Small displacement V-12s

[Admiral Beez]

I was looking at the DH Albatross and found it remarkable that this was powered by four relatively tiny 18.3 L de Havilland Gipsy Twelve engines, that combined were about equal to the displacement of a single P&W R-4360. The rooting for the cooling ducts is interesting to see too.

What do we think of the small displacement V-12 aero engines of the WW2 era? In the 18-22 L range we see the Sagitta I-MR, Isotta Gamma and of course the RR Kestrel and Peregrine. Some are tiny, like the 12 L As410 and 12.7 L Ranger V-770. This last engine powered the poorly conceived Curtiss SO3C Seamew.

 

[Shortround6]

What's to think?

They were small engines that weren't really going to compete with the big engines.
They were heavier and more expensive that radials of equivalent power.
For many of their makers they seemed to offer a way to use existing parts to get into a higher power market area.

Most were 12 cylinder adaptations of six cylinder engines.
The Walter Sagitta used 12 cylinders from the Walter Major 6-I engine, which were the same cylinders as the Walter Major 4-I engine (118mm x 140mm)
Walter also had a line of engines using 105mm x 115mm cylinders, a four, a six and V-12 ( 728 cu in 11.95 liter)

There seems to have been more than a bit of cross pollination or licensing going on.
The Gypsy Major used 118mm X 140mm cylinders. as did the Gypsy 6 and the Gypsy 12
The Gypsy Minor used 102mm X 115mm cylinders.
The Cirrus Major used 120mm X 140mm cylinders. but they didn't make an engine with more than 4 cylinders.

Renault used 120mm X 140mm cylinders in combinations of four, six and twelve cylinders (Cauldron 714 among others)
Argus used 105mm X 115mm cylinders in the 410 V-12 but 120mm X 140mm cylinders in the air cooled V-8s. (Fi 156 Storch)
Hirth Used 105mm x 115mm cylinders on their line of Four, Six, eight and 12 cylinder engines.

The Isotta Gamma used the same cylinders as the Isotta Beta 6 cylinder (125mm X 130mm)

The Ranger 12 used the same cylinders as one of the early Ranger sixes. The Ranger 6 had started out at 370 cu in, then 390 cu in(actual 386) then 410 c u in and finally 440 cu in.
The V-12 used 102mm x 130mm cylinders.

Gypsy engines were also licensed buy Alfa in Italy and Regnier in France but they didn't make 12s. Other countries may have licensed it.
Potez made a 17.6 liter flat 12 of 510 hp for take off.

 

[wuzak]

Talking of small displacement engines of many cylinders (ie > 12), look at the Napier Rapier and Dagger.

The Rapier was 8.8L for 16 cylinders and the Dagger 16.8L for 24 cylinders.

 

[tomo pauk]

Shorten the stroke of Kestrel and Peregrine and those are also under 20L.
Jumo 210 series gotten to 700 PS on 87 oct fuel.

 

[Admiral Beez]

The Rapier was 8.8L for 16 cylinders...

That is a very small displacement for such a high number of square (bore=stroke) pistons. At 550cc per cylinder, Just think of all the precision-made tiny parts whirling around at high rpm.

The H-layout may make things a little easier, as it's essentially two 8 cylinder vertically opposed engines joined at the crank. Though a 8.8L V16 or V12 might be equally complicated, IDK.

 

[Admiral Beez]

Shorten the stroke of Kestrel and Peregrine and those are also under 20L.
Jumo 210 series gotten to 700 PS on 87 oct fuel.

I agree. I changed the title before I saw your post to include anything we collectively consider small, rather than an arbitrary 20L cut off.