I certainly brought out the big guns, thx.DB607 was meant for bombers/long distance flight (and not at very high altitudes). The take off power of 1750PS was actually achieved by using Alchohol fuel, so you need
two fuel tanks (I dont have the particulars of how that system worked annoyingly), and the 607 was down to 625PS by 33,000feet altitude (a bog standard 605A at that point was 790PS, a 603A was 950PS and even an old 601E has 700 at 33,000ft). Diesels tend to have high airflow per unit power, as they need to run pretty lean, so this places a higher
demand on the supercharger size, so they dont make brilliant engines for very high altitudes without being turbocharged - which totally counts them out for any
German single seat fighter.
Today because of the more advanced state of turbocharging, it is a possibility again to make a high performance aviation diesel with good altitude performance, with a reasonable
package size and overall weight.
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Thanks for the information on DB 607, wasn't aware that it was to run on alcohol for take off.
While diesels remain functional at very lean mixtures - the old tractor idled at air-fuel ratios of near 100:1, do they need to? The same old tractor made some serious power when injector pump was screwed in. And lots of truckers in Americas make wild power while "rolling coal". I'm having to do some airflow calculations here - the engine rpm differences between the automotive engines - diesel versus gas make direct comparisons challenging.
There's a lot of improvement over past 90 years, not just turbocharging, but some forgotten technology on the gear drives too.