Can we make a slightly smaller Fulmar as an improved carrier fighter?

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Well, let's (optimistically?) say that by not putting Griffon on hold and canceling those other projects, Griffon could be introduced into service 18-24 months earlier than historically.

However, arguably putting Griffon on hold was a mistake, as that was clearly the lowest risk project for delivering more power than the Merlin.
In one sense you are correct but I would suggest that the Griffon would parallel Merlin, using the same boost limits as the Merlin at about the same times.

Also note that any estimates of 1939/early 1940 perfromance would be with a Pre-Hooker supercharger and not the Merlin XX/45 design.
 
A developed 'R' engine (ie Griffon I) was a possibility, but they stopped development sometime in the mid- to late-1930s in order to work on a clean-sheet design which became the Griffon II.

The Rolls-Royce 'R' racing engine.


In the 1929 Snyder Cup race the 'R' ran at 1800 BHP for 40 min. They were using a special racing fuel blend that (If my info is correct) had an approximate PN of 95/125.

In 1934 Rolls-Royce was running 100 hr at 1500 BHP endurance tests on a modified 'R' engine as part of the development for the Griffon I. The Griffon I development was discontinued after about 1937 or 38(?) and work started on the clean-sheet Griffon II.

They ended up using the knowledge gained with the 'R' to aid in the development of the later-Kestrel and Peregrin/Merlin/Griffon series.
 
To an extent the prime virtue of the Hurricane vs. the Spitfire was that they could build them faster and cheaper. But for a carrier aircraft in particular, it makes even less sense to focus on cheapness than for a land based aircraft as the carrier is a very expensive asset and space is at a premium. So you want your planes to be the best you can get. Or most capability per used space in the hangar, or however you want to measure it. Also significantly easier to sink a carrier than an airfield, thus putting even more importance in being able to fend of attacks.

Of course, if strapping a hook on a Hurricane makes for a quick stopgap interceptor while working on a proper Seafire, by all means, but priority should absolutely be a Spitfire based interceptor (if one has to choose between Sea Hurricane and Spitfire).
 
I still say a fighter long endurance (with decent speed) is still better than an interceptor for carrier ops.
 
Fully agreed. In my fantasy scenario, Merlin would still be priority #1, as it historically was, for good reasons. But IMHO #2 should have been Griffon, then as a follow-up to Griffon as priority #3 look into something slightly more exotic (much as the V-12 is a really nice layout, for something substantially bigger than Griffon the per-cylinder volume starts to get awfully big in a V-12 configuration). But keep that as boring and safe as possible too. A poppet valve H-24 would reduce risks with bearings/crankshafts like X-layout Vulture suffered from, and also not go down the sleeve valve rabbit hole like Crecy or Eagle. Then all the two-stroke, sleeve valve, X layout, air cooled inlines, etc. stuff can be done as science projects with relatively low funding.
 
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How bad would've been the 'British DB 603', displacement-wise?
 
Kind of depends on what the British will accept for fpm of piston speed and what they want for engine life.
There was probably no law in the British legal system that deals with piston speeds
DB603 with 2550rpm?
DB 603 used pistons 10mm bigger than the Griffon and 8mm bigger than DB 605.
British have better alloys?

British indeed have had better materials. I'm okay with 2700 rpm on the British 603.
 
Drop tanks make wonders.

I don't think external tanks are enough for a plane like a Spitfire ... otherwise they would have been escorting strikes to Berlin. Or at least Hamburg. Same applies to Bf 109 or MC 202. Or most of the Soviet fighters.
 
I still say a fighter long endurance (with decent speed) is still better than an interceptor for carrier ops.
They tested an F4F-3 with underwing "slipper" tanks, not adopted.

They put a pair 58 US gal tanks under F4F-4s or FM-1s but apparently not until 1943 or later?

Of course a pair of 58 gal tanks under an F4F may kill the notion of decent speed.
 

yeah these show up quite a bit in the later war, on FM-2 as well I think. I think they are good - if you need to scramble to altitude they can be dropped. If they are flying around on a long CAP mission and detect enemy strike incoming they can immediately drop the external tanks (and probably still have pretty full internal tanks). They can also use the fuel on the way to the target on an escort mission.

The key thing is that the Wildcat still has decent range without the external tanks. So if they do have to drop them on a long flight, they can still make it back to base.


This is a wonderful photo by the way.
 
I don't think external tanks are enough for a plane like a Spitfire ... otherwise they would have been escorting strikes to Berlin. Or at least Hamburg. Same applies to Bf 109 or MC 202. Or most of the Soviet fighters.
How much fuel was carried by a Fulmar, internal + external?
 
How much fuel was carried by a Fulmar, internal + external?

155 (I think Imperial) gallons internal.

They had some kind of 60 gal tank for them, which was carried on the centerline. Don't know if they ever developed / plumbed for (external) wing tanks.
 
155 (I think Imperial) gallons internal.

They had some kind of 60 gal tank for them, which was carried on the centerline. Don't know if they ever developed / plumbed for (external) wing tanks.

Makes for 215 imp gals.
A Spitfire with a 90 gal drop tank carries 174 imp gals total. Tuck in another 20 gals and there is no advantage for Fulmar since it was heavier and draggier, so it will use more fuel both in combat and away.
Hurricane with 2x45 gals in DTs = ~185 imp gals? The Mk.II was rated for both 2x45 and 2x90 gals.
 
While RR has been puttering around with modified R engine(s). The "official" Griffon I development didn't start until '38, 1st run at end of Nov, '39 and tossed in recycle bin 4/Dec/'39 for the clean sheet Griffon II.

Z z42
If you're wanting mass produced Griffon I, you're getting engine that doesn't fit in Spitfire, and is 'only' good for 1,750hp max. as like Merlin I, it is designed around the limits of 87 octane fuel.

Griffon II, in addition to much better packaging, and is running a much more efficient supercharger.

Also, isn't the Vulture supercharger the starting point for the 1st stage of the two stage Merlin?

Butterfly effect of pulling some things in/cancelling others has unintended consequences.
 
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