MOST UNDERRATED AIRCRAFT OF WWII? (1 Viewer)

[J.A.W.]

No SR6, I am not the one missing the point, the sad fact about British politico-industrial leadership
& organisation being so inept in many instances - is a different subject from engine design merits.

& here is a service trial of a sleeve-valve powered machine from late `41:
http://www.wwiiaircraftperformance.org/typhoon/Typhoon_AFDU_Tactical_Trials.pdf

Performance figures well in advance of any other contemporary service test machine.

& despite the well documented shambles that accompanied the Typhoon in 1941-43,
a comparison with the F4U shows which of that pair reached its design goals 1st.

P pbehn , here is Roy Fedden's list of sleeve-valve merits:
http://www.flightglobal.com/pdfarchive/view/1941/1941 - 2830.html

 

[pbehn]

No SR6, I am not the one missing the point, the sad fact about British politico-industrial leadership
& organisation being so inept in many instances - is a different subject from engine design merits.

& here is a service trial of a sleeve-valve powered machine from late `41:
http://www.wwiiaircraftperformance.org/typhoon/Typhoon_AFDU_Tactical_Trials.pdf

Performance figures well in advance of any other contemporary service test machine.

& despite the well documented shambles that accompanied the Typhoon in 1941-43,
a comparison with the F4U shows which of that pair reached its design goals 1st.

P pbehn , here is Roy Fedden's list of sleeve-valve merits: http://www.flightarchive.com/pdfarchive/view/1941/1941 - 2830.html

J.A.W. you are not a fool so why act like one, the sleeve valve had merits and de merits, the aviation industry decided the de merits were more important. Peak horsepower is one issue, reliability and serviceability is another.

 

[J.A.W.]

Yeah the Warwick was an orphan, the last of Britain's dud attempt at big medium bombers,
& underpowered when flying with R-2800 bomber mills, so most def' a waste of a brace of Sabres,
'cept maybe - for a thrill-ride - Vmax = Vne.. woo hoo...

http://www.flightglobal.com/pdfarchive/view/1946/1946%20-%201439.html

 

[J.A.W.]

J.A.W. you are not a fool so why act like one, the sleeve valve had merits and de merits, the aviation industry decided the de merits were more important. Peak horsepower is one issue, reliability and serviceability is another.

Incorrect yet again, ben.. as the linked evidence - should you choose to avail yourself of it - shows..

 

[swampyankee]

To increase performance from two row 18 cylinder, radial air cooled engines or V12s was not easy. Based on a maximum bore and stroke of 6inch the radial has the advantage because of 18cylinders but water cooling a radial is almost impossible.

By 1944 Rolls Royce could no more come up with a ready made air cooled radial design any more than Wright could produce a water cooled H or V format engine.

Salmson produced -- not prototyped -- water-cooled radials. For a slightly larger engine, so did Nordberg and Zvezda. In the realm of prototypes, Lycoming R-7755 and Curtiss-Wright R-2160.

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@ J.A.W.,

One should also not conflate unit cost with design excellence; the Model T was an extremely well-designed product that used some advanced materials (and some not so advanced) to optimize utility, e.g., a high-alloy steel was used for parts to improve service life. This has gotten quite far afield from the original topic of the thread; the argument of the superiority (or not) of sleeve valves and Napier engines may be worth its own thread, but it's quite irrelevant to the question of which aircraft were under-rated.

 

[pbehn]

Incorrect yet again, ben.. as the linked evidence - should you choose to avail yourself of it - shows..

I read them, it is incredible how the links you post repeatedly point to reliability issues in almost every paragraph.

 

[J.A.W.]

@ SY, I don't think so, many a time - engine-airframe are twofer deal..

Take the proposed Spitfire replacement - the Tornado, without the Vulture, it was a dead-duck.
Unlike the Manchester which by accepting 2 Merlins for each Vulture, successfully morphed into the Lancaster..

& a Model A Ford, for all its value-for-$ practicality,
it wasn't going to whip an SSK Mercedes-Benz over 24hrs @ Le Mans..

 

[J.A.W.]

I read them, it is incredible how the links you post repeatedly point to reliability issues in almost every paragraph.

"Incredible"?
Really? - I'd reckon reliability issues were a fairly self-evidently obvious concern for users of aero-engines..

 

[pbehn]

@ SY, I don't think so, many a time - engine-airframe are twofer deal..

Take the proposed Spitfire replacement - the Tornado, without the Vulture, it was a dead-duck.
unlike the Manchester which by accepting 2 Merlins for each Vulture, successfully morphed into the Lancaster..

& a Model A Ford, for all its value-for-$ practicality, wasn't going to whip an SSK Mercedes-Benz over 24hrs @ Le Mans..

The Typhoon/Tornado were supposed to be the spitfire/hurricane replacement as a high altitude inteceptor, after many years and three engines in many guises they managed it at low altitude only

 

[J.A.W.]

Which just happened to be where the most useful 'trade' could be found, for ADGB in that period, too..

 

[pbehn]

Which just happened to be where the most useful 'trade' could be found, for ADGB in that period, too..

That "period" being 1944 is one of your choosing, it was supposed to be sorted in 1941/42, but it needed a new engine, wings, fuselage, canopy and tail. The Typhoon was required as a top class all altitude fighter in 1942 but it lapsed into a ground attack plane with a radiator in 1944, the Tempest, when introduced in 1944 it was in a world of jets and rockets.

 

[KiwiBiggles]

I read them, it is incredible how the links you post repeatedly point to reliability issues in almost every paragraph.

Are you really implying that the Hercules, which was in widespread service for much of the war, was significantly less reliable than its contemporaries?

 

[pbehn]

Are you really implying that the Hercules, which was in widespread service for much of the war, was significantly less reliable than its contemporaries?

No, I was referring to all the links posted about sleeve valve engines by J.A.W. the Hercules seems to take a back seat behind the stellar performance of the Sabre and Centaurus.

 

[KiwiBiggles]

No, I was referring to all the links posted about sleeve valve engines by J.A.W. the Hercules seems to take a back seat behind the stellar performance of the Sabre and Centaurus.

So the mainstream use of sleeve valves during the war proved normally reliable, but the urgent development of the next generation of engine was problematical. Sounds pretty standard for engine development worldwide.

 

[Shortround6]

I do like the car comparisons though. Like the US was incapable of build powerful cars. Picking one of the cheapest US cars of the time and comparing it Blower Bentleys and Mercedes SSKs to try to prove a point about aircraft engines is ludicrous.
Yes the US 2 valve radials were cheaper but not the 10 to 1 ratio (or more) that these cars were. and comparing a 4.5liter supercharged engine to a 3.3 liter unsupercharged car sure doesn't tell you anything new, let alone bringing in the 7 liter supercharged SSK.
Maybe we should bring in the 1928 Stutz? The one that lead Le Mons for over q/w the race before the Gear box broke (and lets remember that the Bentleys often failed to finish 100% of their starters)

We are getting a bit far afield.
The Sleeve valve engines were developed, as I have said before, into high powered, reliable and long lasting engines. It is just that they didn't offer that much of an improvement over the poppet valve engines of the same time. The millions of pounds invested in the sleeve valve never really paid off despite the gee whiz numbers posted by the last of the engines.

 

[pbehn]

So the mainstream use of sleeve valves during the war proved normally reliable, but the urgent development of the next generation of engine was problematical. Sounds pretty standard for engine development worldwide.

Not really because the Merlin replaced it in the area that it was supposed to be replaced, high altitude interceptor. The Napier Sabre sleeve valve was only marginally reliable in service, when you have to heat engines and "run them up" every few hours you need two maintenance crews, time between overhauls was 25 hrs at times. Engines with similar swept volume went on to power the worlds airliners, the Napier Sabre was retired ASAP and not sold to anyone. You could say that the Centaurus was more successful, but how many engine variants did the Typhoon Tempest have in the course of the war?

 

[J.A.W.]

No..
Viz: 1942/43, the 'Focke-Wulf scourge' where FW 190s indulged in 'tip & run' JaBo attacks,
even to the extent of 'laying on' - a mass daylight raid on London itself in Jan `43..

Spitfires could not catch these fast intruders when they were running hard for home,
but Typhoons could, & did..

Same with sneaky Do 217 recce & mine-layer intruders, they were fast enough at low level to
often evade Spitfire interception attempts, but Typhoons could run them down..

As for V1s, Sabre powered Hawkers garnered the 'lions share' of fighter victories there too,
preventing 800+ of the Nazi vengeance cruise-missiles from crashing down on Londoners..

 

[KiwiBiggles]

The Sleeve valve engines were developed, as I have said before, into high powered, reliable and long lasting engines. It is just that they didn't offer that much of an improvement over the poppet valve engines of the same time. The millions of pounds invested in the sleeve valve never really paid off despite the gee whiz numbers posted by the last of the engines.

Retrospectroscope, much? Poppet valves for high-performance engines were saved by the development of high octane fuels. At the time when sleeve valves were being developed - the Hercules started development in 1936, I think - high octane fuels didn't exist. Sleeve valves were a pretty good way to get high performance from 87 octane fuel.

 

[J.A.W.]

Not really because the Merlin replaced it in the area that it was supposed to be replaced, high altitude interceptor. The Napier Sabre sleeve valve was only marginally reliable in service, when you have to heat engines and "run them up" every few hours you need two maintenance crews, time between overhauls was 25 hrs at times. Engines with similar swept volume went on to power the worlds airliners, the Napier Sabre was retired ASAP and not sold to anyone. You could say that the Centaurus was more successful, but how many engine variants did the Typhoon Tempest have in the course of the war?

Still wrong, ben..

Read the AFDU Tactical Trial.. the Spit V was whipped.. ( & the FW 190 proved it).
& "marginally reliable" - seriously - where do you get this stuff from?

The RAF had standards, & if the Sabre was as awful as you purport, it would've been cancelled, like the Vuture..
& certainly not kept in hard-duty service 'til 1955..

Here's an exercise for you ben, compare the two Kiwi fighter squadrons operational in Blighty, No's 485 & 486,
485 was Spitfire equipped & 486 went Hurricane-Typhoon-Tempest, guess which - had the 'results on the board'..

 

[J.A.W.]

Retrospectroscope, much? Poppet valves for high-performance engines were saved by the development of high octane fuels. At the time when sleeve valves were being developed - the Hercules started development in 1936, I think - high octane fuels didn't exist. Sleeve valves were a pretty good way to get high performance from 87 octane fuel.

Indeed, Wilkinson notes that the fuel spec for the final Sabre - rated at 3,500hp for take off, was regular 100/130..