German airframes, allied/foreign parts

Discussion in 'Aviation' started by tomo pauk, Jun 3, 2011.

  1. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Opposite from the another thread: what Allied/foreign ( = including Japanese, Italian etc) part would've you mate to German airframe in order to have a better plane?

    To start the ball rolling, I'd like to see Merlin 60s series mated to a Fw-190, for a great mid-war fighter.
     
  2. Glider

    Glider Well-Known Member

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    Griffon instead of the DB 605, unlimited high octane fuel, gyro sights when they could make a difference for a start.
     
  3. Lighthunmust

    Lighthunmust Banned

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    The superior American Nose Art!:lol:
     
  4. Readie

    Readie Well-Known Member

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    How about a Bristol Centaurus in a Ju88 ?
    Or
    A Merlin in a Macchi MC.202 Folgore?
    Cheers
    John
     
  5. johnbr

    johnbr Well-Known Member

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    #5 johnbr, Jun 3, 2011
    Last edited: Jun 3, 2011
    B29 with Db 604c with 3 stage 3 speed supercharger or FW 190 with a Griffin 130.The db 604c was also known as the x24.
     
  6. Mike Williams

    Mike Williams Active Member

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    Yes, gyro gun sights came immediately to mind for me as well. Allied gyro gun sights were very effective and I shudder to think of the additional allied losses if the Nazis had sights as effective.
     
  7. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Twin Wasps for Hs-129 - almost triple the power vs. Hs-129As.
     
  8. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Napier Sabre for Ju-88/188 - Moskito, pass auf!
    Western radar, plus a couple of Soviet 37mm cannons for a good measure.
     
  9. Shortround6

    Shortround6 Well-Known Member

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    At double the weight. Nothing was going to save the Hs 129 short of a new airframe. This like trying to put Twin Wasps in a Beech 18 :)
     
  10. tomo pauk

    tomo pauk Creator of Interesting Threads

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    Than we can compare the G&R engined Hs-129Bs with my proposal (single stage R-1830): a weight gain of some 10% for empty weight, perhaps 7-8% for max take off weight? In the same time having 2400 HP vs. 1400 for take off low level job (70% increase).
     
  11. Shortround6

    Shortround6 Well-Known Member

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    The weight gain is more like 500lbs per bare engine. or 11.2% except that you need larger engine mounts, exhaust system, cowling, engine nacelle (48in dia. engines don't fit well on nacelles made for 37in engines) bigger starters and of course the bigger, heavier propellers. you would be lucky to get away with a 1500lb increase in empty weight.
    Of course ALL of this is forward of the CG but some of this can be compensated for by the larger oil tanks and perhaps a reward shift in the fuel tanks which are going to have to be bigger to feed the bigger engines, at least if you actually want to use that extra power. Can't do to much though because the plane has to balance with both full and empty tanks.
    Your useful load is shrinking fast 55% of it was used up the engine swap with out allowing for more gas and oil and bigger tanks. Yes you can up the gross weight but that cuts your "G" limit without structural reinforcing, it will probably require beefed up landing gear (fortunately those larger nacelles give you plenty of room :)

    you might be able to get the plane up to 290mph or so, I wonder how much beefing up the wings and nacelles will need to handle the extra power and speed. Or do we increase the level speed but not the dive speed?

    A pair of Twin Wasps could easily suck 500lbs of fuel on a combat mission 20 minutes from base using max lean cruise settings for the 20 minutes out and back. They use around 30lbs a minute at take-off or military rating. Longer missions or more extended use of rich mixture settings will, of course require more fuel.

    The Germans could have made a nice ground attack plane using a pair of Twin Wasps. But it wouldn't have been a HS 129.
     
  12. Glider

    Glider Well-Known Member

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    Bristol Perseus 905 hp at a weight of 1025 lb compared to 720 hp at a weight of 904 lb seems a feasible option. Power to weight is up considerably and the weight could have been adjusted depending on the COG
     
  13. Tante Ju

    Tante Ju Banned

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    Nice thread both of them, and interesting suggestion!

    What would be the advantage of it? German aircraft manufacturers had access to their own equivalents of each of these (i.e. Junkers 213 or Daimler Benz 603 instead of Griffon, their EZ series gyroscopic predictor sights, their own high octace fuel etc.), sometimes even at an earlier date.. although I am sure they would have liked unlimited fuel, problem being none had such 'item' at their disposal! Also I believe using the Griffon would be actually disadvantagous, as it consumed a lot more fuel than the engines it would be replacing, so range would suffer, and with its supercharger mounted at the back of the engine, one cannot use engine mounted cannons either.

    On the other hand, they could certainly use some things the Allies had earlier, for example VHF radios, IFF in fighters, that appeared about 2 years later than with the Allies; or H2S mapping radar in their bombers.
     
  14. Glider

    Glider Well-Known Member

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    Its a personal view but the problem with the Db605 was that in that last couple of years it relied on GM1 or MW50 to make the Me109 competative. This added weight and complexity for a very temporary gain. The Griffon was able to make those performance gains as a stand alone unit.
    Unlimited high octane fuel.
    Germany did have as you rightly say, high octane fuel but they lacked quantity. This touches on the DB605 which was originally designed for B4 87 Octane fuel the C3 higher octane fuel often being kept for use in the Fw190. Had all their fuel been high octane then in the crucial 1943 period the 109 would have had a better performance which would have helped considerably. It wold also have helped with logistics as their were different marks of engine for different types of fuel, a complication they could have done without.
    Gyro Gun Sights
    Again it was a case of too little too late. I did say gyro gun sights when they could make a difference. Germany produced 33 sights by mid 1944, 750 by the end of the war and how many fighters did they produce? tens of thousands. Its also timing. The first RAF gyro gunsight was operational in 1941, it wasn't great being almost useless against fighters and was replaced by the MkII sight from late 1943 but if the Luftwaffe even had the Mk1 in 1943 against the first 8th Air Force raids, the USAAF losses would have been significantly greater and who knows what would have happened to the restart of the daylight raids in 1944.

    Your other suggestions are good ones and ones I would totally agree with
     
  15. Shortround6

    Shortround6 Well-Known Member

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    Depending on sources the Perseus could have been 100lbs heavier (over 1100lbs) , in any case you still have the extra couple of hundred pounds of "stuff" the dry engine needs to turn it into a runner. You also have the Fact that a Perseus was about 4 in bigger than a Twin Wasp, 15 in or more in diameter than the G-R engine. While take-off and climb improve the increase in top speed or even cruising speed may be marginal. A pair of 14.7 sq ft engines have got to have more drag than a pair of 7.6 sq ft engines. Put that together with a truly dismal view from the cockpit (try getting a side view and moving the top of the cowling up about 8in (200mm) and we can see that this would be a qualified success at best.
     
  16. Tante Ju

    Tante Ju Banned

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    #16 Tante Ju, Jun 6, 2011
    Last edited: Jun 6, 2011
    The Griffon was an engine something like 200 kg heavier than the 605, effectively in the same weight/size/power class as the contemporary DB 603 or Jumo 213. Moreover it wasn't a stand alone unit, for charge cooling (for which MW 50 was used) it required an intercooler, with the associated intercooler radiator system fitted, which added just about as much bulk as say an MW 50 or GM 1 system. So in the end you will end up with a more powerful, but also much heavier engine (and aircraft), and because of greater 'thirst' of the Griffon, greater fuel consumption. Either one accepts shorter range or adds more fuel to compensate, which again adds to take off weight. So its not clear cut if there would overall gain. After all you use another engine to get more performance from aircraft, not just to have more horsepower shown on pamphlets!

    Thing I wonder, why so few Griffons produced? Very few aircraft produced with it. Was it very complex engine? Or different priorities? I would believe RR was strongly required make many for heavy bombers, four engines plus spares each. Perhaps overloaded with orders.

    A couple of things. German aero engines were generally of larger displacement, so they did not need heavy superchargering to produce higher outputs, and a result did not need higher octane fuel to allow this heavy supercharging. Until 1944, they operated at around 1.42 atmospheres, for which 87 octane was sufficient. Sure you could add 100 octane instead, which would allow higher boost pressures, and greater ouputs, but that's just half the story. The engine parts also had to be mechanically strong enough to tolerate that for acceptable times for being suitable for operational service. It was a very significant barrier, much more so than fuel availabilty, for example the Merlin went from about 1000 HP output to about 1700 HP during the war, all on the same 100 octane fuel, but it took some 3 years of engine development to make the engine strong enough, so it can reliably produce it in service, and design additional systems to make that possible (intercoolers etc.)

    It was not due to the lack of fuel, but engineering limitations. As far as the 605 goes, the Daimler engineers had difficult for about 1.5 years to fix the problem with the engine's lubrication system to even allow 1300 HP ouput, and could not reliably use 1475 HP output, though it was perfectly possible on 87 octane. This limited performance, not fuel. BTW there was also a 605, the 605D in 1942 designed for 100 octane, but for the reasons mentioned above, it was very little advantage compared to the parallel developed 87 octane A-version (1550 HP vs 1475). Fuel was not the limitation here, you could have added 1000 octane fuel, still the engine would not take more than 1300 HP, because the lubrication system was faulty, and bearing would burn as a result. In fact many Allied reports pose the question: why do the Germans develop and have fuels with rating of 150 octane if their engines do not make use of it..? When this fixed finnaly (in mid 1943) it was very easy to go up with power, up to 1800 HP with MW 50 and even only 87 octane. Even if 100 octane was used, the MW system was still needed, as it was responsible for charge cooling. Of course this could have been alternatively solved with intercooling, but the same restrictions would apply as in the case of the Griffon alternative. Intercooling system would have also added similiar weight and, unlike MW system, also drag. The Germans considered this inefficient for fighters, but they used intercoolers in their bombers, and some very big fighters like the Ta 152. After all the intercooler radiator is the same size on both fighters and bombers, but its a much smaller percentage of drag on a big bomber, so it doesn't count for much (the extra power does, however!) Similiar story with BMW 801, first version (C) used 87 octane and was good for about 1600 HP. Later D version used 100 (150) octane, and was, in theory, good for 1800 HP, but in practice due to engineering difficulties of airframe and engine other nature it had to be de-rated for lower boost (at which 87 octane fuel would be probably still good enough), until about 1943.

    Do you have perhaps information about the quantity of high octane fuel Germany produced compared to low octane fuel? As far as I understand 109s run on 100 octane in 1944/45. Sometimes also earlier, ie. 100 octane powered versions of 109F. Speaking of that: actually the 87 octane powered 601E (1350HP) was considerably more powerful than the preceeding 100 octane 601N version (1175 HP - planned for 1400, but the engine had trouble sustaining this mechanically)!

    Moreover 109 would need better altitude engines. This was possible on 87 octane, a very good engine, 605AS was made. 100 octane would add more output, if engine mechanically could take it, but only at low altitudes, without better supercharger. Little use for B-17s flying at 8000 meter.. also GM-1 was available for this purpose. Extreme altitude performance, very simple construction. But its more suited for special units for rarer tasks. For 'everyday' use, if this was demanded by tactical circumstance, larger supercharged engine like AS type was more practical solution. Could be mass produced, less trouble with ground maintaince and filling airraft with liquid NO2 from special container trucks. When US Air Force arrived and flew regularly at very high altitude, this become consideration. Until then, not. British and Soviet bombers did not have altitude flying capabilities. No point responding to threat that do not exists!

    Good point about logistics. Though this only effected Fw 190 units. Other units could have been supplied with high grade fuel (and often were), as there was no problem operating an engine designed for low octane fuel, on higher octane fuel. Even bombers operated on 100 octane sometimes (probably due to logisitics), though they did not need it. But it also imposes the question: why would one produce more of more expensive higher octane fuel (since German high octane fuel was the same as low octane fuel, just with more additives), if only a fraction of the units require it? Its economically unsound idea! More work with it, more chemical components needed, greater cost, no advantage...

    I think you'd find the predictor sight development went parallel with the Allies. The Germans begin development in 1935, the Allies in 1939. Both produced a working example by 1941, the Mark I GGS and the EZ 40 respectively. Unlike the GGS however, which had a small aparture, the EZ 40 had a reflex sight like the normal REVI, and was probably more useful in practice. So I think the Germans would have needed more of a replacement of a few heads in the RLM, which decided against standardizing EZ 40 (or any other EZ series, there were a couple to choose from!), rather than an Allied sight of similiar properties and timeframe. The reason however behind rejectment was not all irrational. All predicting sights - Allied or German - were only as accurate or helpful as the guesswork of correct distance to target, if that was inaccurate - and it was, it was guessed by the pilot, and also time consuming to get right, difficult during combat - then sight was actually worse than normal sight, as it gave completely false targeting information. Germans did not like Allied GGS for this reason. Design was considered worse than their own EZ 42. Moving graticule of the G.G.S. could be obscured by the target. German sight also had more accurate predicting firing elements. This was not solved until after the war with radar assisted ranging. Regardless, these sights on both sides came into service at about the same time. German one a couple of months later. War ended anyway. In 1943, nobody had such sight in numbers in aircraft.
     
  17. Glider

    Glider Well-Known Member

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    Before I say anything I must thank you for your posting and the obvious effort that went into it.

    Griffon vs DB605
    I am not going to contest any comments about thirst, I don't know the details but everyone is aware that range always was the Achilles Heal of the Spitfire and I have little doubt that you are correct. The problem I have with the MW50 or GM1 is that once the fuel is used up its dead weight, the Griffon didn't have this limitation, it had recomended boost times for sure, but if push came to shove the pilot could still go beyond those periods. Also it wasn't dead weight on the Griffon it helped at all altitudes at all times, not just the period the boost was available.

    High Octane Fuel
    I wasn't aware of the engineering difficulties that the German designers had going above 1,300hp (maybe I should have said Merlin instead of DB605). If thats the case then the extra octane wouldn't have helped which reduces the importance. However Germany did produce different versions of the DB 605 for both types of fuel, DB 605 ASB(M) / DB 605 ASC(M) for 87 octane and 100 Octane respectively.
    I don't have any details about the volume of each type of fuel that was produced but the attached link shows the aircraft and fuel in service in March 1945. Its notable that the C3 was exclusively for the Fw190 and the B4 for the Me109 and I am certain that the 109 pilots would have preferred the extra performance that came with the fuel.
    Kurfürst - Luftflottenkommando 6, Führungsabteilung I. (Ia Flieg) - Ausrüstung der Jagdverbänden. H.Qu., des 19.3.1945.

    Gyro Sights
    On this we will have to differ. The Allies had thousands of gyro sights in service during WW2 with the first one falling into German hands in 1942 on a P47. I am aware that the Germans considered that their sights were better, but going with the old saying The Best is the Enemy of the Good I refuse to believe that Germany wouldn't have been better off with a Gyro sight in 1943 which would have decimated the USAAF daylight raids. They received serious losses but what if the Gyro sights had been in service even the RAF mark 1, and the accuracy of the fighters had increased even by 25 - 50% can you imagine what would have happened to those bombers?.
    I don't disagree that the EZ 40 was a better sight than the RAF mark 1, but it didn't enter service and what the Luftwaffe needed was something in service.
     
  18. bobbysocks

    bobbysocks Well-Known Member

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    remember when you change anything on an aircraft...especially an engine....if its longer or heavier...you will also change the aircrafts center of gravity. you may change it enough negate some of its better quailities. so to put a big ass engine in it you may need to completely reengineer the ac.
     
  19. Tante Ju

    Tante Ju Banned

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    #19 Tante Ju, Jun 6, 2011
    Last edited: Jun 6, 2011
    Thank you!

    MW or GM liquid was good for 25-30 minutes usage. Overall. One time continous permitted 10 minutes (like Griffon 5 minutes limit - arbitrary. Could be exceeded. Once. Twice. Then risk engine fail on sortie later all sudden. Over infantry trench just machine gunned perhaps. :D One standard fill of tank, ca. 80 liters. Consumed at 150 liters per hour. Fuel consumed ca. 600 liters every hour as per table. So after using MW 50 for half hour you have 100 liter fuel remaining in 109. You go home. Or stay around a little and glide home. :D Need no worry about MW but fuel to get home. Same with Griffon. Consumption of fuel 180-200 gallons per hour.. tank 120 gallon. After half hour at maximum boost, go home or glide home. :D Also MW GM system is not very heavy. Fuel is heavy, roughly 80 kg. Tank is light, its made of light metal. But intercooling system has weight also, similiar overall.

    But IMO its different choice, correct on both sides. British engines were small in displacement, need supercharging. Say make 1000 HP for cruise, 27 liter Merlin will need more supercharging than 35 liter DB. Otherwise cant make 1000 HP.. so intercooler is needed. And good fuel, otherwise it detonates. Big DB engine does not need supercharging, and no charge cooling. Only for maximum power. MW was only used for max. power. Exception two speed DB 605.. it also used MW for combat climb rating. Quasi intercooler. Installing Griffon has problems. Mark VIII Spitfire: 7700 lbs. Mark XIV 8500 lbs.. otherwise same as Mark VIII. So Griffon and Griffon systems add 800 lbs.. engine, big radiators, big propeller to make use of engine power.. same would be to 109.. of course speed would be greater, Mark XIV was 50-70 km/h faster, but not better climber. Probably less difference in 109, need to enlarge radiators (Griffon produce 2600 HP. 600 used by supercharger.. big supercharger indeed! But there's 2000 HP for propeller, but 2600 needs to be cooled.. late DB probably develops 2300 HP, and uses 300 for supercharger.) aksi add intercooler radiator.. add drag, unlike Spitfire, already present. Manouverability probably worse because of weight.. and range... two thirds of Merlin variant. So need to add 50% more fuel, +300 lbs for 109. Also problem with gun. Main gun of 109 cannon in engine.. you can't put it in Griffon (or Merlin): supercharger in way. Was mounted on side of DB, place for cannon in middle of engine.. not on Griffon. Probably have to use wings.. again more weight because you will need two guns for wings for balance.

    Its always very difficult decision for engineers what to use. Many variables. Overall best is choosen. Not neccesarily more powerful with more HP. Looks good in pamphlets. German prefer engines with light weight, more simple, less consumption - more efficient, waste less power on overcoming its own weight and put to good use for actually make fighter fast. For bombers they prefer bigger engines. Less effect on bomber. British prefer high horsepower, like racing engine. Data shows end result is similar. Disadvantage of British engine that its, like race engine, does not make planet very green, as it burns very much fuel. But simply need more tankage.

    Engines ASB and ASC are same. Same as DB and DC. Different designation for same engine using different fuel. A bit complicated buerocracy! :D But could be converted to each other. Simple, by mechanic. Some designated DMO for example. A for A version of engine, S for Special (big) Loader, M for methanol, O for Oktan selector. B or C for fuel ignintion time used. Looked site, already know. This posted for by you is for Fleet 6. Eastern front. Other document on site says B-4 is primarly used on Eastern Front. Probably also means C fuel is Western front primarly. But why, cannot tell.. especially as C fuel boosts for low altitude. Same performance at high altitude, and West - high altitude combat. This only true for 605D engine, in G-10 and K-4, just coming into use, could run 2000 HP from late 1944, then banned, enabled again in March. This need C fuel. Other types like G-14, also major type, doesn't matter of B or C fuel used. Performance is same. Only advantage of C fuel is if MW system works bad - then B fuel is in trouble, as it will detonate without MW. C fuel do not. So C fuel is preferred, but not neccessary.

    EDIT: Another American document says C fuel was 2/3s of German production. No seems shortage. Except shortage of all fuels in 1945 hehe. But not shortage of B or C type fuel. Shortage of both.
    Also document says process of building B and C fuel. They are same. C fuel is made of B fuel, but has extra chemical process involved, typically DHD type. I am no chemist but it seems they could make any ratio of B fuel to C fuel. All C fuel if wanted, even, from same stock. Remember German fuel was almost all synthetic. Pure chemical process, from coal. Can make any chemical desired, but making high octane fuel this way is more expansive, as more chemical process is involved; of course whole syntetical process is more expensive, than drilling oil, but neccessary for Germans. Smart move before war to invest into these plants by Goering. Also listings of C fuel find in crashed G-10, G-14, G-6, G-8. Obviously on West - English report.

    Agree. Some sight is better than no sight! But problem was not with sight (ready) it was with heads. Need to replace heads making decision, not sight. :)
    You mentioned GGS has produced in great numbers. I believe it was produced from late 1943, or perhaps start 1944. German sight came couple of months later. At this period, probably not so important, neither had it ready in 1943. In 1944, it was not very neccessary for Germans, they did not need sight even, just shoot in the air, hit something Allied. Of course joking.. but trouble was not sight. Still, would be usueful, but would couple of months be difference? Do you have numbers of use? Or produced? Aircraft it was used in? I believe American first.
     
  20. Glider

    Glider Well-Known Member

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    Thanks again for the information. Re the production of the M2 Gyro Sight in 1943 production started at a new factory built just produce these sights.
    UK Production was approx 7,500 sights and production was running at 1,100 a month at the end of the war. It was also in production in the US as the K14 for the USAAF and K18 for the USN what they produced I have no idea, about but its safe to say it would have been significant numbers. What is interesting is that some were fitted to bomber command rear turrets.

    As for who got them first this is a memory so treat it with care, the RAF had them first which was only to be expected in the US the USN were most keen and too the lead but some 8th Airforce aircraft were fitted with RAF sights only semi officially.
     
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