Merlin Bf-109

[megan]

Just been reading a paper which suggested, or hinted, that a Bf-109 was re-engined with a Merlin for test purposes during the war. Not heard of it previously, anyone with info?

Not referring to the later Buchon.

[treadigraph]

Never heard that one, but there is a pic out there of a captured Spitfire with DB605 installed.

[blue up]

Didn't the early 109 use a Kestrel engine or something like that? Also, there's the Hispano Buchon.

[blue up]

Prototypes[edit]

Messerschmitt Bf 109 V1

A drawing of the V1 prototype
Design work on Messerschmitt Project Number P.1034 began in March 1934, just three weeks after the development contract was awarded. The basic mock-up was completed by May, and a more detailed design mock-up was ready by January 1935. The RLM designated the design as type "Bf 109," the next available from a block of numbers assigned to BFW.[6]

The first prototype (Versuchsflugzeug 1 or V1), with civilian registration D-IABI, was completed by May 1935, but the new German engines were not yet ready. In order to get the "R III" designs into the air, the RLM acquired four Rolls-Royce Kestrel VI engines by trading Rolls-Royce a Heinkel He 70 Blitz for use as an engine test-bed.[nb 2] Messerschmitt received two of these engines and adapted the engine mounts of V1 to take the V-12 engine upright. V1 made its maiden flight at the end of May 1935 at the airfield located in the southernmost Augsburg neighborhood of Haunstetten, piloted by Hans-Dietrich "Bubi" Knoetzsch. After four months of flight testing, the aircraft was delivered in September to the Luftwaffe's central test centre at the Erprobungsstelle Rechlin to take part in the design competition.

In 1935, the first Jumo engines became available so V2 was completed in October using the 449 kW (600 hp) Jumo 210A engine. V3 followed, the first to be mounted with guns, but it did not fly until May 1936 due to a delay in procuring another Jumo 210 engine.

[ian16th]

Didn't the ME 109's built in Spain after WWII have Merlin's fitted?

These were also the a/c used in the movie of the Battle of Britain.

[chevvron]

What I would like to know is what happened to the Heinkel He70?
Did it ever reach our shore?

[blue up]

Yes. Rolls used it as an engine test bed. Remarkably fast machine.

In a letter to Heinkel, written after seeing the aircraft perform with the Rolls Royce Kestrel engine fitted, R. J. Mitchell said:

We, at Supermarine Aviation, were particularly impressed, since we have been unable to achieve such smooth lines in the aircraft that we entered for the Schneider Trophy Races....

In addition to this, we recently investigated the effect that installing certain new British fighter engines would have on the He 70, We were dismayed to find that your new aircraft, despite its larger measurements, is appreciably faster than our fighters. It is indeed a triumph.

[ICT_SLB]

I'm not sure where I saw it but the Heinkel's elliptical wing is credited with being the source of the Spitfire's elegant planform - certainly the older fixed gear "Spitfire" prototype didn't have it!

[megan]

the Heinkel's elliptical wing is credited with being the source of the Spitfire's elegant planformYou see the claim oft made, but not really credible when you read the development steps of the wing. Best illustrated by the following scans. Mitchell had used the elliptical wing as early as July 1929 on a six engined flying boat designed to meet Air Ministry Specification 20/28 which had been issued in January 1929.

Beverley Shenstone, RJ Mitchell's aerodynamic advisor denied that the Spitfire wing was copied from the He 70. Shenstone said:

It has been suggested that we at Supermarine had cribbed the wing shape from that of the He 70 transport. This was not so. The elliptical wing had been used on other aircraft and its advantages were well known. Our wing was much thinner than that of the Heinkel and had a quite different section. In any case it would have been simply asking for trouble to have copied a wing shape from an aircraft designed for an entirely different purpose.

Shenstone said that the He 70's influence on the Spitfire design was limited to use as a benchmark for aerodynamic smoothness.

[SPIT]

Hi
I thought the subject was the Me-109 NOT the He-70 :mad::mad:

[VictorGolf]

Not directly related but an Me 109 has recently flown in the USA with an Allison V-12. Looks very much like a Benz engined one.

[Amiri01]

I recall from many years ago a photo in a book, possibly William Greens "Warplanes of the Third Reich" where in the '109 section, there was a black and white photo of a dark coloured '109 fitted with a Merlin. The spinner was lower than on the DB powered '109s and the cowling had a marked droop along its top surface. It looked ugly compared to the DB powered version.

I may be wrong as it was close to 40 years ago when I admired the book and the aircraft in my high school library. Perhaps if someone has the book, they could check for the photo that I recall?

[DHfan]

In my case it's 50 years+ since I saw the book but I'm pretty sure the picture you saw was the Spitfire with the DB engine.

As the Merlin is upright and the DB is inverted, the reduction gear means the spinner has to be lower on the DB, not the other way round.
See the Buchon for an instant example.

Edit: Google EN830. I'm sure the picture that comes up in at least the first few links is the one in the book.
I wouldn't have remembered the title but I'm pretty sure you're right about the author. We had several of his books in my school library too.

[Amiri01]

In my case it's 50 years+ since I saw the book but I'm pretty sure the picture you saw was the Spitfire with the DB engine.

You are correct. That is the photo I recall. Spitfire with DB engine... My mistake...

[El Bunto]

Off a tangent from Merlins, but one early Bf 109 prototype was converted in 1938 with a P&W R1830.

Pprune won't let me link to an image, but search for "Bf 109 v21 radial"

Allegedly there was also a later conversion of a 109F with a BMW 801 radial but it's hard to separate fact from fiction there.

[blue up]

Tricycle undercart, 3 main gear leg (for heavy bombs) and even a V-tail version. Lots of odd-ball versions were built. Wasn't there a F-82 Mustang clone?

[bobward]

I've just had a look through Warplanes of the Third Reich, as well as the Harleyford Me 109 A famous German Fighter. Neither has the photograph the OP mentioned.

However, Harleyford does mention that th '109 prototype flew with a Rolls-Royce Kestrel engine. In addition, pictures of early 109's (B and C models) had a large radiator bath under the nose, so perhaps these might be why the OP thought of the Merlin?

Hope this helps a bit

[DHfan]

The OP has confirmed it was a Spitfire - EN830 to be exact - and not a 109.
We almost certainly saw copies of the same book. I'm still pretty confident about the author but after all this time I've no idea of the title.

I can guarantee it wasn't the Harleyford book about the 109. The Spitfire one was the only one I'd ever seen until three or four years ago when I picked up the one about the Lancaster in a charity shop a few minutes after it was donated.


Off a tangent from Merlins, but one early Bf 109 prototype was converted in 1938 with a P&W R1830.

Pprune won't let me link to an image, but search for "Bf 109 v21 radial"

Allegedly there was also a later conversion of a 109F with a BMW 801 radial but it's hard to separate fact from fiction there.

I'd never heard of it but that really doesn't look right.
Via one of the search links, it seems the one with the BMW 801 was the 109 X.

[megan]

From WikiBf 109X

After the success of the demonstration at the meeting of Zürich in 1937, Udet was receptive to the idea of developing an export version of the Bf 109 but with a different engine than the DB 601. The engine chosen was the P&W "Twin Wasp" SC-G of 1200 hp. The Messerschmitt company received a contract from RLM/LC on 13 June 1938 to fit the P&W Twin Wasp on the Bf 109 V21 (21st prototype) Werknummer 1770 (D-IFKQ). Even the maiden flight date is not known; it is established that Hermann Wurster flew it at Augsburg on 17 August 1939. In September 1940 it was part of the DVL (Deutsche Versuchsanstalt für Luftfahrt) at Brauschweig-Völkenrode with the Stammkennzeichen code KB+II. Its end is not known.

As the BMW 801 radial engine became available, a Bf 109F, Werknummer 5608, callsign D-ITXP was converted with a BMW 801 A-0. This aircraft became a prototype for the Bf 109X. The fuselage had a wider cross-section, and a new canopy was fitted. The wing tips were akin to that of the Bf 109E. The prototype was first flown by Flugkapitän Fritz Wendel on 2 September 1940, and the test flights continued despite troubles with the BMW 801A powerplant. Development was stopped in early 1942.A photo

https://web.archive.org/web/20071213021826/http://www.messerschmitt-bf109.de/display.php?lang=de&auth=e&name=version_display&fotonummer=4262

The F-82 clone, Bf 109Z-1, and 109X.

[Octane]

What was the difference in performance between a BF-109 and the Merlin engined Buchon?

[RedhillPhil]

https://defenceoftherealm.wordpress.com/2014/11/17/the-franken-spitfire/

[DHfan]

What was the difference in performance between a BF-109 and the Merlin engined Buchon?

I think that's a bit like "how long's a piece of string?".

Wiki appears to suggest the Buchon's slightly faster than a 109G, but doesn't say at what altitude, and has a substantially lower service ceiling.
It's also apparently heavier which, considering the DB605 has an even greater capacity than a Griffon, seems odd.

On balance, I think I'll stick with my first comment.

[ian16th]

The pub quiz piece of trivia is the the 1st and last Bf109's built, both had RR engines.

[El Bunto]

What was the difference in performance between a BF-109 and the Merlin engined Buchon?
Hard to say without the actual manuals but based on published information:

The Buchon ( HA-1112-M1L ) was about 100kg heavier than the 109G-2 on which it was based, but managed another 1,000ft/min initial climb given that it had nearly 200hp more at take-off. And a big four-bladed prop to deliver that.

Range seems to have increased by about 40% to 480 miles, but with no data on how that was achieved. German range data was usually based on a faster-than-Allies cruising speed, for the G-2 about 340 miles at 320 mph.

Buchon claimed 415 mph at 13,000ft, G-2 369 mph at 16,400ft. G-2 had the advantage of GM-1 boost at higher altitudes ( 400+ mph ) but I don't have any performance figures for the Buchon al higher altitudes.

Annoyingly as I was looking into this I just realised that William Green's lauded "Warplanes of the Third Reich" has translated all the original performance data into Imperial measurements, with no reference back to the original German numbers. Daft. So I've just had to use them here in the absence of another reference to hand.

[El Bunto]

Incidentally, my limited exploration of Spanish suggests that buchón means a bird that can swell its crop. Which makes sense since the Merlin-engined HA-1112 had a big 'throat' bulge versus the earlier Hispano-engined versions.

"Here comes bulgy!"

[DHfan]

I seem to recall reading it means pigeon but since my knowledge of Spanish is "I know nothing" I can't say whether it's right or not.

[megan]

It seems you are both correct. Buchón apparently means male dove, referring to the Pouter breed. The Pouter pigeons are domesticated varieties of the rock dove, Columba livia, characterized by a very large, inflatable crop.