Re-engined planes

[tomo pauk]

I'll be home the day after tomorrow, so just a little patience

 

[Markus]

The defender of free world - P-40.
The most criticized part of plane was that engine power was not seen sufficient for such tough plane, in ETO mostly. So here it is: P-40 with R-2600.

Talk about lost opportunities.

 

[Colin1]

I'll be home the day after tomorrow, so just a little patience

I need it by Friday
don't you know there's a war on?

 

[tomo pauk]

Always those demands from Air ministry

Here is an up-engined Mossie, the engines are Sabres for almost 4500 HP in 1943. Radiators removed to end of nacelle to cater for upped frontal weights. The new fuel cells in place of where once were radiators.

 

[zoomar]

If Fairey can do it, so can Junkers: Stuka with 2 engines. BMW or Bramo, retractable U/C, much easier instalation of tank-busting cannon(s), while it could still hurl a big bomb if no heavy cannon is present.
2nd pic lacks wing engine to show 37mm cannon mounting. An all-around ground attack plane, with perhaps 1-2 30mm cannons, more up forward, or in wing roots, would of course enable the big bomb all the time. Stern barbete (not shown here) would be nice to have.

Now that is an incredibly cool looking airplane!!

 

[tomo pauk]

Talk about lost opportunities.

Strangely enough, although R-2600 was the most powerful (reliable available that is) aircraft engine 'till R-2800* come to play, it never served in a fighter aircraft. It was way more powerful than contemporary DB-601/605/603, Jumos, Merlins, BMW 801 prior 1945. Not to mention Soviet Japanese designs.

*Napier Sabre was contender with bugs solved in mid/late 1943

 

[Shortround6]

It had two things against it as a fighter engine.

1. it's diameter, it was as big as an R-3350 which didn't do much for streamlining in the early days, bigger than an R-2800.

2. Wright never seemed to get a good high altitude supercharger. While take-off and low altitude power seemed to be fine even the 2 speed supercharged engines had critical (full throttle) altitudes of around 11,000-14,000ft which for western use was a bit on the low side. Not much better than an Allison. Combine that with the fact that there was no WER rating or that military power at 11,000-14,000ft was several hundred HP below the take-off rating and it just didn't offer the performance fighter designers were looking for. Great at getting heavy twin engined planes off the ground though.

 

[tomo pauk]

The über-Mosquito - with two turbo-charged R-2800
Turbos are at the end of nacelle.The late-1945 variant would've boast with 5600 HP on board.

 

[zoomar]

Another underdog - He-112.
Here is how those Romanians coul've used M-88 engine from captured Su-2 (1000-1200 HP, depending on who is talking) to make it go faster then Yak-1 stuff.

Well, here's what the Hungarians did try, the Weiss-Manfred WM-23, a He-112 variant with a Gnome-Rhone radial:

 

[tomo pauk]

It had two things against it as a fighter engine.

1. it's diameter, it was as big as an R-3350 which didn't do much for streamlining in the early days, bigger than an R-2800.

2. Wright never seemed to get a good high altitude supercharger. While take-off and low altitude power seemed to be fine even the 2 speed supercharged engines had critical (full throttle) altitudes of around 11,000-14,000ft which for western use was a bit on the low side. Not much better than an Allison. Combine that with the fact that there was no WER rating or that military power at 11,000-14,000ft was several hundred HP below the take-off rating and it just didn't offer the performance fighter designers were looking for. Great at getting heavy twin engined planes off the ground though.

1: The diameter was only 5% greater than of Twin Wasps, the wide-spread fighter engine, says Wiki. The diameter was 4% greater than of R-2800, so not a great issue. If we look at A-20 B-25 cowlings, those were surely well streamlined.

2. Wright was never tasked with such thing (hi-alt hi-performance). R-2800 (mech-supercharged) also took time to develop a supercharger set for 20kft +.

 

[tomo pauk]

Well, here's what the Hungarians did try, the Weiss-Manfred WM-23, a He-112 variant with a Gnome-Rhone radial:

Wow, at 1st glance I thought it was F-4U
Neat looking plane.

 

[Shortround6]

1: The diameter was only 5% greater than of Twin Wasps, the wide-spread fighter engine, says Wiki. The diameter was 4% greater than of R-2800, so not a great issue. If we look at A-20 B-25 cowlings, those were surely well streamlined.

Please do the math. Twin Wasp is 48.1in in diameter, R-2600 is 54-55in in diameter. 6in is more than 5% of 48in.

Frontal areas are given as 12.6 sq.ft for the twin wasp, 16.1 sq ft for the R-2600 and 14.8 sq ft for the 52.2 in dia R-2800.

At 105.6hp/sq ft for the the R-2600 vs 135.1 hp/sq ft for the R-2800 isn't to hard to figure out why the fighter designers skipped the R-2600. HP is 1700 for the R-2600 and 2000 for the R-2800.

The cowlings on the A-20 and B-25 were well streamlined but nowhere near as good as the cowlings on the FW 190 and the LA-5 through 9 series than used fan cooling. A feature that helped keep down the overall size of the cowlings on those planes.

2. Wright was never tasked with such thing. R-2800 (mech-supercharged) also took time to develop a supercharger set for 20kft +.

That is true but it sure doesn't change the fact that the Wright engine never had one while the P&W R-2800 was in production with such a supercharger by mid/late 1942.

The Wright engine was a very good engine that powered a lot of very good and very useful aircraft. It just wasn't a good choice for a fighter engine given what else was available.

Allison engines being good for 1400-1500hp at altitudes of 5,000ft or so when running at WEP in late 1942 or early 1943.

 

[tomo pauk]

Yep, you're right about the difference vs. Twin Wasp - my bad.

I'm not pitting R-2600 vs. R-2800 in performance category - no point in that.
But if we talk about availability date, R-2600 beats the 2800. That was my point all the way. Planes powered by 2600 were in combat 2 years before the ones with 2800 - not a bad thing for WW2 needs.

As for cowlings - esp. the one at A-20 looks really neat to me. I guess fan-cowling was no rocket science to prevent installation in an US fighter.

Allison engines being good for 1400-1500hp at altitudes of 5,000ft or so when running at WEP in late 1942 or early 1943.

Two quirks there:
-5kft makes pretty low altitude, 1.7 km perhaps.
-It's WEP rating for Allison. I doubt that WEP was out of capability of Wright to develop it by 1942 if brass asked for it in time German tanks overran Poland or France.

 

[Shortround6]

. Planes powered by 2600 were in combat 2 years before the ones with 2800 - not a bad thing for WW2 needs.

What planes powered by R-2600s were in combat in the summer of 1940?

As for cowlings - esp. the one at A-20 looks really neat to me. I guess fan-cowling was no rocket science to prevent installation in an US fighter.

The fan cowlings weren't rocket science but nobody used them until the FW 190 showed the way. Early attempts at streamline cowlings on the P-42 and P-48/66 didn't work out so well.

Two quirks there:
-5kft makes pretty low altitude, 1.7 km perhaps.
-It's WEP rating for Allison. I doubt that WEP was out of capability of Wright to develop it by 1942 if brass asked for it in time German tanks overran Poland or France.

Liquied cooled engines worked better at WEP. You had to overload the cooling system which took a few minutes compared to overheating the aircooled engine.
A GR2600-A5A engine from a 1941 book was credited at 1600hp for take off at 2400rpm. 1600hp/2400rpm at 1500ft low blower military power and 1400hp/2400rpm/11,500ft high blower military power.
Radial engines didn't take to over revving as well as V-12s did either.
WEP was usually obtained at below the rated altitude of the engine by fulling opening the throttle rather than restricting it's opening in order to limit power and save the engine.

Quirks are that a standard P-40E could develop close to 1500hp at low altitude for a couple of minutes instead of the 1150hp take off rating which evens things up a bit compared to a R-2600 which while rated for take-off at 1600-1700hp wasn't rated any higher. And at altitude the P-40E was still good for 1150hp at 11,000ft compared to the R-2600s 1400-1500hp at 11,000-14,000ft.
The R-2600 does have more power but not as much as a comparison of the take-off ratings suggests.

If you can find a rating for WEP for a R-2600 I would be interesting in seeing it.

 

[Waynos]

Hmm, stupid idea coming.........pure fantasy of course...........Jet powered versions of the allied heavies, akin to the post war testbeds, but all-jet for 1945 deployment (4/6 Derwents/Goblins?)

High altitude turretless Lancaster for 500mph at 40,000ft?

 

[Colin1]

High altitude turretless Lancaster for 500mph at 40,000ft?

In 1945
could we hit anything from 40,000ft?

 

[Waynos]

The ground

 

[Colin1]

The ground

Now
if we could just get the enemy to build his factories on the ground...

 

[Colin1]

If you can find a rating for WEP for an R-2600 I would be interesting in seeing it

I doubt you'll find one, the R-2600 was never fitted to fighters

 

[tomo pauk]

What planes powered by R-2600s were in combat in the summer of 1940?

Okay, than it's 20 months vs. 24 as I've claimed. Still plenty of time - much less divides Fw-190 from Battle of Britain, or BMW-801 TS-series from 1944 combined bombing offensive, F4-U from Midway etc.

The fan cowlings weren't rocket science but nobody used them until the FW 190 showed the way. Early attempts at streamline cowlings on the P-42 and P-48/66 didn't work out so well.

Fw-190 badly needed the fan to provide useful level of reliability for it's engine - while still not beating R-2600 in power/availability/reliability combo for 3/4s of it's operational use (3 years that is).

Liquied cooled engines worked better at WEP. You had to overload the cooling system which took a few minutes compared to overheating the aircooled engine.

Again, perhaps in theory. The Russian Ash-82FN had 'forsage' option to bolster the power output for short period of time - WEP in Russian that is.

A GR2600-A5A engine from a 1941 book was credited at 1600hp for take off at 2400rpm. 1600hp/2400rpm at 1500ft low blower military power and 1400hp/2400rpm/11,500ft high blower military power.

In other words, it took 2 years, plus WEP for Allison to almost equals the performance of R-2600 of 1940/41? I rest my case

Radial engines didn't take to over revving as well as V-12s did either.
WEP was usually obtained at below the rated altitude of the engine by fulling opening the throttle rather than restricting it's opening in order to limit power and save the engine.

Okay - again it theory.

Quirks are that a standard P-40E could develop close to 1500hp at low altitude for a couple of minutes instead of the 1150hp take off rating which evens things up a bit compared to a R-2600 which while rated for take-off at 1600-1700hp wasn't rated any higher. And at altitude the P-40E was still good for 1150hp at 11,000ft compared to the R-2600s 1400-1500hp at 11,000-14,000ft.
The R-2600 does have more power but not as much as a comparison of the take-off ratings suggests.

That's still 250-350 HP more, 2 years before.
Clear advantage in my eyes - I bet Germans would've ritually sacrifice ms. Eva Braun for availability of a reliable 1500 HP engine for Bf-109s in time of BoB. USA was the only country that had that option available, and they skipped it.

If you can find a rating for WEP for a R-2600 I would be interesting in seeing it.

Colin covered that

Actually, I've spent a lot of time searching for power curves of piston engines, but those are as rare as hen's teeth. I'd love to lay my hands on any of it