Griffon powered Hurricane....

[Readie]

You have 3 questions to deal with. Yes the Griffon was delayed while they concentrated on Merlins but that doesn't mean that the Griffon was completely sorted out, finished testing and ready to go as soon as factory space could be found for it in 1941, early 42. Griffon (single stage) was much heavier than the Allison. It will fit but it is going to be about as much of an engineering job as putting in the two stage Merlin.
It seems to have taken the US about 18 months at BEST to get a new engine plant into production, at worst took a while a longer. Converting from one model to another does go much faster but can still take months. Packard started work on the two stage Merlin in Feb 1942, ran the first test engine in May but delivered the fifth production 2 stage engine in Dec of 1942. Making griffons might be 1/2 way in Between? Yes it is a -12 but there are few common parts.

We didn't have (nor would ever have) the manufacturing base that the Americans have. The Griffon was intended to replace the Merlin but, the Merlin with the new superchargers did everything that was asked of it.
So, to answer the question, I reckon that RR would have fitted the 37L Griffon to all RAF planes given the chance but, that chance wasn't there due to circumstances at the time.
We used the best we had and made the most of it in our own British way.
My own view is that Napier had stolen the march in engine development over RR and the engineers also knew that the jet age was just around the corner.
The Merlin carried on and much as it grieves me to admit it.....no I can't say that,I 'll end up in the Tower of London for high treason.

Cheers
John

 

[wuzak]

The Griffon was not designed to replace the Merlin. It was a response to a FAA request for a larger version of the Merlin. It just so happened that a fellow from the MAP asked "can we fit a Griffon to the Spitfire", and Joe Smith said "well, with some help from Rolls-Royce, yes we can!"

 

[Shortround6]

Don't worry..... you are safe. The Napier was a bit of stretch that went too far. Nice concept and great potential but the cost wasn't worth it. Just look at it's post war success

Now Bristol on the other hand..........

 

[Readie]

Don't worry..... you are safe. The Napier was a bit of stretch that went too far. Nice concept and great potential but the cost wasn't worth it. Just look at it's post war success

Now Bristol on the other hand..........

Pity about Napier, I know what you mean. The sleeve valves have their supporters and power there in spades with the new superchargers.

The Centaurus was one of the ultimate areoengines.

The irony, for me at least, is that the radial outpowered the liquid cooled inline.

Cheers
John

 

[Readie]

The Griffon was not designed to replace the Merlin. QUOTE]

You sure?

Although the Griffon was designed for naval aircraft, on 8 November 1939 N E Rowe of the Air Ministry suggested fitting the Griffon in a Spitfire. Three weeks later permission was given to Supermarine to explore the possibilities of adapting the Griffon to the Spitfire; in response Supermarine issued 'Specification 466' on 4 December. This decision led to a change in the disposition of the engine accessories to reduce the frontal area of the engine as much as possible As a result the frontal area of the bare Griffon engine was 7.9 sq ft compared with 7.5 sq ft of the Merlin.This redesigned engine first ran on 26 June 1940 and went into production as the Griffon II.

In early-1940, on the orders of Lord Beaverbrook, Minister of Aircraft Production, work on the new engine had been halted temporarily to concentrate on the smaller 27 L Merlin which had already surpassed the output achieved with the early Griffon.

Had things gone better for us in the early years of WW2 I'm sure that the resources would have been put into the Griffon to develop it. It had a lot of offer 10L, better lubrication all in a compact package.

Cheers
John

 

[Siegfried]

BTW, the Hurricane originally had a retractable tail wheel but this was deleted in production aircraft.

I believe the tail wheel added stabillity to the airframe and made it much easier to spin recover. One reason for not having it retractable.

 

[wuzak]

The Griffon was not designed to replace the Merlin.

You sure?

Although the Griffon was designed for naval aircraft, on 8 November 1939 N E Rowe of the Air Ministry suggested fitting the Griffon in a Spitfire. Three weeks later permission was given to Supermarine to explore the possibilities of adapting the Griffon to the Spitfire; in response Supermarine issued 'Specification 466' on 4 December. This decision led to a change in the disposition of the engine accessories to reduce the frontal area of the engine as much as possible As a result the frontal area of the bare Griffon engine was 7.9 sq ft compared with 7.5 sq ft of the Merlin.This redesigned engine first ran on 26 June 1940 and went into production as the Griffon II.

In early-1940, on the orders of Lord Beaverbrook, Minister of Aircraft Production, work on the new engine had been halted temporarily to concentrate on the smaller 27 L Merlin which had already surpassed the output achieved with the early Griffon.

Had things gone better for us in the early years of WW2 I'm sure that the resources would have been put into the Griffon to develop it. It had a lot of offer 10L, better lubrication all in a compact package.

Cheers
John

Yes, I'm sure.

The Griffon wasn't intended to replace the Merlin, though it did in some airframes, most notably the Spitfire. Most Merlin applications were unaffected, however.

 

[Readie]

Yes, I'm sure.

The Griffon wasn't intended to replace the Merlin, though it did in some airframes, most notably the Spitfire. Most Merlin applications were unaffected, however.

Ok, that's interesting. I'll have a read through my stuff. The age old question is was the Griffon a better engine than the Merlin?
What is your view?
Cheers
John

 

[Shortround6]

Better How?

More power per pound of weight?

Much more important to an aircraft designer/customer than power per liter. nobody was giving out medals/trophies for fastest plane with XXX sized engine either in war or in airline service.

More time between overhauls?

Better fuel economy?

See power for weight. less fuel means bigger war load or more passengers/freight over a given distance.

Less likely to break in flight?

Probably should be first on the list

 

[Readie]

Better How?

More power per pound of weight?

Much more important to an aircraft designer/customer than power per liter. nobody was giving out medals/trophies for fastest plane with XXX sized engine either in war or in airline service.

More time between overhauls?

Better fuel economy?

See power for weight. less fuel means bigger war load or more passengers/freight over a given distance.

Less likely to break in flight?

Probably should be first on the list

Hello SR6,

I meant 'better' as a very general overall description. I am interested in Wuzak's view.

Reliability is not usually an issue with RR.

The first thing that springs to mind is that the propellor technology took a little while to catch up with the Merlin's power and if that was adequate then resources spent on superior firepower etc would give a better advantage than masses more power.

Cheers
John

 

[wuzak]

I believe that the Griffon was a superior design than the Merlin because it used lesson learned in the Merlin program, some of which were then applied back to the Merlin - like end to end lubrication.

Most two stage Merlins were around the 1hp/lb mark, though they ended up going to 2200hp, or 1.3hp/lb. Griffons started life at around 1hp per pound also. After teh war they were able to go to 2500hp, which is 1.2-1.25hp/lb. So in terms of hp/lb the two are not disimmilar. I dare say that the Griffon at 2000hp uses less fuel than the Merlin at 2000hp, though the Merlin probably uses less in a cruise (that is, with less power also).

But the Merlin had a lot more development resources spent on it during the war.

 

[stug3]

How bout a Griffon 65 powered Mustang? I couldnt find much info on this, which I guess shouldnt be surprising since it never made it off the drawing board. Looks like it would have had a 20mm in the nose 2 .50s in each wing.

 

[wuzak]

Apparently there was some discussion withing the MAP, Rolls-Royce and NAA about using the Griffon in the Mustang at the time they were investigating the Merlin installation.

Proposals were put forward for Mustangs powered by Merlin XXs, Merlin 61s and Griffon 61s.

I don't think the Merlin XX version was built, Rolls-Royce built the Mustang X with Merlin 61s and NAA followed on a similar path a short time later. NAA said that there would be too much modification required to fit the Griffon, and that went nowhere.

Until Rolls-Royce proposed and started building (the mockup of) that mid engined beast.

 

[glennasher]

It begs another question, how would Griffons work in Lancs?

 

[Greyman]

It begs another question, how would Griffons work in Lancs?

hmm, Avro Shackleton might be worth looking at?

 

[wuzak]

Avro Shackleton

General characteristics
Crew: 10
Length: 87 ft 4 in (26.61 m)
Wingspan: 120 ft (36.58 m)
Height: 17 ft 6 in (5.33 m)
Wing area: 1,421 ft² (132 m²)
Airfoil: modified NACA 23018 at root, NACA 23012 at wingtip [15]
Empty weight: 51,400 lb (23,300 kg)
Max. takeoff weight: 86,000 lb (39,000 kg
Fuel capacity: 4,258 imperial gallons (19,360 L)
Powerplant: 4 × Rolls-Royce Griffon 57 liquid-cooled V12 engine, 1,960 hp (1,460 kW) each
Propellers: contra-rotating propeller, 2 per engine
Propeller diameter: 13 ft (4 m)
Performance
Maximum speed: 260 kn (300 mph, 480 km/h)
Range: 1,950 nmi (2,250 mi, 3,620 km)
Endurance: 14.6 hours
Service ceiling: 20,200 ft (6,200 m)
Max. wing loading: 61 lb/ft² (300 kg/m²)
Minimum power/mass: 91 hp/lb (150 W/kg)
Armament
Guns: 2 × 20 mm Hispano Mark V cannon in the nose
Bombs: 10,000 lb (4,536 kg) of bombs, torpedoes, mines, or conventional or nuclear depth charges, such as the Mk 101 Lulu


Avro Lancaster
General characteristics
Crew: 7: pilot, flight engineer, navigator, bomb aimer/nose gunner, wireless operator, mid-upper and rear gunners
Length: 69 ft 4 in (21.11 m)
Wingspan: 102 ft 0 in (31.09 m)
Height: 20 ft 6 in (6.25 m)
Wing area: 1,297 sq ft (120.5 m²)
Empty weight: 36,457 lb (16,571 kg)
Loaded weight: 68,000 lb (30,909 kg) [42]
Max. takeoff weight: 72,000 lb (32,727 kg) with 22,000 (10,000 kg) bomb
Powerplant: 4 × Rolls-Royce Merlin XX liquid-cooled V12 engines, 1,280 hp (954 kW) each
Performance
Maximum speed: 282 mph at 63,000 lb (28,576 kg) and 13,000 ft ( 3,962 m) altitude [37] (246 knots, 455.6 km/h)
Cruise speed: 200 mph (174 knots, 322 km/h)
Range: 2,530 mi (2,200 nmi, 4,073 km)
Service ceiling: 21,400 ft at 63,000 lb (32,659 kg)[37] (6523 m)
Rate of climb: 720 ft/min at 63,000 lb (28,576 kg) and 9200ft (2,804 m) altitude[37] (3.66 m/s)
Armament
Guns: 8× 0.303 in (7.7 mm) Browning machine guns in nose, dorsal and tail turrets, with variations[42]
Bombs: Maximum normal bomb load of 14,000 lb (6,300 kg) or 22,000 lb (10,000 kg) Grand Slam with modifications to bomb bay.[42]


The Shackleton is a bigger aircraft, and is quite a bit heavier. But it is (marginally) faster.

I would think that swapping the Merlins for Griffons could be done relatively easily. The problem then would be that the range is reduced because of the higher fuel consumption of the Grifons. That would need some added tankage. I suggested that wing tip tanks could be used.

The next thing is whether the extra weight of the engines and fuel reduces the bomb load to be carried.

A Griffon VI is about 400lb heavier than a Merlin 20 series. Call it 1600lb all up. If that has to come from the bomb load, is it worth it?

 

[tomo pauk]

A Griffon VI is about 400lb heavier than a Merlin 20 series. Call it 1600lb all up. If that has to come from the bomb load, is it worth it?

Do what was done on the Specials - delete front and dorsal turets?

 

[nuuumannn]

The Shackleton was based on the Lincoln and used Tudor assemblies and was fitted with the Lincoln's wing. There was a consideration by Avro to fit the Lanc with the Griffon, but by late 1943 the firm had been working on the Lancaster B.IV, which promised better performance than the earlier Lanc with little disruption to production lines, so due to the differences between the earlier Lancs and the new one, it was called the Lincoln. So, the reason the Lanc wasn't fitted with the Griffon was as much to do with what was already in place and the speed by which the new design could get into service.

As for the Mustang X modififed by Rolls-Royce, these were powered by Merlin 65s, basically 63s with a greater rotor diameter and were used almost exclusively in the Mustang. The 63 didn't have the cabin supercharger as fitted to the '61 that was going into the HF.VII etc.

Stug, the best source of info on the Rolls-Royce Mustang FTB comes from the book Rools-Royce and the Mustang by David Birch and published by the Rolls-Royce Heritage Trust. Wiki has a little detail taken from that book

Rolls-Royce Mustang Mk.X - Wikipedia, the free encyclopedia

I'll throw some detail down at a later time; I'm a bit busy right now.

 

[nuuumannn]

Just a wee addition to this; the Griffon was considered for the Hurricane at one stage and an example was modified to take one in early 1941, but the Air Staff thought that it was not worth the effort and cancelled it.

 

[OldSkeptic]

Just a wee addition to this; the Griffon was considered for the Hurricane at one stage and an example was modified to take one in early 1941, but the Air Staff thought that it was not worth the effort and cancelled it.

And quite right too. Took Camm and his team far too long a time to twig to thin wings (ie the Tempest) for low drag and a high mach limit.
He was a great, actually brilliant designer, but he could be very stubborn and, as like in this case, would sometimes stick to wrong ideas for far too long.

You read the various accounts about him and you get the feeling (at least I do) that sometimes someone should have just given him a big boot up the a@@ and say "do it that way Sydney".
There was no reason why the Typhoon couldn't have been a Tempest right from the start, except for his stubbornness about thick wings.