Doubling down: H16 engines for everyone

[tomo pauk]

... so that other countries making the engines in the 1930s-40s don't feel neglected. So the French make HS 16Y instead of the 18Y, RR makes the Merlin-based H16 (or even the Buzzard-Griffon-based H16), Allison makes a V-1710-based H16, Chrysler makes a H-2200 instead of IV-2200, Napier makes one big & powerful H16 instead of Sabre etc.

Cancel the other types that are getting in the way in the respective companies. There is no requirement for sleeve valves to be incorporated.

Shortening of the stroke is allowed, so that engines are less bulky, and the RPM can go up. Motor-cannon installation where wanted/desired/required. Engines for fighters and bombers alike. USAAC/AAF will probably want to support the engine with a turbo. 2-stage superchargers by mid war, at least by the companies that were making these by early/mid-war.
Engine halves can operate independently if wanted.

 

[Shortround6]

Motor-cannon installation where wanted/desired/required.

Plus and minus. The Sabre used common cylinder blocks. The Cylinders going the same way (left or right on the sideways engine) were cast as a 12 cylinder assembley. didn't leave much room for a motor-cannon. Some H style engines used four separate blocks. However this means the blocks have to be further apart than they need to be for just the engine needs. The V engines have some room in the V depending on accessories and misfolding.
H engine needs off-set reduction gear to hold the Cannon. So did the V but the V puts the cannon closer to the center of the engine (distance from crankshaft/bottom of crankcase to tops of the cylinder heads. With the H the crankshafts need to be further apart. Now perhaps they need to be for manifold requirements?

Engine halves can operate independently if wanted.

This sounds good. May or may not lead to problems.
If you cannot synchronize the engines this means that one engine operating 24 rpm off from the other at 2000rpm (cruising) and using 2 to 1 reduction gear (1000rpm propeller rpm, 12rpm different) has one propeller "passing" the other 12 times a minute. Yes they are countra rotating but this constantly changing pattern of overlap may be nothing or it might show up vibration problems.

 

[GrauGeist]

Tomo, can we include Continental's proposed H-2860, which was derived from their I-1430 engine?

 

[Shortround6]

You could take the old hacksaw to the Lycoming XH-2470 but then you have a XH-1644 engine which is not likely to impress anyone, even if it actually worked.

Lycoming XH-2470 24-Cylinder Aircraft Engine

Lycoming worked to create a new engine by combining components from two O-1230 engines. The new engine was known as the XH-2470, but it was not developed in time to benefit the US Armed Forces.

oldmachinepress.com

1425hp at 15,000ft for a two speed engine that weighed around 1800lbs? (75% of the weight of the XH-2470)

The attached page has a drawing with dimensions

Granted the two American engines (this one and the above mentioned Continental) have some serious flaws, like the separate cylinder construction (overly long and weak to boot) and the 2 valves per cylinder. Granted a 4 cylinder length block/crank may help with the length and the weakness compared to the original 6 cylinder per bank length.
But you are going to need a crap load more RPM to equal a Griffon engine.

Go back to the drawing. 44in (1.12 meters) in height for an engine using 4.75 in/120mm stroke. and that is just over the valve covers. 50in (1.27m) over all over the breathers and oil sumps.

 

[GrauGeist]

If I'm not mistaken, Continental eventually fitted the I-1430 with two sodium filled exhaust valves per cylinder, plus the I-1430's heads were hemispherical.

 

[tomo pauk]

Tomo, can we include Continental's proposed H-2860, which was derived from their I-1430 engine?

Why not.
The 16 cyl derivative might've been called the H-1900 (= 1430 x 1.33). As noted by S Shortround6 above, the individual cylinders might be a liability, and the valvetrain will need to be updated. If we accept the 1300-1350 HP power as realistic for the I-1430, the H-1900 should've been making around 1750 HP military power. 2000 HP WER if the cylinders are okay with this; dry weight - 950 kg? P-40 and P-51 should've been interesting with these, if the engine matures in a timely manner.

Allison H-2260 (ie. 1710 x 1.33) - 1500-2000 HP military/TO power, 2000-2100 HP WER, 2400 with ADI? Might be a good fit to a P-47/-72 (= have "Fisher body division" make these instead of the P-75?), B-29, B-25/-26, A-26 (yes, I know that USAAF was not keen on liquid cooled engines on the 'attack' aircraft category).
Similar story with the 16-cyl H-2200 by Chrysler.
'Target weight' of a bit above 1000 kg?


For the British - the Merlin-based H16 engine instead of the Vulture should've been a very interesting and useful engine. Talk mimicking the H-2200/2260 in shape, size and weight, for installation on the Typhoon/Tempest, and a slew of FAA aircraft (Fulmar might be too early for this, but Barracuda, Firefly and Sea Fury might match the timing). A bit better power than the US competition in the same period, due to the Merlin's timing and genes?

The not-Sabre - perhaps Napier going for an 'square' engine (= bore equal to the stroke) for a more compact and higher revving engine?
'Target weight' of ~1100 kg (ie. similar as the Vulture and Sabre)?

 

[Frank Stewart]

... so that other countries making the engines in the 1930s-40s don't feel neglected. So the French make HS 16Y instead of the 18Y, RR makes the Merlin-based H16 (or even the Buzzard-Griffon-based H16), Allison makes a V-1710-based H16, Chrysler makes a H-2200 instead of IV-2200, Napier makes one big & powerful H16 instead of Sabre etc.

Cancel the other types that are getting in the way in the respective companies. There is no requirement for sleeve valves to be incorporated.

Shortening of the stroke is allowed, so that engines are less bulky, and the RPM can go up. Motor-cannon installation where wanted/desired/required. Engines for fighters and bombers alike. USAAC/AAF will probably want to support the engine with a turbo. 2-stage superchargers by mid war, at least by the companies that were making these by early/mid-war.
Engine halves can operate independently if wanted.

Why would you want to do that? With conventional Valves, the "X"-24 is a better idea. The sleeve valves in the Saber were a bottle neck all on their own. But most important of all is that there were better, more powerful, economical and plentiful air-cooled Radials that could have done the same jobs so much cheaper! Cheaper wins wars, complex loses them!

 

[tomo pauk]

Why would you want to do that? With conventional Valves, the "X"-24 is a better idea.

More HP, in a package that is better suited for a retrofit than a 24 cyl engine with the same genes.

But most important of all is that there were better, more powerful, economical and plentiful air-cooled Radials that could have done the same jobs so much cheaper! Cheaper wins wars, complex loses them!

Cheap, non-complex aircraft like the P-47, P-38 or B-29 you mean?