Didn't the old Avro Shackleton have a dual prop setup too? I know the old Merlin engines had about a 50 gal per hour burn, so in a Lanc, that was 200 gallons per hour. wow! I think they built them (radial) lose for a reason. I think Colt built their 1911 .45s that way for similar reasons. If you even hear a radial idle on the ground, you think they're going to fall apart. hee hee
Zeb > air cooled 911 engine, but built a little tighter. Then again, not as far to fall if it stops working. :-) On 19/01/07, Peter Frederick <[EMAIL PROTECTED]> wrote:
I heard from a WWII airman that a B-26 used 50 gal of fuel and 5 gal of oil and hour in cruise flight, more at full throttle. Those old radial engines were "sloppy" -- oil dribbled out the pushrod tubes, the head gaskets, and jug seals, and they do burn quite a bit. 1940's technology, mostly -- cars used a lot of oil in those days, too. Newer design are better, but so long as they are air cooled, they run pretty hot by water cooled standards, and it's hard to keep them sealed up. They all use dry sumps -- there is an oil collection ring on either side of the single crankpin where the oil collects and it's pumped form there back into the main tank where the air bubbles separate out. The pressure feed pump draws off the bottom of the main tank instead of the crankcase. Some designs used "stacked" pumps (scavenger on top, feed on bottom) on a common shaft -- that way you at least had sump oiling. When the feed pump shears, two things used to happen: The pilot lost control of the propellor pitch (oil pressure operated) and the engine seized from oil starvation and usually the oil on the engine caught fire from the heat -- there are plenty of stories about this. Pan Am and BOAC both had at least one instance where the magnesium propellor housing caught fire on a seized engine at altitude when the oil pressure dropped too fast to feather out the prop -- must have been quite a sight, burning magnesium spinning off the blades. Luckily, the housing failed and the prop spun off and away from the airframe before the wing burned throught on that Boeing 377, and the fire went out. An oil pressure failure caused Howard Hughes to crash the experimental twin interceptor during WWII -- an oil seal failed on the counter-rotating prop system causing loss of pressure and inadvertent reverse pitch on one side. Needless to say, the plane instantly became unflyable with power on that engine. He'd probably been OK if he'd understood what was going on in time to shut the engine off, but it's rather hard, I hear, to figure that out during a flight emergency.... Odd that only the Russians managed to get a reliable counter-rotating dual prop setup to work during the 50's -- very well, too as the Tupolev Bear uses them, along with any number of freighter designs. Peter _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
