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I think the basic Vulture concept was sound, they just never had the time to work out the kinks and optimize the design. So yes, a X-24 with Merlin cylinders and blocks could have been viable.One does wonder what a 24 cylinder engine using Merlin cylinders would do though
If I am not mistaken, the last 3 major piston engine projects taken on by RR were sleeve valve engines - ie the Crecy, Pennine, and Eagle. They obviously thought the sleeve-valve was worth pursuing. The output powers - actually achieved and projected - speak for themselves.
Also for the same approximate displacement, the 2817 in3 Eagle put out about the same power at max cruise as the max war-rime power (without ADI) of the 2805 in3 R-2800, while weighing about 66% more but having a smaller cross section (10.7 ft2 vs 15.2 ft2 - note that this does not count the cross section for the coolant radiator for the Eagle, or the oil coolers for either engine).
Sometimes it feels people succumb to nostalgia wrt sleeve valves (not pointing fingers at you here, just as a general observation). Poppet valves are these boring clattering things even my lawn mower has, surely these exotic high end aero engines must use sleeves because they are inherently superior!As has been pointed out in other threads, the poppet valve matured a lot during the inter-war and war years, possibly making the development of the sleeve valve unnecessary. On the other hand, a large part of the development problem with the sleeve valve was the manufacturing of the sleeves themselves - in terms of the process development and of quality control. Today there would be no inherent problem manufacturing the sleeves or the fiddly bits like the sleeve valve gear train.
As to how much the sleeve valve design contributed to the power I do not know - by the end of the war it was probably a wash vs poppet valves.
A major factor in the lack of market share post-war was the increased complexity and cost associated with the sleeve valve and its gear train. For a given displacement the sleeve valve seemed to cost about 1/3 more per BHP relative to the poppet valve engine, though how much of this was due to economy of scale and/or the difference in competence of the makers is a question.
And yes, that plane would have been smaller than the Typhoon. And sure, have Napier design and build that engine, if the ministry is concerned about avoiding a RR monopoly.
Please, do tell.Ironically, Rolls-Royce were very occupied in keeping Napier out of the market and it took a champion in the MOD to get the go ahead for the Sabre, IIRC.
Please, do tell.
Thank you.George Purvis Bulman?, I think I hear, at 2:50 to about 3:50.
This is Flight Dojo I got this from.
Agreed, no source is perfect and you and other members with your superior knowledge are more likely to spot errors.Unfortunately, the video mixes up the 1 HP/cu in hi-per mantra adored by the US Army with what was going on in the UK. It also over-sells the Rapier and Dagger by a good deal.
Engine weight was/is an important consideration for the aircraft designers. An extra 1500 lbs was a big difference for the aircraft of ww2, that will demand bigger wing, bigger undercarriage, stronger fuselage - the things that push up the weight and drag. More fuel needed, bigger tail, heavier prop - again pushing up the weight, and with it the size of wing, so again we have more drag. Do we get a fighter that is better than the late-marque P-47, P-51 or (Sea) Fury?
Corsair does not need a 3500-4000 lb engine to make close to 470 mph - the -5 was supposed to do 469 mph (347 kt). Super Corsair was with 1-stage S/C, it will not be as good at high altitudes as the -4, let alone -5.Whether any of the single-engine airframes potentially powered by the Eagle would surpass the earlier airframes, who knows.
Would the F2G Corsair benefit from the R-4360 being replaced by an Eagle?
In the F2G Corsair (13,350 lbs TOGW clean) Eagle installation you would have a single(?) 4- or 5-blade prop, with an approximate total installation weight increase of ~500-600 lbs (including engine coolant system) with 3500 BHP, vs the R-4360 as actually installed with 3000 BHP. A 500 BHP increase with ~15% less engine installation drag and excellent Meredith effect equals ? Is the F2G/Eagle gain in Vmax of ~40 mph (~470 mph vs 430 mph) worth it?
The A1D Skyraider (~14,000 lbs TOGW clean) used the R-3350 engine (2500 BHP without ADI). The AM-1 Mauler (~20,000 lbs TOGW clean) used the R-4360 (3000 BHP without ADI). The Eagle (3500 BHP without ADI) was originally planned for the Wyvern (~20,000 lbs TOGW clean) and was installed in a few very early production TF Mk 1.
Check out the Hornet, very fast and nimble, with better power/weight ratio than it should've been possible with the Eagle. There is also a redundancy of having a second engine.The P-82 Twin Mustang(~20,800 lbs TOGW clean) used either 2x Merlin (~3700 BHP total without ADI) or 2x Allison (~3500 BHP total without ADI). 1x Eagle w/counter-rotating props or 2x Merlin/Allison engine installation weights would be about the same overall. A single-engine/single-fuselage airframe with the Eagle should have significantly less drag than the twin-engine/twin-fuselage P-82 Twin Mustang, and probably less overall weight.
Agreed but they could haul more weight and airframe volume. This translating into more available load appropriate to whatever the assigned tasks. At this point it therefore increased their advantage against short ranged jets. Also they were in the early stages of further development and would likely have produced even more power in due course. In the case of passenger and transport aeroplanes the ICE was still the norm until the 1960s and big ICE engines still had a potential role. For the Mk1 Bristol Brabazon they went to the trouble of combining two Centaurus engines each driving one of the two contra rotating propellers at IIRC 3,500bhp the set. Yes they wanted to then go on to turboprops but the very big ICE engines in the 5,000bhp class would be a simpler alternative. Yes I know the Brabazon was not successful but it worked fine and it's fault was in marketing not engineering. On speed, with the right aerodynamics the Russians got over 900km/hr out of the propellor driven Tu95 so there is no reason not to expect it to be possible with the big ICEs.Problem that all of the very late, very heavy and very powerful piston engines were having was propelling something beyond 450-470 mph, while the less powerful and widely available engine were able to do the same.
What kind of load vs. combat-radius we're talking about?Agreed but they could haul more weight and airframe volume. This translating into more available load appropriate to whatever the assigned tasks. At this point it therefore increased their advantage against short ranged jets. Also they were in the early stages of further development and would likely have produced even more power in due course.
In the case of passenger and transport aeroplanes the ICE was still the norm until the 1960s and big ICE engines still had a potential role. For the Mk1 Bristol Brabazon they went to the trouble of combining two Centaurus engines each driving one of the two contra rotating propellers at IIRC 3,500bhp the set. Yes they wanted to then go on to turboprops but the very big ICE engines in the 5,000bhp class would be a simpler alternative. Yes I know the Brabazon was not successful but it worked fine and it's fault was in marketing not engineering.
On speed, with the right aerodynamics the Russians got over 900km/hr out of the propellor driven Tu95 so there is no reason not to expect it to be possible with the big ICEs.
Just use sixteen 3750hp enginesThe 15000 HP engines on the Tu-95 were ICE, but not piston engine. A 15000 HP piston engine would've been a sight to see.
I don't want to divert the thread to a Brabazon one but it had the ability to change from the high price low number passenger marketing model to a large number low cost one for key long distance routes on the model of the transatlantic Icelandair CL44 service in the 1960s. As Freddy Laker put it, it is a greater achievement to fly people at half the price than in half the time. It was simply a market that was not considered. The airframe was up to the job, with a suitable interior and limited baggage. Pack in the peasants into cattle class. As an airframe it worked fine. The Mk2 would have been even better and there are simpler ways to provide 14,000bhp plus than 8 engines, 8 propellers, 4 gearboxes with with 144 cylinders and, IIRC, 288 spark plugs. However, a separate thread would be a more suitable one to discuss that matter. Working full time 24 hours the time to change all spark plugs will be 3 days with one man permanently on the job. One begins to see why the turbines seemed attractive solutions.What kind of load vs. combat-radius we're talking about?
Very big piston engines of 5000 HP were very complicated alternative to anything, not simpler alternative.
Lockheed didn't get the memo that 8x 18 cyl engines are required. People that green-lit the Brabazon should've gotten the comfy & cozy post in the Falklands, counting penguins or whatnot.
The 15000 HP engines on the Tu-95 were ICE, but not piston engine. A 15000 HP piston engine would've been a sight to see.
As long as you can produce engines in the same ballpark in terms of power/weight, the bigger engine should be able to result in a faster aircraft, as the frontal area grows slower than the size (=power) of the engine, and various equipment like cockpit and pilot, guns, etc. become a smaller portion of the whole weight. Though it's of course hard to compare, as many of these late prop planes were developed in an era where it was clear that jets were the future for pure fighters emphasizing speed, and thus they had to emphasize other attributes like being able to operate from carriers, or ground attack in general rather than a pure fighter role.Problem that all of the very late, very heavy and very powerful piston engines were having was propelling something beyond 450-470 mph, while the less powerful and widely available engine were able to do the same.
My money would be on liquid cooled radials. Take 9 banks of Griffon cylinders and connect them to a common crankshaft, and you have a 56 cylinder engine making around 9000 hp. Put two of these back-to-back driving contra-rotating props. Or cheat a bit, and have push-pull nacelles with one engine driving a tractor propeller ahead of the wing and the other engine driving a pushed prop behind the wing. But yes, maintenance guys are going to hate it. Or be extremely happy about the job security!The 15000 HP engines on the Tu-95 were ICE, but not piston engine. A 15000 HP piston engine would've been a sight to see.
For some reasons all of the multi cylinder engines of over 24 cylinders seemed to run into difficulties. They sounded real good in the sales brochures but............Take 9 banks of Griffon cylinders and connect them to a common crankshaft, and you have a 56 cylinder engine making around 9000 hp.