R-1830 in a fighter plane: any ways to concieve a performer?

[tomo pauk]

The Twin Wasp was one of the most popular engines in the ww2. It was, in different versions, powering fighters, bombers, transports etc. For good reasons, it was left aside 'by' the new fighters with better performing power plants.
So was there any chance to make a fighter around the R-1830, that would perform admirably vs. current fighter opposition? The requirements do not include the 'Berlin and back' combat range, nor the firepower ammo capacity of the P-47 - ie. a more 'European-ish' size weight is preferred. Both single engined and twin engined fighters' proposals belong in this thread.

 

[Shortround6]

I think we have been over this before.

Short answer.... NO......

The Swedes with the FFVS J22 came the closest to what you are looking for. It does depend on what you are willing to give up.

See: Home

There is a lot of detail there and a lot of comparisons.

 

[riacrato]

Looking at the Zero with its comparably powered engine... I guess with careful streamlining and weight reduction (at what costs?) you could do a bit better than the P-36, about A6M level... 550-570km/h? There's only so much you can do with a 1000-1200hp'ish radial.

 

[msxyz]

Meet the FFVS 22

FFVS 22 - Wikipedia, the free encyclopedia

Keep in mind that, in service use, Swedish air force had to limit its power output to 1050 hp because they couldn't get aviation gasoline with high octane ratings. With the 1200-1350 hp achievable using different fuels, the J22 could have performed even better.

Edit: ninja'ed. I'm too slow to write replies! Another aircraft with a similar engine and similar projected performance is the Nakajima ki-44 Ib : 1250 hp engine of 1.26 m of diameter, 1950 kg empty, 580 km/h @ 3700 m, time to 6000m a little less than 6 minutes. All with a single speed supercharger.

 

[Shortround6]

You weren't going to get more than 1200hp out of an R-1830 without some major changes to the engine, at least not for very long. There were some 1350 R-1830s made but they show up rather late in the war and use some new components (Heads and cylinders?) developed with/from similar parts from the "C" series R-2800s.
Better cooling was often needed to take advantage of the new fuels.


The early two speed engines were good for 1200hp take off and 4900ft and 1050hp at 13,100 at 2700rpm on 100 octane fuel. They went about 1495lbs.
The Late two speed engines were good for 1350hp take off and 2000ft and 1100hp at 13,750 at 2800rpm on 100/130 octane fuel. They went about 1573lbs.

 

[davebender]

I think the Fw-187 would perform well powered by a pair of 1,200 hp R1830 engines. However it would be easier to increase DB601 engine production then to copy the R1830.

 

[Shortround6]

Please note that the power output of a late model R-1830 on 100/130 isn't much different than a Merlin III on 100/??? fuel and 12lbs boost low level as used in the BoB. Merlin is about 200lbs lighter which goes a ways in offsetting the radiator.

 

[Vincenzo]

What happend if put a R-1830 in a Macchi C.200? if not gain too much drag and weight maybe a good fighter (not a top). Over 1/3 more power at TO...

 

[GregP]

Not a bad idea Vincenzo. I wish we had one we could try it on ... but I wouold have to restore it to stock confoguration so we could have an original unit first! Maybe if we had two?

 

[Shortround6]

It may have helped. The P&W was about 200lbs heavier but only about 25-30mm bigger in diameter. Power at altitude was a bit closer. 1050hp at 4000 meters for the P&W with 2 speed supercharger. The Fiat was good for 840hp at 3800 meters. DB 601Aa was good for 1100ps at 3700 meters 5 minute rating and 1050PS at 4100 meters 30min rating?

It would have filled in part the gap between the MC 200 and MC 202 but not closed it completely.

 

[msxyz]

What happend if put a R-1830 in a Macchi C.200? if not gain too much drag and weight maybe a good fighter (not a top). Over 1/3 more power at TO...

Wasn't the A.74 loosely based on P&W Twin Wasp design? I seem to remember that FIAT acquired a license and then it designed an engine with similar features but that could be readily manufactured within Italy current industrial capacity and materials, hence the big difference in power (200HP even taking into account the use of 87 octane aviation gasoline that restricts the Twin Wasp to about 1050 HP).

Another Italian radial engine plane that could have benefited is the Reggiane Re.2000 The engine was a straight copy of the Gnome Rhone 14K, manufactured by Piaggio, that always suffered from overheating problems. It was a better plane that the G.50 and MC.200 but it was never mated to a reliable engine.

 

[Vincenzo]

As you writed A.74 is a PW derivative, AFAIK is not clear if from R-1535 (twin wasp jr) or the R-1830 (twin wasp).
i'm agree on Re.2000.
data from wiki (sorry)
R-1830-S1C-G weight 1250lbs diameter 1220mm lenght 1500mm
R-1535-SB4-G weight 1087lbs diameter 1121mm lenght 1353mm
A.74 weight 1300lbs diameter 1200mm lenght 1045mm
14K weight 1190lbs diameter 1296mm lenght 1480mm

 

[Shortround6]

I am afraid Wiki is incorrect on the weight of the R-1830-S1C-G. The weights given in one company record are 1428lbs, 1433lbs and 1403 lbs depending the wither the reduction gear was 3:2, 16:9 or 3:2.

Same document shows a R-1535-SB4-G at 1124lbs.

A compete listing of P&W aircraft engines (including many models that were never manufactured) can be found at the AEHS website

Reference

Scroll down to "Pratt Whitney Reciprocating Engines" and pick a model.

 

[Shortround6]

Duplicate

 

[muscogeemike]

I believe the CAC Boomerang use this engine and was, while not a world beater, considered successful.

 

[Shortround6]

It was a successful ground strafer, army co-operation aircraft, tactical recon? but at MOST may have had 2 air to air combats depending on source, it may have had none. I leave that to our Australian members/experts.

The Wiki entry: CAC Boomerang - Wikipedia, the free encyclopedia

A useful aircraft but it's success as a fighter is highly doubtful.

 

[tomo pauk]

Could it be that the best bet is sticking two turboed R-1830s on a fighter, like it was done with the Grumman XP-50 (and no, I don't blieve the speed of 420 mph for the XP-40, listed by many)?

 

[Shortround6]

It could be. Without the turbo the R-1830 has some real problems as an altitude engine. Even the 2 stage version wasn't all that hot.

For the "common" 2 speed single stage it offered 40hp less 650ft lower than the Allison -33 used in the P-40B&C in Military power.

The 2 stage engine offered 1000hp at 19,000ft. While better than the Allison that isn't really saying much.

The last "hurrah" for the two stage engine was the SSC7-G used in a P-40 airframe as a test mule. They did get it up to 379mph? in late 1942, altitude unknown.

1200hp at 2700rpm at sea level.

Military power
1200hp/2700rpm/2700ft
1150hp/2700rpm/9700ft
1100hp/2700rpm/17,800ft

Normal power (max continuous)
1100hp/2550rpm/3500ft
1050hp/2550rpm/11000ft
1000hp/2550rpm/19,000ft

All power/altitudes may be without RAM.
Compare to 1942 Merlins or 1942 DB engines.

BTW the XP-50 used R-1820s so using R-1830s may cut the drag a bit.

 

[ShVAK]

Two single stage engines, wrapped by as little fuselage as possible would be the winning ticket to clear 400 mph in a R-1830 powered fighter. Basically think Westland Whirlwind but with lighter armament (two 20mm H-S instead of four or two .30 cal/two .50cal). Such a fighter would have great speed for an early war fighter and probably decent maneuverability but suck in terms of range or performance above 20,000 feet--almost exactly like the Whirlwind.

 

[tomo pauk]

Oh, one of my favorite could-have-beens, the Whirlwind with the R-1830s
The range would be easily increased by installing the additional fuel tanks in space previously used by radiators (twice as much fuel possible?), while at 20000 ft it would be something like 2 x 950 HP vs. 2 x 700 HP for historical Whirly. 3 cannons, or 5 HMGs? The weight would be increased, though, and so will be the drag.

[about turboed R-1830 in a twin in order to make a performer]
It could be. Without the turbo the R-1830 has some real problems as an altitude engine. Even the 2 stage version wasn't all that hot.

For the "common" 2 speed single stage it offered 40hp less 650ft lower than the Allison -33 used in the P-40B&C in Military power.

The 2 stage engine offered 1000hp at 19,000ft. While better than the Allison that isn't really saying much.

The last "hurrah" for the two stage engine was the SSC7-G used in a P-40 airframe as a test mule. They did get it up to 379mph? in late 1942, altitude unknown.

1200hp at 2700rpm at sea level.

Military power
1200hp/2700rpm/2700ft
1150hp/2700rpm/9700ft
1100hp/2700rpm/17,800ft

Normal power (max continuous)
1100hp/2550rpm/3500ft
1050hp/2550rpm/11000ft
1000hp/2550rpm/19,000ft
All power/altitudes may be without RAM.

Thanks for the data. I'll just comment about the bolded part: the airframe used did have shortcoming, to forestall an even greater speed increase - draggy wings. It would be interesting to see what the 2 stager would be making with thinner wings, or laminar flow ones? Or, sticking it onto a smaller lighter airframe, like that of the VG-33, or CW-21, or Yak-1/3?

Compare to 1942 Merlins or 1942 DB engines.

It was easy to make a performer with sleek powerful engines, quirk is to make a performer with the bulky not that powerful engine

BTW the XP-50 used R-1820s so using R-1830s may cut the drag a bit.

Agreed