Radial vs. V Engines

[Krusty]

2 crankshafts? Seems kinda redundant, overly complicated, and I can see why it was unreliable.

Heck, even today we're still having gearbox problems on 2 powerplants sharing the same shaft (the Osprey development comes to mind)

[Hazzer]

 The problems with the Napier Sabre were gradually ironed out in service with the Typhoon.

 The Typhoon suffered not only engine failures,but structural failures mainly due to tail flutter,this continued even after tail strengthening,although to a lesser extent,as did carbon monoxide leaking into the cockpit from the Engine bay a problem the much improved Tempest shared.

 Not using the oxygen mask at any altitude in either model could be - and on more than one occasion was -  fatal.

[BaldEagl]

Basicly, its been an arguement for years which one was better, and pretty intresting which contry pick which.
Japanese=mainly radial (D4Y and Ki-61 are exceptions)
British=mainly inline
U.S.A.A.F.=mix of inline and radial, but only radials for bombers
U.S.N.=mainly radial
German=mixed
Russia=mixed

I just watched a video I have at home a week or two ago about the FW190.  The only reason they used radials in the 190's was because all the in-line production was committed to the 109 series.  It wasn't by choice. 

In fact, Kurt Tank tried to streamline the cowl by elongating it and reducing the radius toward the front but it restricted airflow to the engine too much and was removed.

It turns out the extra HP from the radial more than compensated for it's lack of streamlining.

I suspect available manufacturers and production capability played a role in many of these choices moreso than design choice, although use of radials by the USN was definately design choice.

[2bighorn]

2 crankshafts? Seems kinda redundant, overly complicated, and I can see why it was unreliable.

Reliability problems were mainly due to production rather than design. Whilst the H design is more complicated than V configuration, it was the only way (at that time) to get that kind of volumetric efficiency and keep the size compact enough for fighter plane use.

[Saxman]

Pony,

Severity of engine torque wasn't dependent on the engine configuration. A high-powered inline engine could put out just as much torque as an equivalent radial. The difference is that radial engines typically put out higher horsepower to begin with.

[2bighorn]

The difference is that radial engines typically put out higher horsepower to begin with.

That was true up to early '30s and only for power/weight ratio.

The main advantage of radials was simplicity which almost always translated into reliability.

[Krusty]

The most powerful late war engines of the allies were radials. Look at the P-47M/N and the F8F, and other similar designs.

Overall the radial, because it was simple, because it was larger, could pump out more power. The flaw/drawback is that you had to design an airframe around this giant dead weight in the nose. Sometimes the extra horsepower overcame the extra drag, sometimes it wasn't worth it.

[2bighorn]

The most powerful late war engines of the allies were radials. Look at the P-47M/N and the F8F, and other similar designs.

They were about equal in terms of specific power and also power to weight ratios (Griffon vs R-2800)

Napier Sabre had considerable advantage in specific power over R-2800 and being about equal in power to weight ratio.

[Krusty]

But that's where reliability comes in I guess... Sabre: highly unreliable, R2800: totally reliable.

[SectorNine50]

2 crankshafts? Seems kinda redundant, overly complicated, and I can see why it was unreliable.

Heck, even today we're still having gearbox problems on 2 powerplants sharing the same shaft (the Osprey development comes to mind)

Really?  The Osprey has a drive shaft going through the wings to link the engines?

Is this for RPM matching in case one fails?  I could see how in that aircraft losing one engine would be catastrophic, you'd lose every bit of control.  If it had at least one engine rotating both props, it could at least make a controlled (kinda...) landing.

[Widewing]

Inline... Duh...

I knew that... lol

You were right the first time. A 2.0 liter Honda four cylinder engine is an "inline". A V12 is a V type.

There were V12s, radials of various cylinder counts and rows from 1 thru 4. There were H-24 cylinder engines, V24s, V8s and even 6 cylinder diesels. Irrespective of the type, using the terminology of "inline" for any V engine is technically incorrect. So, you were right initially.


My regards,

Widewing

[sNiPeR]

I just watched a video I have at home a week or two ago about the FW190.  The only reason they used radials in the 190's was because all the in-line production was committed to the 109 series.  It wasn't by choice. 

the Dora 190 had a Junkers Jumo 213A1 inline engine,hence the longer nose.

[Bronk]

To bad thiswas too late for the war.

http://en.wikipedia.org/wiki/Pratt_%26_Whitney_R-4360

[Ponyace]

Pony,

Severity of engine torque wasn't dependent on the engine configuration. A high-powered inline engine could put out just as much torque as an equivalent radial. The difference is that radial engines typically put out higher horsepower to begin with.

Your right, sax. looking back, I remember hearing about inline planes that did have bad torque characteristics. I believe the 109 had a bad turn trait to the right if I remember correctly.

[BaldEagl]

the Dora 190 had a Junkers Jumo 213A1 inline engine,hence the longer nose.

You are correct.  I forgot that tidbit.