It's official...

[gripen]

Originally posted by Karnak

Any ways, all kind of moot given that Kurfurst just posted data that confirms what I understood to be the case originally.  That the Merlin 266 is a Merlin 66 built in the USA and with American tooling.

Please check the source I claimed above.

gripen

[Crumpp]

Why don't you just compare speeds at 1st and 2nd FTH in the graph you posted.

I have Gripen.  That is why I posted it.  Maybe the "1" and the "2" have you confused.

The lower FTH is the faster of the two at all altitudes.

Feel free to add some graphics to it.  Maybe your eyes see something different in your world.

All the best,

Crumpp

[gripen]

Crumpp,
Well, at least according to my eyes the Fw 190 (with internal intake)  in your graph did about 680km/h at 2nd FTH 6500m and only 610km/h at 1st FTH 2000m.

BTW the date is 2.12.1943 so is it the V34?

gripen

[Kurfürst]

Originally posted by gripen
I'm quoting directly the RR listing of ratings from the appendix of "The Merlin in Perspective" by Alec Harvey-Bailey.

gripen

.... and I am qouting the RAF Air Intelligence's datasheet for British and enemy aircraft, from February 1945.I'd rather trust a primary source over a secondary one which may have printing errors, or simply the author is in error.

I just checked Jane's, too. They note the Merlin 266 is 'the same as the Merlin 66". Curious name... Packard-Merlin 266. Must be a concidence.

Guys, stop arguing with Gripen. We already have threads that turned into 15+ page of nonsense trying to convince him. It's hopeless. it would be taxing to read another 30+ pages of gripen repeating the same while being in conflict with his previous statements and completely ignoring/dismising everything that disproves him, and not backing up himself a single time.

We're loosing focus on the subject because of a single partisan who sits behind a 15-feet thick concreate wall against all reason, observing the world on a 9-feet long telescope with 200x zoom.

We had enough of this. Lone partisans don't need to be fought.

[Crumpp]

Any ways, all kind of moot given that Kurfurst just posted data that confirms what I understood to be the case originally. That the Merlin 266 is a Merlin 66 built in the USA and with American tooling.

That is exactly what Morgan and Shacklady say as well.  The FTH match up exactly with the Merlin 66.  It says the code was changed to keep them straight in the supply system because some of the peripheral fittings were different.

It is a non-issue then.

Well, at least according to my eyes the Fw 190 (with internal intake) in your graph did about 680km/h at 2nd FTH 6500m and only 610km/h at 1st FTH 2000m.

Good lord Gripen.  The line with the lower FTH is the faster one at all altitudes.  That is why they put the numbers on the chart.  So you look and see which line is which.  

Guys, stop arguing with Gripen.

Good advice.

All the best,

Crumpp

[gripen]

Originally posted by Kurfürst
.... and I am qouting the RAF Air Intelligence's datasheet for British and enemy aircraft, from February 1945.I'd rather trust a primary source over a secondary one which may have printing errors, or simply the author is in error.

The source I quote has direct copies of original RR spec sheets in the appendix.

gripen

[Kev367th]

Code change was mainly because of the different tooling required, British measument system vs the American measurement system.
Like metric v imperial today. (mm v inches)

[Karnak]

Originally posted by Crumpp
Karnak, you are one of those whose opinion I do value.  I understand what you are saying but I do not think just raising the FTH alone is the reason for the gains.  Unless it is a significant FTH gain to a much higher altitude and thinner air.

Yes, looking at Gripen's numbers, even though they seem pretty well countered now they still work to play with, the Merlin 66 would be producing 90hp more than the Merlin 266 with an altitude difference of only 3,400ft and that is not much different in terms of thinning the air.  That does seem that it would not produce much difference whereas the Merlin 61's 11,000ft difference would be quite significant.

[Crumpp]

Code change was mainly because of the different tooling required, British measument system vs the American measurement system.

That makes perfect sense.

Yes, looking at Gripen's numbers, even though they seem pretty well countered now they still work to play with, the Merlin 66 would be producing 90hp more than the Merlin 266 with an altitude difference of only 3,400ft and that is not much different in terms of thinning the air. That does seem that it would not produce much difference whereas the Merlin 61's 11,000ft difference would be quite significant.

Exactly!  Yes in theory raising the FTH alone will increase speed.

All the best,

Crumpp

[gripen]

Originally posted by Crumpp

Good lord Gripen.  The line with the lower FTH is the faster one at all altitudes.

You are mixing FTHs and different intake systems. Both intakes, internal and external, have same gearing ratios. And both lines show that the plane is faster at 2nd FTH than at 1st FTH.

gripen

[Nashwan]

Crumpp, I had a look in Spitfire The History for W3248, and I found something that I think explains the "greatly superior" 109G. I don't think it applies to rolling or turn rates, in fact I think someone has got confused, and it doesn't refer to W3248 at all.

From the book, page 157:

THE CLIPPED WING VB

Prototype for the clipped wing Spitfire VB can be considered to be W3248 and this variant was developed for low altitude duties, appearing in all war theatres. In the Middle East local modifications resulted in wooden tip fairings with more rounded profile than those fitted in England. In the fighter reconnaissance (FR) role several Spitfires, including EP878. were fitted with an oblique camera behind the cockpit. All skin joints were taped over and other blemishes removed and the whole aircraft highly polished. Engine supercharger blades were also cropped in an effort to increase speed. Several FR VBs were operated by No 40 Squadron of the SAAF during the fighting and chase of the Afrika Korps after the Second Battle of El Alamein in November 1942.

Production of the Mk V continued until the latter half of 1943, with Castle Bromwich building their last example-MH646- in August, and Westland the following October when they rolled out EF753. These models were very different from the original Mk Vs by having metal covered ailerons, an inertia weight on the elevator control system, modified horn balance to elevator. Engines included the Merlin 45, 46, 50, 50A, 50M, 55, and 56.

An interesting Mk VB was EN830 of No 131 Squadron which, whilst flying over France in a sweep on a dull November day. was intercepted and made a forced landing in a practically undamaged state. It was repaired and painted in standard Luftwaffe fighter splinter camouflage of dark and light green upper surfaces and blue under surfaces. It was coded CJ+ZY and seconded to Daimler Benz for the installation of an l,475hp DB605A engine. Armament was recovered and many minor modifications carried out. An example was the carburetter air intake installed on the port side of the engine cowling.
During trials the Mk V was no match for the BflO9G as the following figures demonstrate, but it is interesting to note that its climb rate to 19,000ft was far better than that of the German aircraft. It must be borne in mind, however, that the Spitfire's armament would have added 600 lbs dead weight.

SPITFIRE (AUW6550) Me109G (AUW6054)
Max speed s/l   300 mph   316
Max speed @ 22,000ft   379 mph   385
Rate of climb to 19,000ft   3,540 f/min   2,520

The test vs the 109G refers to EN830, which was captured by the Germans, fitted with a DB 605, and stripped of armament. It seems to much to be a coincidence that they talk of a Spit V tested with 600 lbs armament removed right next to discussion of W3248's roll rate.

[Kurfürst]

I guess the 'greatly superior 109G' part that ticks off poor Nashwan comes from the simple fact that even the possibly worst variant of the 109F/G was at 30-70 kph faster than the Spitfire V at altitude or even more at the really high altitudes, which let's face it was the mainstay of the RAF Spitfire squadrons,the MkIX being just as 'common' as the Me 262 until mid-1944.

They must have felt they're chasing jets anywhere over the MkVs modest critical altitude. There was no 'fight', either the 109 choose to engage the Spit or it didn't. Hell even that poor G-6 cruised as fast as the MkV's all-out.

[Crumpp]

It seems to much to be a coincidence that they talk of a Spit V tested with 600 lbs armament removed right next to discussion of W3248's roll rate.

You could be right.  I took the paragraph about the captured Spit Mk V to be an interesting side note.

Since the chapter is on clipped wing spits, I would assume EN830 had clipped wings.   Otherwise it seems an interesting but rather silly footnote to include in the THE CLIPPED WING VB section.

Either way the tactical trials of a clipped wing spitfire are on the way.

All the best,

Crumpp

[Guppy35]

Originally posted by Crumpp


You could be right.  I took the paragraph about the captured Spit Mk V to be an interesting side note.

Since the chapter is on clipped wing spits, I would assume EN830 had clipped wings.   Otherwise it seems an interesting but rather silly footnote to include in the THE CLIPPED WING VB section.

Either way the tactical trials of a clipped wing spitfire are on the way.

All the best,

Crumpp

EN830 did not have clipped wings.  That section is written poorly in Spit the Hist.  There is no transition from mentioning the clipping of the one Spit Vb to talking about the captured Vb

[Kurfürst]

Indeed :