Curtiss XP-37/YP-37

[wuzak]

And as for the 5 stubs....you learn something new everyday !

http://s150.photobucket.com/user/feropete/media/Mosquito/Exhaustsinboard.jpg.html

[tomo pauk]

What engines proved to be a waste?

Late 1930s: Continental IV-1430 (yep, inverted V), it's opposed version, the O-1430; Lycoming O-1230 and it's 24 cylinder sybling, the H-2470. Pratt & Whitney X-1800, though the last two were also a bit too late to compete with 1st V-1710s.

Did the USN, RAF, or Luftwaffe have this?

Probably not, but then for the relatively simple Hurricanes and Bf 109s there was no need as it was the case with US turboed aircraft.

[wuzak]

3rd, there was no 'system integrator' person/institution for a complex thing of combining a new engine, new type of supercharging and new installation.

Did the USN, RAF, or Luftwaffe have this?

The integration of systems in US aircraft was, at that time, the airframe manufacturers. That includes building exhausts to turbos, and ejector exhausts too.

In the UK the engine manufacturers did more of this. Rolls-Royce spent some time getting the ejector exhausts working, and there were several iterations of these. They also designed quick change engine modules, such as the Merlin power egg, which made the Lancaster possible.

Certainly BMW made quick engine change modules for their 801 radial. Daimler-Benz and Junkers developed radiator installations to go with their engines (ie the annular radiators), and maybe even the QEC modules. I think the 801 module was interchangeable with the Jumo 211 module, as several aircraft could be specified with either.

[KJ_Lesnick]

tomo pauk

Late 1930s: Continental IV-1430 (yep, inverted V), it's opposed version, the O-1430; Lycoming O-1230 and it's 24 cylinder sybling, the H-2470. Pratt & Whitney X-1800, though the last two were also a bit too late to compete with 1st V-1710s.

• As I understand it, the UK built several sleeve-valved engines
  
• Regarding the IV-1430 and O-1430: Why did they develop two engines around the same purpose?
  
• As for the Lycoming O-1230, was it better than the Continental O-1430?
  

Were there any inlines other than the V-1710 or V-3420 in the US that would have been considered suitable?

Probably not, but then for the relatively simple Hurricanes and Bf 109s there was no need as it was the case with US turboed aircraft.

Okay


Wuzak

The integration of systems in US aircraft was, at that time, the airframe manufacturers. That includes building exhausts to turbos, and ejector exhausts too.

In the UK the engine manufacturers did more of this. Rolls-Royce spent some time getting the ejector exhausts working, and there were several iterations of these.

Why the difference if I may ask?

They also designed quick change engine modules, such as the Merlin power egg, which made the Lancaster possible.

That's a smart idea -- modular is often a good idea.

Certainly BMW made quick engine change modules for their 801 radial. Daimler-Benz and Junkers developed radiator installations to go with their engines (ie the annular radiators), and maybe even the QEC modules. I think the 801 module was interchangeable with the Jumo 211 module, as several aircraft could be specified with either.

Was this common all over Europe?

[tomo pauk]

As I understand it, the UK built several sleeve-valved engines

Yes.

Regarding the IV-1430 and O-1430: Why did they develop two engines around the same purpose?

Probably as an insurance, in case one ends up as a lemon. Didn't work out, though - neither worked when needed, if at all.
Actually - the O-1430 was supposed to fit flat in the bomber's wings (to drive the prop via extension shaft), that IV-1430 could not being the V-12.

As for the Lycoming O-1230, was it better than the Continental O-1430?

Don't know, the less said above the two the better? If you want to read more about those (and plenty of other things related), there is a downloadable book by Robert Schlaifer and S.D. Heron, called 'Development of aircraft engines', written post war.

Were there any inlines other than the V-1710 or V-3420 in the US that would have been considered suitable?

No, unless the Chrysler really develops their V-2200, the V-16 engine.

[KJ_Lesnick]

tomo pauk

Probably as an insurance, in case one ends up as a lemon.

If you do build two designs as a hedge, aren't you supposed to cancel one design when one appears better?

[tomo pauk]

Both failed.

[KJ_Lesnick]

tomo pauk

Both failed.

But doesn't one usually fail before another?

[tomo pauk]

For those two engines, it really didn't matter. By the time they were barely working, USA was producing vast quantities of V-12 and radial engines that really worked while making anywhere between 1000 and 2000 HP, with even more powerful stuff of 'classic' layout in the pipeline.

[wuzak]

The integration of systems in US aircraft was, at that time, the airframe manufacturers. That includes building exhausts to turbos, and ejector exhausts too.

In the UK the engine manufacturers did more of this. Rolls-Royce spent some time getting the ejector exhausts working, and there were several iterations of these.

Why the difference if I may ask?

No idea.

But it may have something to do with the procurement system in place in the US, where items such as engines and turbochargers were government furnished equipment (GFE). The government would buy these items and then give them to the airframe manufacturers to install.

Certainly BMW made quick engine change modules for their 801 radial. Daimler-Benz and Junkers developed radiator installations to go with their engines (ie the annular radiators), and maybe even the QEC modules. I think the 801 module was interchangeable with the Jumo 211 module, as several aircraft could be specified with either.

Was this common all over Europe?

Not sure.

The US also had some QEC modules, usually designed by the airframe manufacturer.

The V-3420 installation in the XB-39, for example, was a QEC designed by Fischer.

[wuzak]

tomo pauk

Both failed.

But doesn't one usually fail before another?

How do you define failure?

The IV-1430 started life as an O-1230 (IIRC), before being upsized and then changed to an inverted Vee, once the planners realised that the drag savings for burying an engine in the wing were not there.

The IV-1430 had more single cylinder development hours than the Merlin had development hours before it went into production.

Continental was entirely reliant on government funding, not putting any of their own money in. Each change or new design stage had to go through approval and an ordering process before it could proceed.

I think the IV-1430 was abandoned in 1944/45.

Not sure if the Lycoming O-1230 actually failed. Lycoming put their own money into it, but soon realised it was too small to be useful. So they doubled it up to make the H-2470.

The H-2470 powered a couple of prototypes, but did not receive any orders.

I think the H-2470 also suffered from having many configurations offered before the base engine was sorted. 1 stage, 2 stage, 2 speed prop drives, etc.

[tomo pauk]

Not being used in a military aircraft gives us the clue.

I'll again strongly suggest downloading and reading the Schlaifer's book, along with 'America's hundred thousand' and 'Vee's for victory' for anyone intersted in (not just US) ww2 fighters and their engines tecnicalities.

[KJ_Lesnick]

wuzak

How do you define failure?

As a general rule if a designer was building two designs: One would often see one of the following

• One design is clearly performing better than the other
  
• One design is showing more development problems than the other
  

Eventually one would realize which way the wind blows and kill the under-performer and develop the good design with full resources?

The IV-1430 started life as an O-1230 (IIRC)

I thought there was an O-1230 developed by another company?

Continental was entirely reliant on government funding, not putting any of their own money in.

Good business model LOL!

Each change or new design stage had to go through approval and an ordering process before it could proceed.

Probably slows development

Not sure if the Lycoming O-1230 actually failed. Lycoming put their own money into it, but soon realised it was too small to be useful.

The horsepower output appeared to be similar to the V-1710 at first: I'm surprised it's development didn't continue even if the H-2470 continued.

The H-2470 powered a couple of prototypes, but did not receive any orders.

Evidently there were reliability issues...

I think the H-2470 also suffered from having many configurations offered before the base engine was sorted. 1 stage, 2 stage, 2 speed prop drives, etc.

Prop drives?  Are you sure you don't mean supercharger drives?

[wuzak]

How do you define failure?

As a general rule if a designer was building two designs: One would often see one of the following

• One design is clearly performing better than the other
  
• One design is showing more development problems than the other
  

Eventually one would realize which way the wind blows and kill the under-performer and develop the good design with full resources?

One might mature more quickly while the other may have more potential. Do you keep the one you are going to get sooner or the one that will be more useful?

In any case, the IV-1430 was being developed at the behest of the USAAC, while the O-1230 was largely a private venture. In that case it is hard for the government to kill one, while not wanting to kill the other.

The IV-1430 started life as an O-1230 (IIRC)

I thought there was an O-1230 developed by another company?

The O-1230 was developed by Lycoming, but the IV-1430 started life (on paper) as an O-1230, before becoming an O-1430 and then the IV-1430.

The Continental and Lycoming engines were based on the "Hyper" cylinder developed at the Engineering Division of the USAAC in the late 1920s. No coincidence that they had the same capacity (initially).

These engines (and the Chrysler IV-2220) shared common features - such as separate cylinder designs, 2 OHV per cylinder in a hemispherical combustion chamber.

I think the H-2470 also suffered from having many configurations offered before the base engine was sorted. 1 stage, 2 stage, 2 speed prop drives, etc.

Prop drives?  Are you sure you don't mean supercharger drives?

No, two speed prop drive. Also specified as an option for the Wright R-2160 Tornado.

One speed for take-off and landing, another for cruising flight.

[KJ_Lesnick]

wuzak

In any case, the IV-1430 was being developed at the behest of the USAAC, while the O-1230 was largely a private venture. In that case it is hard for the government to kill one, while not wanting to kill the other.

The O-1230 however did work though correct?

The O-1230 was developed by Lycoming, but the IV-1430 started life (on paper) as an O-1230, before becoming an O-1430 and then the IV-1430.

Okay, I gotcha.  Why did they go from O-1430 to IV-1430?  And why did they feel the O-1430 had enough potential to consider justification?

The Continental and Lycoming engines were based on the "Hyper" cylinder developed at the Engineering Division of the USAAC in the late 1920s. No coincidence that they had the same capacity (initially).

The goal of the hyper-project was over 1 hp per cubic inch of cylinder based around the idea of a sleeve-valved engine?  Out of curiosity, why did they focus on HP/Cubic Inch instead of HP/Pound?

These engines (and the Chrysler IV-2220) shared common features

Yeah, the IV-2220 was the first hemi: Even I know that.

Regardless, how many of these types of engines were built... it seems like such a huge number of engines

Allison

• V-3420: First proposed in 1934, first run in 1937, first suitable for use in 1942-1943?
  

.
Continental

• IV-1430: Begun in 1932, became IV-1430 in 1934?
  
• O-1430: Begun in 1938
  
• XH-2860: Designed, but I'm unsure if it was built
  

.
Lycoming

• O-1230: Begun in 1932 (progressed faster than the IV-1430 by 1935)
  
• H-2470
  

.
Pratt & Whitney

• X-1800 (H-2240): Developed in the 1938-1940 period; eventually enlarged to 2597.7 (H-2600)
  
• XH-3130: Developed in the late 1930's; eventually enlarged into the XH-3730 and cancelled in 1940 in favor of the Wasp-Major (I think that was a good choice)
  

.
Wright

• R-2160 Tornado: Proposed in 1940, first used in 1944
  

As far as I know...

No, two speed prop drive.

To permit more efficiency for cruise and more power for takeoff?