I will suggest the entire lineup of VW engines going way back to the earliest turbo indirect engines. They used the same dimensions of rotating elements and often the exact same parts. You KNOW why "they have larger/thicker pistons, etc." - simply because the RPM at which they are designed to make the HP and torque they are able to do - something most SI engines simply can NOT do because of detonation issues. That makes a car or truck so much nicer to drive when the fat part of the power curve is at cruising RPM (and, yes, I realize many SI engines are now learning to do this reasonably well - but diesels can do so until they run into some thermal or mechanical strength limit - and at same cylinder pressures so would an SI engine...IF it could run on an aspirated charge without detonating. Of course, in aviation this means direct drive is easy whereas to get those kinds of numbers out of an SI engine, it has to be wound up like a $2 watch.Ok, show me a modern diesel of the same hp which weighs less than a modern than a modern SI turbo engine. How could a diesel be lighter? They have larger/ thicker pistons, rods, wrist pins, cranks and blocks.
again, I am totally unfamiliar with the "320 T" engine, but you put forward your very best at 40% BTE and the diesel people did theirs at 50% - so all of the theoretical advantages of the Otto cycle of the Diesel cycle just aren't materializing.Let's compare modern aero diesels to modern liquid cooled SI engines like the 320T. Comparable cruise BSFC figures to diesels and much better power to weight ratios.
True of a naturally aspirated engine - but the next thing you will see is e-turbos on aero diesels that can start at virtually any altitude and temperature with ease.The diesel won't start above 18,000 feet (or even 12,000 in some cases) because the ambient pressure is too low.
I have lived and worked in the arctic and sub arctic for decades. We use Jet B for that reason, but modern HPCR diesel have so much injection pressure the get fantastic atomisation at ridiculously low ambient temps. Starting is simply not an issue.The Austro AE300/330 is limited to -30C with Jet A and -5C with diesel.
BUT: when the zombie appocolypse comes, there won't BE any Swift 94 or LL100 - but we dieselheads can stick up Rotten Ronnies and get into the air.Of course SI engines don't burn old fryer oil... I don't see your point here. We'll be filling up at airports in most cases with 100LL, mogas or maybe unleaded avgas like Swift 94 or 100.
agreed, but the injection pressures in a turbine are miniscule compared with HPCR engines (that go up to 29,000 psi). This is one of the struggles in the aerodiesel design community: have a simple mechanical system and be stuck with low pressures and sensitivity to viscosity or go with full electronics so the programming boffins can make the engine dance on stars....at the expense of being 100% electric dependent. As I mentioned, we start diesels every day in cold places, and modern HPCR engines with ULSD do so very well indeed.[/quote]Most turbine aircraft have fuel heaters just because you have pumping, gelling and vaporization issues below about -45C. Diesel aircraft will have the same issues.