Liquid cooled aero engine with <12 cylinders?

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From post #4 in that thread

Shortround6 said:
There are/were several physical limits to cylinder size and to get the required power they usually needed 12 cylinders. The Mikulin AM-35 series used about the biggest liquid cooled cylinders in a liquid cooled engine. If you had tried a V-8 using the same size cylinders you would have had an 1880 cu in engine which fits in with the others but some of those physical limits meant it didn't run much over 2000rpm which would rather limit it's power compared to the 1650-2300 cu in V-12s that ran at 2400-3000rpm.
A V-8 of the same displacement is shorter and lighter than a V-12. However the bigger cylinders tend to limit rpm and breathing (although supercharging helps overcome that)
Click to expand...

There were no high powered V-8s and no V-10s (the firing order is a bit of a problem) in WW II.
 
Orenda was not trying to build a really high powered engine.

They were trying to make a "cheaper" engine to compete with the P & W PT-6 turbo prop, which had basically killed off any piston engine over 400hp.

Orenda used high rpm (4400) and turbo charging to get power. But it also had the advantage of decades of advancement in materials/heat treatment, lubrication, knowledge of airflow and so on. A lot of these was used to get the overhaul life up to a standard that might be competitive rather than push the performance envelop.

Please note that according to wiki the engine offered 600hp for take off and 500hp continuous for 748lbs dry weight, weight of liquid cooling system was ????

1941 P&W R-985 9 cylinder radial gave 450hp for take off and 400hp max continuous for 668lbs, Wright R-975 Whirlwind was almost the same weight for the same power.
The P & W R-1340 Wasp weighed 930lbs for 600hp take off, 550hp max continuous at 8,000ft and 400hp cruising at 10,600ft.

These were the engines the Orenda was supposed to replace on old bush planes and agricultural aircraft. They were also going after the PT-6 market on business aircraft.

Nobody wanted liquid cooled engines in most commercial (or private) aircraft. It was one more system that needed maintenance or could go wrong. Please note that the inline fours (and sixes) that were air cooled use low octane fuel and very rarely superchargers before WW II.

The Ranger 6 came in four variations at one point. one used 65 octane, one used 73 octane, one used 80 octane and the most powerful used 87 octane. Liquid cooling not needed.

The Germans used inverted air cooled V-8s (using the cylinders for four cylinder engines) but they were in the 200-300hp catagory.
Small liquid cooled engines were usually converted/adapted car engines.
 
pbehn said:
did you read the link you posted?
Click to expand...

Did you read Post #5?

The OP's title asked about <12 cylinders. The answer is zero, so there's nothing much to discuss.
I offered some info on >12 cylinders to show to what else was available. The ">" indicating that I knew they had more than 12 cylinders.
 
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mjfur said:
Did you read Post #5?

The OP's title asked about <12 cylinders. The answer is zero, so there's nothing much to discuss.
I offered some info on >12 cylinders to show to what else was available. The ">" indicating that I knew they had more than 12 cylinders.
Click to expand...
there were many engines with less than 12 cylinders, like the 9 cylinder radials.
 
pbehn said:
there were many engines with less than 12 cylinders, like the 9 cylinder radials.
Click to expand...
IK, but I'm looking for liquid cooled engines with less than 12 cylinders. It seems they don't exist. I was expecting to see some liquid cooled engines within the air cooled DH Gipsy's category of small inline fours, but no.

From an earlier era than we're seeking, but the V-8, liquid-cooled Curtiss OX-5 looks impressive to me. Curtiss OX-5 - Wikipedia

640px-Curtiss_OX-5_1.jpg
 
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Admiral Beez said:
IK, but I'm looking for liquid cooled engines with less than 12 cylinders. It seems they don't exist. I was expecting to see some liquid cooled engines within the air cooled DH Gipsy's category of small inline fours, but no.
Click to expand...
Well DH went as many did, from 4 cylinders, to 6 which had low frontal area and air cooled, the next logical progression if you are going to water cooling is a V12 not a V8.
 
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By the mid to late 30s the small liquid cooled engines were few and far between.

In the US you had the Arrow model F airplane which used a modified Ford Flathead V-8.
Arrow_Model_F.jpg

Arrow Model F - Wikipedia

A Plymouth six cylinder modification had received FAA approval but I don't know what it was used in.
The Funk brothers were building a small two seat plane using a Ford 4 cylinder engine inverted and modified for higher power.
Used in the original Funk Model B airplane.
There may have been a few other engines that popped up for a few years and then died out. A quick scan of the 1938 Janes shows no small water cooled engines.
But since a few people were trying to use motorcycle engines in very small aircraft who knows?

World War I surplus V-8 Hispanos and V-8 Curtiss OX-5s powered many planes in the 1920s but lost favor to the radials despite being cheaper to buy initially.
 
The Rolls-Royce Meteorite was a Merlin with 4 cylinders chopped off and used post war for army vehicles. The Ford V8 V1100 GAA tank engine was a similar cut down V12. I am sure they could have been used in aircraft if there was a need but they can't do anything a 7 or 9 cylinder radial could do cheaper and lighter.
 
There was an advert from post WW1. posted on here that speculated that something like 1 in 10 people would own aircraft in the future. I found this on the Wili site for Allison engine company "In 1929, shortly after the death of James Allison, the company was purchased by the Fisher brothers,[6] who instructed it to use the cylinder design for a six-cylinder engine for a "family aircraft". Before work on this design had progressed very far, Fisher sold the company to General Motors, which ended development due to financial pressures of the Great Depression. Nevertheless, Gilman pressed ahead with the cylinder design, building a "paper project" V-12 engine. The Army was once again uninterested, but instead suggested Allison try selling it to the United States Navy. The Navy agreed to fund development of A and B models to a very limited degree for its airships, until the crash of the USS Macon in 1935, when the Navy's need for a 1,000 hp (750 kW) engine disappeared..
 
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