4950ft/m. 452mph @ 19,685ft. So no a mark XIV couldn't run circles around a G-10.
Spitfire + Sabre: any facts/opinons?
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Edgar Brooks
Senior Airman
They had to do no such thing; the only Spitfire with a contraprop was the 21. Not all the airframes had one, and many were converted back (easily) to a standard 5-blade unit. The wider tracking of the 21-series took care of the ground handling, as well.
If the Sabre lacked power at height, what would be the point of putting it in an escort fighter, which needs all the height it can get, and needs to be able to fight on level terms, at that height?
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According to various sites that I frequent, the Standards for a Spitfire Mark XIV are:
~ "S" gear 439mph @ 24,500ft
~ "M" gear 404mph @ 11,000ft
~ Climb rate of 4,580ft/min
wuzak
Captain
Because the Griffon was in the Spitfire before the Mustang was combat proven?
davebender
1st Lieutenant
US Warplanes
618 Mustang Mk.Is were produced for Britain during 1941 at the Inglewood, California plant. I've got to assume they were in RAF service during 1942.
When was the first RR Griffon engine installed in a Spitfire airframe?
618 Mustang Mk.Is were produced for Britain during 1941 at the Inglewood, California plant. I've got to assume they were in RAF service during 1942.
When was the first RR Griffon engine installed in a Spitfire airframe?
Jabberwocky
Staff Sergeant
The RAF only got 30-odd Mustangs by the end of 1941, most delivered in November/December.
First Mustangs entered squadron service for the RAF in January 1942, flying their first combat missions in February and scoring their first kills in May.
First Griffon powered Spitfire flew in November 1941. The Mk XII entered squadron service in February 1943, flying their first combat missions and scoring their first kills in April.
Shortround6
Major General
First Mustang combat operation by a British squadron was on May 10th 1942. First Mustang arrived in England Oct 24th 1941, in a crate. Sea voyage from San Diego via the Panama Canal rather slows down deliveries.
First Spitfire prototype with Griffon engine (MK IV) flies in Nov 1941. 750 Griffon powered Spitfires were ordered on August 23, 1941 but none of this order were completed with Griffon engines.
Second Spitfire prototype with Griffon engine (MK XX) flies in Aug 1942. with a Griffon II single stage engine, it is later rebuilt with a two stage engine to become the prototype Spitfire XXI.
P-51B is ordered into mass production in Jan 1943.
First P-51B comes of the production line a the beginning of May 1943.
Griffon powered Spitfire XIIs start to enter squadron service in the Spring of 1943.
Second MK 21 prototype first flies in July 1943.
First Merlin powered P-51B arrives in England in Sept 1943.
First Spitfire prototype with Griffon engine (MK IV) flies in Nov 1941. 750 Griffon powered Spitfires were ordered on August 23, 1941 but none of this order were completed with Griffon engines.
Second Spitfire prototype with Griffon engine (MK XX) flies in Aug 1942. with a Griffon II single stage engine, it is later rebuilt with a two stage engine to become the prototype Spitfire XXI.
P-51B is ordered into mass production in Jan 1943.
First P-51B comes of the production line a the beginning of May 1943.
Griffon powered Spitfire XIIs start to enter squadron service in the Spring of 1943.
Second MK 21 prototype first flies in July 1943.
First Merlin powered P-51B arrives in England in Sept 1943.
claidemore
Senior Airman
What's your source for those figures?
I know you said compare to G10, not G14, but I have no charts for G10 so I used G14. I could just as easily have used K4 @1.8 ata, and the Spit XIV would still come out ahead. There have been discussions many times before on this forum where arguments were made for combat use of K4's with 1.98 ata, and those protractors insisiting that it not be compared to the XIV @ 21 lbs boost. I prefer to compare apples to apples, so it's the Mk XIV @ 18lbs boost to the K4 (or G10 with same engine) at 1.8 ata. Any charts or reports you can share on the G10 would be much appreciated.
Of course none of this has any bearing on a Sabre engine on a Spit, but any discussion of a Spitfire tends to include comparisons of it's principle opponent the Messerschmitt, and so it should.
wuzak
Captain
Spitfire XIV prototype first flew in January/February 1943, and first production machine came off the line in October 1943.
The XXI, or 21, had the new, strengthened wing. The XX was the same as the IV, but renamed, IIRC.
wuzak
Captain
Changing the Mustang to the Griffon engine may only have been possible if Packard, or another US manufacturer, was building Griffons under licence. The production rate for Griffons was very much less than for Merlins.
claidemore
Senior Airman
I'm not aware of any increase in landing or takeoff problems with Griffon Spitfires compared to Merlin spits. The MkXIV was considered one of the best fighters in 1945, definately not obsolescent, and the Mk21/22 and Mk24 were yet to come! The Mk21 had the same basic airframe as the MkXIV, with the following improvements, redesigned stiffer wing, different and larger ailerons, and wider track undercarriage (by 7 3/4 inches). The Mk 22 was in use by RAF until 1955, the Mk 24 by RAF until 1952, and with the Hong Kong airforce until 1955.
As for fuel capacity, the Mk24 could carry up to 186 gallons of internal fuel (with wing tanks and two rear tanks), which is 120% increase over the Mk1's 85 gallons of fuel.
For me, an airframe that is outdated would be one that could not use the latest improvements in engines or weapons, or could not match the performance of other fighters in use at the time in question, and the Spitfire was always able to do that.
Shortround6
Major General
Thank you for the MK XIV information. One book I have claims that DP845 was the airframe that was the MK IV which was redesignated MK XX before becoming a MK XII prototype.
DP851 was supposed to be the MK 20 (which, I guess is NOT a MK XX !!) with the single stage engine and became a MK 21 when re-engined with a two stage engine.
My apologies for the confusion.
wuzak
Captain
I think that is correct.
The MkIV designation was changed because another project was using or had used that identification, and the name was changed to avoid confusion.
Edgar Brooks
Senior Airman
There were two Spitfire IV airframes, DP845 DP851, which were powered by the Griffon II. There were engineering aspects of the Griffon II which Rolls-Royce didn't like, so it was taken back, and redesigned into the Griffon III, which powered the Spitfire XII; DP845 became the XII prototype, and the Mark IV was renumbered XX (along with the planned name-change to "Victor") before the prototype flew.
Supermarine had an understandable habit of issuing Mark nos as soon as work started on the drawings; if you ever get a chance to look at a Spitfire drawing, its designation consists of 5 numbers, the first three of which denote the Mark (e.g. 300-- = Mark I,) and the susequent pair denote the area (e.g. 08 = wings.) The Mark XII was Type 366, so drawings were 366--, followed by the Sheet no., in the series.
In January, 1944, the Air Ministry tried to preempt any more confusion, by issuing, in advance, blocks of Mk. nos, so 21-30 were Griffon-powered, 31-40 were Merlin-powered (and never used,) 41-50 were Merlin or Griffon-powered Seafires.
The Mk.IV/XX designation disappeared largely because its original engine no longer existed, and, when the P.R.IV got its designation, Mark XII was the next number, once the Griffon III came available; DP851 went on to become the prototype 21, and, following its crash, PP139 took over the task. At some stage, "Victor" was dropped, and "Spitfire" continued.
Edgar
Supermarine had an understandable habit of issuing Mark nos as soon as work started on the drawings; if you ever get a chance to look at a Spitfire drawing, its designation consists of 5 numbers, the first three of which denote the Mark (e.g. 300-- = Mark I,) and the susequent pair denote the area (e.g. 08 = wings.) The Mark XII was Type 366, so drawings were 366--, followed by the Sheet no., in the series.
In January, 1944, the Air Ministry tried to preempt any more confusion, by issuing, in advance, blocks of Mk. nos, so 21-30 were Griffon-powered, 31-40 were Merlin-powered (and never used,) 41-50 were Merlin or Griffon-powered Seafires.
The Mk.IV/XX designation disappeared largely because its original engine no longer existed, and, when the P.R.IV got its designation, Mark XII was the next number, once the Griffon III came available; DP851 went on to become the prototype 21, and, following its crash, PP139 took over the task. At some stage, "Victor" was dropped, and "Spitfire" continued.
Edgar
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- Source: Radinger/Otto/Schick: "Messerschmitt Me 109", volumes 1 and 2, Eric Brown: "Testing for Combat". Mercedes-Benz AG, Archives, Stuttgart, Germany
Some G-10s used DB 605 DC and Improved 605 DM, standard MW-50 equipment, up to 2000 PS, C3 fuel. Compared to the two-stage two-speed and turbo-charged engines of the western powers it is im-pressive what Daimler-Benz could achieve with the single-stage DB 605. By comparison the two-stage Merlin engines had a rated altitude ranging from approx. 5.8 km to 7.9 km. At the combat altitudes of 1944 the performance of the DB 605 rivalled that of the high altitude Spitfire and the Mustang. While the conventionel mechanical superchargers consisted of one or two compressors driven via a two-speed gear, Daimler-Benz utilised an ingenious barometricly controlled hydraulic clutch which adjusted the compressor speed and thus the charging of the engine according to the needs at a given altitude. The conventional method results in a relative loss in efficiency below rated altitude, because the compressor uses energy to produce surplus charging.I know you said compare to G10, not G14, but I have no charts for G10 so I used G14. I could just as easily have used K4 @1.8 ata, and the Spit XIV would still come out ahead. There have been discussions many times before on this forum where arguments were made for combat use of K4's with 1.98 ata, and those protractors insisiting that it not be compared to the XIV @ 21 lbs boost. I prefer to compare apples to apples, so it's the Mk XIV @ 18lbs boost to the K4 (or G10 with same engine) at 1.8 ata. Any charts or reports you can share on the G10 would be much appreciated.
Of course none of this has any bearing on a Sabre engine on a Spit, but any discussion of a Spitfire tends to include comparisons of it's principle opponent the Messerschmitt, and so it should.
Shortround6
Major General
This has been gone over many times before and it not anywhere near so amazing as many people think. The "hydraulic clutch" is little more than the torque converter from an automatic transmission. What you are comparing is a single speed transmission with a torque converter to a two speed transmission with a manual clutch. The torque converter "slips" to provide low gear or more properly a range of low gears. When it is locked up it can provide no higher gear ratio than a two speed transmission and it certainly can't drive the the compressor faster than the design of the compressor will allow for and get any benefit. It certainly will NOT turn a single stage compressor with a limit of, say, 3.2 Pressure ratio into a compressor with a 5.1 compression ratio (which is what the 2 stage compressor on a Merlin 61 could do) A two stage compressor will take less power to compress the air to a given pressure ratio and it will heat the intake charge less while doing so. The Two stage is heavier, bulkier and more expensive though. It is also harder to get the airflows to match through the superchargers without choking or surging.
The hydraulic coupling, while offering a more efficient speed or the impeller at low altitudes was more expensive than a two speed drive and while the impeller and intake system were operating more efficiently the hydraulic coupling itself , at maximum slip, could be using up 40-60hp in friction and truning it to heat that the engine oil system had to get rid off through the oil cooler. Some engines with these coupling used a separate oil system and not the engine oil in which case they need their own oil tank/cooler.
For 1940's technology it was SUPER impressive. The barometricly controlled hydraulic clutch gave much more 'flexibility' at all altitudes. My hydraulic clutch in my Skidoo slips like crazy (like its designed too).. but I promise its faster then most 100K+ ferraris at 0-60mph / 0-100mph / 0-135mph (top speed).
davebender
1st Lieutenant
Not sure what that means.
However if you look at a torque curve chart for DB601 and DB605 engines it's very smooth over a broad altitude band. Compared to most engines with 2 stage superchargers which had a jagged torque curve. The smooth torque curve provided a significant advantage for fighter aircraft when using Boom Zoom tactics.
However if you look at a torque curve chart for DB601 and DB605 engines it's very smooth over a broad altitude band. Compared to most engines with 2 stage superchargers which had a jagged torque curve. The smooth torque curve provided a significant advantage for fighter aircraft when using Boom Zoom tactics.
