XFSUgimpLB41X From , joined Dec 1969, posts, RR:
Reply 1, posted (13 years 7 months 2 weeks 6 days 14 hours ago) and read 1424 times:
Haha..i just watched that too. Jet A is cheaper than Avgas. I was wondering about not having a prop and mixture control myself. Most turboprops have a prop control and a throttle or the like.... i guess they will run on a Pilatus like system where it is govered to a certain target RPM. Looks cool though.
MD-90 From , joined Dec 1969, posts, RR:
Reply 2, posted (13 years 7 months 2 weeks 6 days 14 hours ago) and read 1425 times:
The Zoche diesel that makes 300 HP has been in development for some time. Zoche apparently doesn't want to release it until he think's it's perfect. It can run on Jet A or Jet B. It weighs somewhat less than a standard IO-540 or IO-550. It's not turbocharged. Sounds great, but it'll be an uncertified engine (at least at first).
The other is French. They're planning on putting it in some Socatas. I don't know much about it. It will be certified.
The big things about diesels are that they last a long time between overhauls and that kerosene costs a lot less than avgas and it's garanteed to be around 50 years from now.
L-188 From , joined Dec 1969, posts, RR:
Reply 3, posted (13 years 7 months 2 weeks 6 days 7 hours ago) and read 1391 times:
One problem that diesel aircraft engines is that the specification for Jet Fuel does not contain a pectane specification. So the Actual pectane rating for a gallon of Jet A could be all over the place, depending on where you buy your fuel.
What is a pectane specification? Pectane is the readiness of the fuel to ignight. So it is pretty much the opposite of the Octane rating that we are all pretty familiar with. Octane being the fuels resistane to lighting off.
Funny isn't it? Everybody think high octane means really explosive stuff. But the higher the octane number the more stable it is.
This is of course very important for a diesel since the engine is compression ignited. The rule is that the higher the pectane number the easier the fuel is to light off. As a general rule diesel fuel in the US has a very low pectane number with Europe and Japan higher. That is why Diesel engines in those countries generally don't make that clank clank sound you associate with Diesel trucks in the U.S.