Merlin XXX HP?

[RCAFson]

Most sources state the Merlin XXX as having 1300hp, yet even the Merlin III was pushing over 1400 hp when modded for 16lb boost. I wonder if anyone has info regarding max boost for the Merlin XXX and resulting HP?

 

[Shortround6]

Most sources state the Merlin XXX as having 1300hp, yet even the Merlin III was pushing over 1400 hp when modded for 16lb boost. I wonder if anyone has info regarding max boost for the Merlin XXX and resulting HP?

One source says 1300hp at 12.5lbs boost for take off.

The engine used a 9.75in impeller instead of the "normal" 10.25in impeller. It used an 8.58 supercharger gear ratio the same as the Merlin III, which used a 10.5in impeller.

The Merlin 32, which was supposed to be similar the Merlin 30 only with two piece blocks, was rated at 1620hp at 18lbs of boost. It's rated altitude may have been 1500ft.

The Merlin 30 was used in the Fulmar MK I and the Barracuda MK I, with the MK II Barracudas shifting to the Merlin 32. With only 660 of the Merlin 30s built perhaps they never got around to "approving" a higher boost?

I believe the 16lb boost rating for the Merlin III was for the Sea Hurricane?

 

[RCAFson]

One source says 1300hp at 12.5lbs boost for take off.

The engine used a 9.75in impeller instead of the "normal" 10.25in impeller. It used an 8.58 supercharger gear ratio the same as the Merlin III, which used a 10.5in impeller.

The Merlin 32, which was supposed to be similar the Merlin 30 only with two piece blocks, was rated at 1620hp at 18lbs of boost. It's rated altitude may have been 1500ft.

The Merlin 30 was used in the Fulmar MK I and the Barracuda MK I, with the MK II Barracudas shifting to the Merlin 32. With only 660 of the Merlin 30s built perhaps they never got around to "approving" a higher boost?

I believe the 16lb boost rating for the Merlin III was for the Sea Hurricane?

According to the data from this board, it seems that the Merlin 30 and 32 are almost identical except for a two piece cylinder block in the Merlin 32, and the fact that the Merlin 32 is cleared for 18lb boost.

Merlin 30 = 1360hp at 6000ft @ 12lb boost
Merlin 32 = 1640hp at 2000ft @ 18lb boost

This has implications for the Fulmar II as it would seem that if the Merlin 30 could be modded for more boost, it could develop significantly more power, equal to about 45hp per extra lb of boost. A Merlin 30 with 14lb boost would probably develop 1450hp and at 16lb, about 1540hp, and a Fulmar II would probably be able to top 290mph with that kind of power and climb at over 2000fpm. i suspect that Fulmar performance has been greatly understated as most sources seem to quote 1300hp for the Merlin 30 equalling 270mph for the Fulmar II.

Yes, according to Wings of the Navy, (via Wikipedia) the Sea Hurricane IC was rated for 16lb boost during Pedestal and I would suspect that the IB was probably rated for at least 14lb boost during the same time frame. Also according to Wikipedia the Sea Hurricane IIC's Merlin XX was rated at 1460hp at 6250ft and this seems to indicate 14lb boost.

 

[Colin1]

I'm showing

Merlin 30 1300hp @ 3000rpm @ SL as fitted to the Fairey Barracuda I
Merlin 30 1260hp @ 3000rpm @ 8750ft as fitted to the Fairey Fulmar II

Type: Navy engine, single-stage, single-speed, Koffman starter


Merlin 32 1645hp @ 3000rpm @ 2500ft as fitted to the Fairey Barracuda I and Seafire II

Type: Single-stage, single-speed, Koffman starter


Threw me for a wee while, strictly speaking, the use of Roman numerals stopped at the Merlin XX

 

[RCAFson]

I got the Merlin 30 and 32 data from here:
http://www.ww2aircraft.net/forum/en...y-war-lets-get-straight-15743.html#post424013

 

[krieghund]

These are from "The Merlin in Perspective" Roll-Royce Heritage Trust - 1983