ChernKStewfanThe MS 406 had a radiator that could be lowered/raised (or extended/retracted if one prefers) depending on drag/cooling requirements. It seemed to be more trouble than it was worth, because on the MS 410 (upgraded 406) and other developments the radiator assembly was fixed.
ChernKStewfanThe only thing that I have to judge from are the few color photos (of the one that’s been preserved shown earlier in the thread, which may or may not be original paint), and black and white photos, which unless one’s sure of what contemporary color schemes were for a type of aircraft, it’s a case of best guess.
After seeing some HQ photos of the preserved Vengeance, it looks like it’s earth brown instead of sea grey–most RAF fighters had that color scheme in the South Pacific. But most aircraft that served in India and most in the Pacific Theater during late World War II adopted the ET color scheme or either sea grey/earth green/sky, or, especially PR aircraft, silver, though Mosquito fighters in the Pacfic also used an overall silver color scheme.
However, B&W photos hare still deciviing at times due to quality–some DH Hornet photos make the color scheme look like silver upper/dark blue lower, when it’s actually sea grey upper and cerulean blue (AKA PRU blue) undersides. The latter was used in post war by PR and high altitude fighter aircraft in the RAF.
ChernKStewfanAs far as Vengence color schemes, since most were used in South East Asia, most probably had the “SEAC” color scheme for single engined fighters, of earth brown, earth green upper surfaces and sky undersides (think pre-1941 RAF Fighter Command colors), though in India, most RAF aircraft that flew during the day had the standard European Theater color scheme of dark sea grey, earth green and sky.
ChernKStewfanActually, the Spitfires pictured are Mk Vs. The Vokes filters and coupled exhaust stubs are the giveaways usually. The Mk VIII and Mk IX Spitfires had much smaller filters built into the supercharger intake (looks like an extended intake, sort of like what tropicalized Mosquitoes had). Mk VIIIs also had retractable tail wheels.
ChernKStewfan6 vs 12 stubs help, but it’s not an absolute for ID’ing a Mk V vs a Mk IX. Best chance, unless you can look at the mfg’s data plate, is the underwing radiators–on the Mk V, they an oil cooler under the port wing and a water radiator under the starboard. On the Mk IX, both intakes are the same size and shape because the Merlin 60 series had a two stage supercharger, and hence an intercooler was housed in a housing that shared the oil cooler.
ChernKStewfanThe conjoined/merged pipes were also fitted on the Hornet for much the same reason as on the Mosquito–the inboard stubs would’ve blown hot exhaust almost directly into the radiator intakes.
The single stage Mosquito models (PR I/IV, B IV, F/NF II, NF XII/XIII/XVII/XIX, FB VI/XVIII) had Merlin 21, 23 or 25 engines (or Packard built equivalents for those build in Canada or Australia), and all except the Oz-built FB 40 had the jointed rear pipes. The FB 40 had 6 pipes outboard/5 inboard.
The two stage Mosquitoes (B/PR IX/XVI, PR 34, B 35, F/NF XV, NF 30/36/38) had 6 on each side because of the engine nacelles being 9 inches longer, allowing room for 6 stub pipes.
In the case of the Hornet, though it had two stage Merlins, it had 5 pipes on each side for the reasons explained above, as it’s engine nacelles were shorter than those of the two stage Mosquitoes (the Mosquito was designed originally around single stage Merlins, while the Hornet had it’s engines designed essentially for it–namely the downdraught injector carb sort of like what most Allison V-1710s had, but was a British made Rolls/SU carb based partly on the license built Bendix/Stromburg units fitted to most Merlin 60 series engines/all Packard V-1650 variants, and was more advanced than the early Bendix carbs).
And as pointed out, the FB 26 (DHC license built FB VI) had Packard V-1650 Merlin 225 engines, based on the Rolls-Royce built 25 as it’s original engines, and the 25/225 are interchangeable on the Mosquito.
ChernKStewfanIt also should be mentioned that the Ford Mustang wasn’t named after the horse, it was named after the fighter plane that the RAF (and ultimately the USAAF) named after the horse 😉
ChernKStewfanSomeone with better knowledge on the subject would probably correct me or elaborate more on it, but the Jumo 211 was designed primarily as a “bomber” engine, used mostly for medium bombers and night fighters, where torque was of equal or more importance than top end power. Hence, as it was designed for larger, usually multi-engined aircraft, the 211 wasn’t well suited for a single seat fighter.
Also, it must be considered that the most powerful version of the 211 made 1350-1400 bhp, while the DB 605 made from 1450-2000+bhp. So the power loading figures were probably different and not in the favor of the S-199 with the Jumo engine, which lacked the power of the DB 605. The Jumo 213, which wasn’t much heavier than the 211 from which it was developed but capable of making far more power (more than that of most DB 605 variants) would’ve been a better choice, but it wasn’t in any supply, while the S-99 (Czech built Bf-109G with the 605) used up remaining stocks of the 605s still stockpiled in the former Czechoslovakia. And it wasn’t like what Hispano Avicon in Spain did with their license built Me-109s (which were fitted with Rolls-Royce Merlin 500 engines) or how Fiat got the G59, by fitting Merlin 600 engines in G55 airframes (the G55 used both German and Italian built DB 605s), because of Soviet domination of most of eastern Europe by that time. And, for whatever reason, the Czechs couldn’t get Klimov M-105 or VK-107 engines (much modified Russian built Hispano-Suiza 12Y-based engines, which Avia also built the 12Y in prewar years. Also, the M-105 in it’s most powerful form only made 1300-1360bhp, but it was much lighter than any of the German designed V12s). So the Jumo 211 was what they had to make do with.
Either way, the Me-109 airframe and Jumo 211 engine was a bad mismatch in terms of performance. And having to mount MG-151 cannons under the wings (since the Jumo 211 had no provision for an engine mounted cannon) added drag and weight, the latter now helping with the 109’s fairly high wing loading for the time in addition to the engine being seemingly underpowered and not suited for a single seat fighter.
ChernKStewfanThis goes back to a thread I posted here a while back asking about the Merlin variants. If the engine was a 502, was it based on the 25 and was a civil-rated single stage Merlin variant (the 600 series were based on a civil rated 100 series engine and had a two speed/two stage supercharger)?
ChernKStewfanI don’t think that the PR9 was ever fitted with the 20mm Hispano-Suiza cannon pack. I do remember seeing a PR9 fitted with a similar belly pack at Avia de ja vu (a link on airwar.ru) and it seemed to be for some electronic equipment.
Did Canberras carry some type of belly pack with electronic surveillance equipment operationally? The item in the photo seems to be similar to what I saw fitted experimentally to a Canberra PR9 in the photo I mentioned, but I’m not aware that it was ever used on operational sorties.
ChernKStewfanThe story about the Packard V-1650/Merlin 266 seems to have been perpetuated into the Spitfire lore, since various sources have stated that the repositioned intercooler caused the bulge. Since the Mk XVI was the first to have them and they had the Packard 266 in them, that’s probably where the legend started, as opposed to a production method change at Castle Bromwich you mentioned, as that’s where most Mk IXs were made, as well as it seems the XVI.
ChernKStewfanJust a couple of points. First the Merlin two stage supercharger deal.
All Merlins from the 60 series onward did use two stage superchargers, but there were sub-variants within the 60 series that were set up to give their best performance at various altitudes. Hence Spitfire VIIIs and IXs were often given the HF, LF and F designations (high alt fighter, low alt fighter and general purpose fighter respectively). The Merlin 61 was a general purpose engine, the Merlin 63 and 70 were high alt engines, and the 66 was a low alt engine. There was no such distinction with the Griffon, as the Griffon were given superchargers with a broader band of optimum performance. What the differences were I don’t know (this is from a Wikipedia article about Spitfire specs that does mention this and why there were no LF, F, or HF Griffon Spitfires).
And as far as RR299, the accident report stated that one engine was a 25 and the other was a 225. I don’t know where a link to the report is, but it was published and hopefully someone could advise us on where to find it. For the record, KA114 does have British built 25s in both nacelles that were installed during it’s restoration (FB26s–DHC built FB VIs–like KA114 did have 225s as stock).
And for the differences between the 266 and 66, it seems that on the Packard version, the intercooler was mounted differently compared to the R-R version (mounted up higher on the engine assembly), and that caused that bulged cowling–most late production Spitfire IXs had them, too, so that shouldn’t be used as an ID feature between an IX and a XVI.
And I’m quite surprised at how similar the Packard V-1650 and the Rolls-Royce Merlin are, since I heard that there were some fairly significant differences–major assemblies were similar or if not identical, but detail specs and parts were different. Instead, it seems that there’s just a few minor ones, mostly prop shaft types and minor fittings to suit various items. Like the prop drive shaft, the V-1650 was set up to use Curtiss Electric (P-40 F/L) or Hamilton Standard propellers (Merlin powered Mustangs), while the 266 had to be set up to use a Rolls-Bristol (Rotol) prop, and it seemed to be a simple change of drive shaft.
ChernKStewfanThe only real equivalent between the R-R and Packard build Merlins is role and structure. Hence, the single stage and two stage SC engines should be of comparable weight within a certain tolerance-perhaps about 20 pounds or so at most based on my readings of Jane’s All The World’s Aircraft 1946 (sold in NA as Jane’s Aircraft of World War II–as Bill Gunston points out in the forward he authored in the present day edition, the latter title is a bit misleading).
The problem with determining the precise details is Rolls-Royce’s own numbering system. R-R initially gave the Packard V-1650 family numbers that were unused within the single- and two stage Merlin families. Hence, the V-1650-1 was the Merlin 28 to Rolls-Royce, and the V-1650-7 was the Merlin 69. All The World’s Aircraft, IIRC, did say that the “69” was based on the Merlin 66 as a general purpose engine for the P-51D/K Mustang (Mustang IV in RAF service). However, the Merlin 66 was a medium altitude engine used in low altitude/medium altitude versions of the Spitfire VIII and IX, and this the V-1650-7 and the Merlin 66 might have run differing settings for the supercharger (only late in the Merlin’s life, as far as at least the British built versions, did they receive two stage superchargers that gave excellent performance throughout a very wide alt. regime–though all two-stage Griffon’s had them. I don’t know of the two-stage V-1650s had them).
Then, very late in the war, did Rolls-Royce give the Packard V-1650s their own number range, with the “200” series. Problem with that is that the Merlin 69 and 266 were based off the Merlin 66 per most lists that I’ve read. So either they’re the same engine, with late examples given the 266 number, or the 266 was build to R-R/RAF specs as far as supercharging and other items.
However, that doesn’t make sense, because though all versions of the Merlin–whether or not built by Packard or Rolls-Royce–weigh the same basically and are built to the same dimensions, not all parts would interchange due to differing material specs and manufacturing practices. For an infrantry weapon, think of it as being like the “inch pattern” and “metric pattern” FN FAL rifles, where whole sub-assemblies would interchange, but detail parts often won’t.
The Packard engines had a different arrangement for the engine accessories at the rear of the engine, and that caused difficulties for placing the Packard built engines into Spitfire airframes without modifying the Spitfire’s engine mounts (I believe that the issue was the intercooler’s mounting, which is why Spitfire XVI’s had a unique upper engine cowling). It caused an issue with installing engines into airframes on occasion, as mentioned with the Spitfire XVI. However, many Mustangs use R-R built Merlins, apparently without modification to the engine mountings. And the DH Mosquito RR299 was reported to have had installed in it a Merlin 25 (R-R built) in one nacelle, and a Merlin 225 (Packard built) in the other when it crashed.
The biggest difference between the US and British Merlins seems to be accessory arrangement, though this also happened with the R-R built Merlins (the 100 series, especially the 130 series built primarily for the DH Hornet), which caused some issues for some British aircraft adapted to take the Packard V-1650 engines.
However, the engines all weighed the same basically, at least within a tolerance, provided that they’re at least within the same single stage or two stage families. However, the key phrase is “within tolerance”, because of minor manufacturing and material differences, especially with the accessories for the engines.
ChernKStewfanLooks like part of a Mosquito NF or Sea Hornet NF/PR exhaust manifold. Both used a large collector cylinder and large fishtail exits. Early NF Mosquitoes had two exits, later versions and the Sea Hornet NF/PR aircraft had four exits. Without the whole manifold being assembled, I can’t conclude if it’s an early or late Mosquito NF, but the Sea Hornet NF and PR aircraft for sure had four exhaust exits on their “flash suppressor/flash hider” exhaust.
I read that pilots and ground crew for NF Mosquitoes weren’t particularly fond of these exhaust systems, especially early versions for some reason (exhaust back pressure sapping engine power (?), and maybe a pain to work on for engine mechanics?), but I’ve never heard such criticism for the later Mosquito and Sea Hornet versions. But early NF Mosquitoes and the early bomber and PR variants, as well as the FB variants (FB VI and license built DHC and DHA versions) had simple exhaust shrouds over the standard exhaust, either as a field conversion or were new from the factory as such.
ChernKStewfanI think that all Merlin engines from the Mk XX onwards until the 60 series used SU carbs that were fitted with “Miss Shilling’s Orifice” that fixed most of the negative G issues. Later 60 and most 100 series Merlins used a license built Bendix-Stromburg pressure carb (also called an injector carb, not to be confused with fuel injection, including early throttle body systems), with the original American item fitted to the Packard V-1650. The Merlin 130 series had a SU injector carb of British design that had little to do with the Bendix pressure carbs.
Nevertheless, the neg-G carb issues didn’t cause RR299’s accident, it was an issue of a mechanical failure that caused the fuel starvation/power loss.
Sign In
