11 / 22 cylinders radials

[msxyz]

Hello gentlemen,

I'm looking for every possible information regarding the few 11/22 cylinder radial engines ever produced. High quality pictures or drawings would be appreciated.

Engines that I know of:

WW1 period

Clerget 11 - Rare 11 cyl. rotary engine. At least one preserved specimen in museum

Siemens Halske SH.III - 11 cyl. rotary engine with counter rotating crankshaft. Several specimens surviving. Great deal of material and info available

WW2 period

Wright R-4090 - Prototype. 22 cyl. Only images scanned from books available
Mitsubishi Ha-50 - 22 cyl. A complete, but damaged, specimen is displayed at the Narita airport. High quality pics would be welcome
Hitachi Ha-51 - Prototype. 22 cyl. Only images scanned from books available

Did I miss anything? Thanks!

 

[wuzak]

Bristol Orion - 22 cylinder version of the Centaurus, though it looks like it was never completed.

A projected enlarged capacity version of the Centaurus was designed by Roy Fedden, cylinders were produced for this engine but it was never built. Known as the Bristol Orion (a name used previously for a variant of the Jupiter engine, and later re-used for a turboprop one) this development was also a two-row, 18 cylinder sleeve valve engine with the displacement increased to 4,142 cubic inches (67.9 l).[

Bristol Centaurus - Wikipedia, the free encyclopedia

 

[Oreo]

That would be interesting. Is there any practical limit to how many cylinders a radial engine bank can have? I think I've seen pictures of five and three cylinder engines, and seems like somewhere I heard about a 6-cylinder radial, which of course would be "odd" since it was even. Not sure how the firing order would work on that-- maybe as if it were two separate 3-cylinders?

 

[wuzak]

That would be interesting. Is there any practical limit to how many cylinders a radial engine bank can have? I think I've seen pictures of five and three cylinder engines, and seems like somewhere I heard about a 6-cylinder radial, which of course would be "odd" since it was even. Not sure how the firing order would work on that-- maybe as if it were two separate 3-cylinders?

The Jumo 222 was a 4 row, 6 bank radial.

The firing order would work as for any radial, but you could have two cylinders firing at once, I suppose.

Size is the limiting factor for how many cylinders a radial can have. Give the same cylinder size, adding cylinders will eventually reach a point where no more can be put in without having to increase the diameter. The Bristol Hercules and Centaurus have much the same diameters (the Centaurus has a longer stroke). The Wright R-3350 has a slightly larger diameter than the R-2600, even though teh cylinder dimensions are the same.

 

[msxyz]

Are there any high quality photos of the Ha-50 preserved at the Narita airport?
I only found a handful and all poor quality / resolution

It seems that, of all the 22 cylinders projects, this was the most promising. Basically Mitsubishi took the basic and sound Kasei engine (14 cylinders) and scaled it up to 18 (Ha-102) and 22 cylinders with little effort. Diameter was around 1450mm so it was pretty compact despite the number of pots.

As for why engineers stopped at 9 cylinders per bank, the answer is probably diameter (which translates in a bigger front area) and wasted space between the cylinders head. A two row approach allow more cylinders to be fitted in a smaller area while leaving exposed the hottest part of the engine (the heads) to airflow.

 

[Shortround6]

That would be interesting. Is there any practical limit to how many cylinders a radial engine bank can have? I think I've seen pictures of five and three cylinder engines, and seems like somewhere I heard about a 6-cylinder radial, which of course would be "odd" since it was even. Not sure how the firing order would work on that-- maybe as if it were two separate 3-cylinders?

Curtiss built a 6 cylinder radial in the 20s/early 30s. it was actually a two row engine. two rows of 3 cylinders.

 

[Oreo]

Curtiss built a 6 cylinder radial in the 20s/early 30s. it was actually a two row engine. two rows of 3 cylinders.

That would actually work with no problems. The one I remember but can't place was 6 cylinders all in one row.

 

[msxyz]

That would actually work with no problems. The one I remember but can't place was 6 cylinders all in one row.

Anzani 6-cylinder - Wikipedia, the free encyclopedia

 

[robwkamm]

Here is a picture of a 6 cylinder 2 stroke radial from my collection. Unknown maker. looks like a homebuilt kit.

 

[msxyz]

From my understanding, two stroke radial engines can be either with an odd or even number of cylinders. The only problem is scavenging which cannot be done through crankcase, in a radial. Forced induction scavenging and cross-head scavenging can be used instead.

Four stroke radials engines need an odd number of cylinder to have an even (pun intended!) distribution of the power strokes.

 

[robwkamm]

this one has a big impeller fan under the front cover and it has mechancal fuel injection . 2 plug heads and injection through the center of the head.

 

[Piper106]

"Bristol Orion - 22 cylinder version of the Centaurus, though it looks like it was never completed."

As far as I have seen, the Orion was a 18 cylinder engine with bigger cylinders (6.25" bore x 7.50" stroke) than the Centaurus (5.75" bore x 7.00" stroke).

 

[Oreo]

Yep, it can be done.

 

[wuzak]

"Bristol Orion - 22 cylinder version of the Centaurus, though it looks like it was never completed."

As far as I have seen, the Orion was a 18 cylinder engine with bigger cylinders (6.25" bore x 7.50" stroke) than the Centaurus (5.75" bore x 7.00" stroke).

Sorry - you are correct. It even says so in the snippet I quoted.

 

[Aurum]

Ha-50 ...
It seems that, of all the 22 cylinders projects, this was the most promising. Basically Mitsubishi took the basic and sound Kasei engine (14 cylinders) and scaled it up to 18 (Ha-102) and 22 cylinders with little effort. Diameter was around 1450mm so it was pretty compact despite the number of pots.

I guess that Hitachi Ha-51 was not less promising then it. Hitachi was not so busy by other engine development as Mitsibishi was so it seems Ha-51 could be quickly completed refined. The other thing is that Sakae type cyls were really too small to be economically worthy.

In all cases Hitachi might start Ha-51 project somewhen in 1939-40 so to have engine perfectly refined in 1942-43.

By the way as far as I understand both Ha-50 Ha-51 are Army designation so as they do not fit unified designation rules. According to unified designation they must be Ha-52 Ha-55 correspondingly because 2 codes of 150/170 cyl. size 5 codes 130/150 cyl. size. At the end of the war Japanese introduced used unified designation, but these late engines are coded only in Army system! Why?

 

[johnbr]

Here are two cutaway of the Br-18cyl and Br 28cyl.

 

[kmccutcheon]

I'm looking for every possible information regarding the few 11/22 cylinder radial engines ever produced. High quality pictures or drawings would be appreciated.

...

Wright R-4090 - Prototype. 22 cyl. Only images scanned from books available

Please see C-W R-4090

 

[swampyankee]

From my understanding, two stroke radial engines can be either with an odd or even number of cylinders. The only problem is scavenging which cannot be done through crankcase, in a radial. Forced induction scavenging and cross-head scavenging can be used instead.

Four stroke radials engines need an odd number of cylinder to have an even (pun intended!) distribution of the power strokes.

iirc, only small 2-stroke engines use crankcase scavenging. The big ones -- like the ones made by MAN-B&W or Sulzer -- don't. Crankcase scavenging doesn't provide enough air flow.

 

[msxyz]

After a few months of research I obtained a few, high def photos of the restoration project of a Siemens SH3. Pure engine pr0n!!! Not a WW2 engine but still interesting in its own right as in this engine both the case and the crank rotates in opposite direction (to balance the gyroscopic forces) and, unlike many other rotaries of the era, it had a proper throttle carburettor, necessary because it was optimized for high altitude performance.

 

[AMCKen]

Pics / info here
narita1