I can tell that the DB 608 is missing from that thorough list. It was a development of the DB 601 optimized for high altitudes, with 37l displacement and producing 1650Hp.
I`ve never seen that DB 624 photo. Great!!
J A W- that is food for thought. Comparisons of aircraft performance around the BoB by both sides was biased by their doctrines ... they were pretty closely matched leapfrogging each other as new marks were introduced. When I have a moment I'll revisit the specific power vs year curves of the Merlin and DB's. David Isby's Decisive Duel book certainly explains the operational viewpoints in Chapter 18 but we should continue to focus on the power to fly. I'll post a revised curve if necessary when I've studied and considered the results.
Thanks but the illustrated nacelle for the DB609 that I asked about looks more like it is intended for a twin-engine aicraft, hanging under a wing. If anything, it looks very similar to a He219 nacelle to my eye but it might just be the annular radiator that does that.
DB-612, a cylinder head engine, because it did not use "mushroom" valves but rotating discs with ports that in their turn coincided with the exhaust and intake ports of the cylinder head.
outer gear teeth that connected with all the discs, turning at the same time in its position of correct draft. A butt without the disks and another with them installed. This system can be a variant of the famous Burt-McCollum-style sliding tube engines (without valves
:-X The DE-607 was a similar diesel in architecture and size at "603" for 1750 hp. It was abandoned and did not go into production.This was a four-stroke diesel engine, whose initial development was at the behest of Lufthansa, later however its usefulness to long-range military aircraft was also realised. The first engine was running in 1939, however the V3 and V4 (1940/41) were only experimental engines. Dimensions were similar to the DB 603. Take-off power was 1100 KW (1,500 HP) and with development should have reached 1285 KW (1750 HP) at 1500 rpm. If this had been successful then with a weight of 860 kg a power to weight ratio of 0,49 kg/HP would have resulted. Sources differ as to when it was cancelled, the earliest states 1941 the latest October 1942.DB 630, a 36 cylinder Double W engine with a capacity of 89 litres and output in the 4,000 HP class (2,940 KW). Dr. Berger calculated the optimal cylinder arrangement angles should be 40Â° + 40Â° + 100Â° and it was designed to use only one crankshaft. Development was abandoned in April 1943.
the DVL`s sliding discs (drehscheiben) were a clever and simpler method when compared with the Burt McCollum system, itself ingenius.Had they time enough to develop it would be functional.
Stay aware because there are another edition of Bernard & Graefe`s "Flugmotoren & Strahltreibwerke" on the run.
How did the rotating disc valves perform in testing? As for the comparison with sleeve valves, I think these rotary valves are inferior due to the fact that the combustion chamber design is pretty much the same for rotary and poppet valves whereas the sleeve valve system allows optimum combustion chamber design. Sleeve valves coupled with direct injection (direct injection allows better cylinder scavenging that carbs/singe point injection) would have been a truly great design.
Earlier it was mentioned how DB chose to increase compression ratio while keepiong boopst low. That was an utterly stupic decision. While raising compression ratio improves fuel consumption a bit and power too, it raises maximum cylinder pressure (factor determining how strong the engine construction has to be plus how detonation-resistant fuel one needs) while BMEP curve rises only gradually. On the other hand, keeping CR low and using high boost as the means of increasing power, cylinder max. pressure rises much less in comparison with BMEP (power) rise while allowing the power increase with lower octane fuel. Remember that Allison reduced the CR with the ultimate G-series V-1710.
I have been reading old Shell Aviation News magazines. A certain Sir Harry Ricardo was one of the authors writing for it and he has a most interesting graph showing the effect of CR on BMEP and max. peak pressure. Needs opnly a quick look to make one wonder what the hell was DB thinking. BTW, the DB 605A was prone to burned pistons and for considerable time the use of emergency rating was banned due to this. And burned pistons indicate high peak pressure and temperature within cylinders.