also, much depends on the time period. For example, when the Merlin III was cleared to operate at +12.5 lbs in 1940, the max continuous cruise was set at +7 lbs and 2650 rpm, which would give more than 1000 hp, depending on the altitude. 

See the first post here: http://forum.1cpublishing.eu/showthread.php?t=18865

Note the indicated values for the power curve at 13,500 ft, which gives 831 hp at 4.3 lbs boost.

[MiloMorai]

Thanks Jabberwock, that is what I am looking for.

[NZTyphoon]

Hmmmm, odd numbers. I'd estimate a Merlin III at + 4.5 lbs boost/2,600 rpm would be producing about 700-850 hp depending on altitude, not 400 hp. Merlin II maybe a touch less.

See: http://www.spitfireperformance.com/merlin3curve.jpg

Also, much depends on the time period. For example, when the Merlin III was cleared to operate at +12.5 lbs in 1940, the max continuous cruise was set at +7 lbs and 2650 rpm, which would give more than 1000 hp, depending on the altitude. 

See the first post here: http://forum.1cpublishing.eu/showthread.php?t=18865

Note the indicated values for the power curve at 13,500 ft, which gives 831 hp at 4.3 lbs boost.

Just to clarify; the Merlin II and IIIs were cleared for +12lbs boost in November 1939, while the Merlin XII in Spifire IIs was cleared for +12.5lbs at about the same time - check out http://www.spitfireperformance.com/spit1-12lbs.jpg  http://www.wwiiaircraftperformance.org/ap1590b.jpg the Merlin II's lowest power rating given in t=18865 = 684 hp at +2.2lbs