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Another factor may be the limited RPM range of a diesel. Not familiar with aero diesels, but a 3406 Cat, for instance, has a power band from 1500-2100 RPM. A similar power gas engine will have a band much wider, like up to 3300 RPM for a Griffon-like engine. That's one reason why gas engines remained common in tanks, the wider power band required less gear shifting. A diesel aero engine would require a much more sensitive CSU (governor) to adapt to throttle settings.
As anything.It depends on how how much you pushed them.
I wrote "generally" precisely with the purpose of avoiding anecdotal stories. Not hard to believe that an engine break down every now and then. This shows that radial engines have a tendency to throw cylinders around as champagne corks?Bristol launched...
This is not exactly surprising.As some engines progressed (like the Wright Cyclone) from 5-600 hp engines in the late 20s to 1400-1500hp engines post WW II the number and size of the cylinder hold down bolts changed.
Had someone proposed to exceed some limit?Limits were established in the test houses/ test stands and as long as those limits were observed little trouble was had, exceeding those limits...
Supercharging (even better turbocharging) is the perfect addition to a diesel engine, while it causes some more problems do deal with in the gasoline engine (detonation). The disadvantage is the need to have a very precise timing system for the direct injection. Obtaining it mechanically (the real innovation of the common rail of the '90s is the use of ECU commanded and electrically activated valves) isn't easy.One thing to mention: diesels would have been much more suitable for pure turbocharging (no mechanical engine stage at all) than WW2 SI engines due to their significantly lower exhaust gas temperature plus that they had no carb to deal with. With turbocharging the power/weight ratio could have been significantly improved.
What noise? A turbodiesel had a low exhaust noise, since the exhaust gasses are silenced by the turbo itself. The combustion / mechanical noise, that is high in diesels, is another face of the mechanical stress, an yes, it was lowered by electronic controlled direct injection.I disagree with Dogwalker. E.g. the primary reason for those multiple sprays is noise reduction,
Low pressure '80s diesels were prechamber / indirect-injection ones. More weight, less fuel efficiency, less thermal efficiency, and less benefits / more danger in being turbocharged than a direct injection one.not stress reduction. Speaking of injection pressures, a common automobile diesel of the 1980s had an injection pressure of less than 200 bars. The injection pressure of the Jumo 205 was some 550 bars.
May be that the raising of performances, and lowering of weight, specifically since the direct injection has become common in diesels, came from the sky.I'd say that whoever claims that electronically controlled common rail injection has improved power/weight or power/displacement in any significant way is exaggerating quite a bit
Quite strange, since I happened to read it several times.No offense, but at least in automobile manufacturers' own advertizing material it is clearly stated that multi-phasing of injection is primarily intended to make the engines less noisy plus to reduce emissions. Not in a single text has it been stated that it is intended to prolong engine life and/or reliability.
And those that were not prechamber had 200 bar pressure of the injector?Not all 1980s diesels were prechamber.
The prechamber diesels main attraction is to have less pressure / longer time injection, so to need less precise injection time. I already explained the drawbacks.And even then pre-chamber diesels' main attraction was softer noise.
Precisely were RPM are lower and so injection timing could be less precise. Who knows why...Plus in construction machinery, tractors etc. direct injection has been significant for quite a while.
Have I EVER said "impossible", or that "none has been done"? I Already posted another that had.Even WW2 diesels like the Soviet V-2 tank diesel had direct injection. And that engine had excellent power/weight ratio.
Rare? Prechamber turbodiesels, injecting fuel during compression, to have little more than mediocre performances needed MASSIVE intercoolers to avoid preignition and a hole in the piston. It was part of the inefficiency of the formula, and of the causes that have made that it was erased as soon as a reliable form of direct injection has been available. You are reasoning as direct injection and turbocharging are independent variables. They are not.As for the improvements in performance, the main reason for that has been with at least 99 % share of the impact has been turbocharging (especially variable geometry turbochargers) coupled with intercooling. In the 1980s intercooling was quite rare.
The fact that you have decided that way does not means that's true.Yes, turbocharging and direct injection are independent variables.
It's not so difficult to read the posts and see how the discussion has gone that way.Plus, why speak of direct injection when your original claim was electronically controlled common rail injection and its blessings on power increases?
I'm very sorry for Mr. Savolainen, who probably has the only fault of his work being misquoted.Regarding pre-chamber engines, the "automobile technical handbook" by Pentti O. Savolainen...