Ok, we got room for guns, now, where do we put the ammoBf 109H-4, deployed against Soviet Union starting from August 1941.
Powered by the BMW 809 ( ) engine - 36L, 750 kg, fuel injection, 1550 HP down low, 1330 HP at 5.7 km - and armed with four cannons. Praised for it's firepower and performance, as well as the wide-set undercarriage and good visibility.
(rotated the pic made by T. Mohr almost 60 years ago, denoting 2x MK 151/20 and 2x MGFFM)
As you state cooling the heads was an issue. The legendary Porsche 959 used water cooled heads to solve that problem while retaining the traditional air cooled barrels.In engine/fuel terms air cooled engines (high performance) were considered as "severe" duty engines. The air cooled engines were more prone to isolated hot spots in the cylinder heads while the water cooled engines averaged the temperatures better, not saying that were not hot spots. The Air cooled engines were running closer to the detonation limits.
As you state cooling the heads was an issue. The legendary Porsche 959 used water cooled heads to solve that problem while retaining the traditional air cooled barrels.
It also had a longer life and didn't have the engine fires the R-975 was prone to. The R-975 was also prone to hydraulic lock resulting in bent/broken conrods. Nicholas Moran (aka the Chieftain) has excerpts from the US Army equipment reports on his website. I am having difficulty finding the second part which has specific info on the R-975 but here is the first partThe eventual Ford GAA had 100 more horsepower than the the wright radial in the Sherman and was more reliable.
What problem did the BMW 810 solve other than being an available alternate to the Daimler Benz DB601? Are you assuming that radial engines are automatically superior to liquid cooled V12s?Unlike, say, USA or Japan, there was only one German radial engine in-service that is worth talking about - BMW 801 - with two 9 cyl radials whose genealogy can be traced to 1920s. BMW 800 project never materialized, while really big radials also meant nothing at the end of the day.
Premise of the thread is that engine companies are pushed earlier towards the own development, so there is more to choose from, so to say. Small radials (9 or even 7 cyl) can be a made instead of the air-cooled V12s, while being lighter, cheaper and making a bit better power. Small to medium sized 14 cyl can be alternative engine for bombers and even fighters (German fighters were small and light, to help out wrt. performance even if the engine power is not over the top). 18 cyl engines can be alternative to the complicated and troublesome 24 cyl liquid engines like the Jumo 222, DB 606/610 etc.
For the needs of this thread, Jumo and DB remain in the liquid cooled engines' business. Merge the other companies as you see fit, and probably as early as possible, and kill of designs you see fit. No licence deals with foreign companies.
You are certainly free to either take part in the thread with less of an attitude, or to ignore the thread.What problem did the BMW 810 solve other than being an available alternate to the Daimler Benz DB601? Are you assuming that radial engines are automatically superior to liquid cooled V12s?
The Germans failed to develop two-stage supercharges and high octane fuel. This limited the BMW801s just as much as the DB601s and DB605s.
Each type of engine has advantages and disadvantages. How well the designers manage or cope with problems while utilizing the advantages tends to make the specific engines successful or failures.
Sometimes engines have directly conflicting attributes.
Like large radials often have more cylinders which means that the cylinders are smaller, easier to cool, have greater volumetric efficiency and probably a few other things, like short stroke means lower piston speed.
However when you put 7 or 9 cylinders on one crankpin piston speed may not be the limiting factor on rpm.
Using air instead of liquid cooling also changes the cooling problems. Liquid cooled radials never made it to production after WW I?
For the German companies in particular, they haven't designed a 'military grade' radial for some 20 years - between end of ww1 and BMW 139 and Bramo 14-cyl radial that gotten nowhere?
Perhaps merge Bramo and Argus, as well as BMW with Hirth, all by 1936?
Perhaps from this perspective focusing on inlines was a better choice; less conspicuous and can maybe be explained away "oh this is for a racing boat"? Then again, given the thinking in Europe at the time that fast aircraft needed inlines, developing big radials maybe could be explained as being for upcoming civilian aircraft (which, per se, wouldn't even need to be a lie)?
Do these have the R&D muscle to develop high power radials? Also, starting in 1936 is still quite late if we want a radial replacement for the Jumo 211?
Alternatively, what if Junkers "sees the light" in the 1920'ies and decides that radials are the future? That would give plenty of time to develop a few smaller radials to learn the ropes, and then develop one or two high power ones in time for WWII?
Note that I've listed both Jumo and DB keeping with liquid cooled engines for the purposes of this thread
Junkers, seeing the lackluster success of the 211, forgoes the 222 and makes a "213 lite" which is essentially a 211 with pressure cooling, sturdier components for higher rpm, a 4V head, and then concentrates on jet development.