This guy doesn't even know that he's talking about the
bottom jugs of a radial engine, which fill up with oil.
Or a horizontally opposed engine, which has been
severely over-primed with fuel, which doesn't compress
either. Great way to bend a connecting rod.
BTW, what is it with the civil war beards? I guess it's
good for guys making movies about the civil war, because
all the potential extras already have the correct facial hair
and they can save $$$ on fake beards?
There's a lot of virtue signaling, and other kinds of social
media signaling going on that I don't understand. If you
have a civil war beard, does it mean that you're signaling
to the other hipsters that don't trim your pubes either, and
you've got some ZZ Top beard action going on downstairs?
This guy doesn't even know that he's talking about the
bottom jugs of a radial engine, which fill up with oil.
Or a horizontally opposed engine, which has been
severely over-primed with fuel, which doesn't compress
either. Great way to bend a connecting rod.
[/quote]
Or an inverted engine, due to oil or fuel under the right conditions.
Interesting video. Here is another about carbs. And you thought you knew how they worked. But I have flown several aircraft types with constant-depression carbs. I think some noise-makers(I mean motorbikes) have them as well. So do aircraft with Marvel H model carbs and the Bing 64 carb on a Rotax,
Re: Aircraft Piston Engines
Posted: Mon Jul 02, 2018 11:02 pm
by Colonel
[quote]Or an inverted engine[/quote]
Right. The PT-19 I used to fly, had a Ranger inverted
six which was really sweet, but I always pulled it through
before start because it was a radial engine with six bottom
cylinders :D
Re: Aircraft Piston Engines
Posted: Tue Jul 03, 2018 1:56 pm
by Colonel
PT-19/26 was an odd airplane. WWII trainer, terribly heavy for the
gasping 200hp engine. It needed some multiple of that - not sure
400hp would have been enough. 600hp would have been better.
One of the best pilots I know - a retired four bar (the real deal)
used to fly a PT-19 decades ago, carried a fine pitch prop and when
he needed to climb, changed props, and when he got back to level
ground, switched props again.
They don't make them like him any more. He was unbelievably unpopular
with the union, who whined to management that it was a matter of
safety, pilots were exhausted and couldn't fly after 85 hours (or whatever)
in a month.
This guy, after his 85 hours were clocked, went and flew bug spray in turkey
bombers. Or, taught Bradley how to fly their 727. Told them he knew shit
about flying up north, but they could teach him that, and he would teach
them to fly a three holer, which he knew like the back of his hand.
He has a cranky between-the-wars biplane with no dihedral on it's long
wings, and a swivelling tailwheel. Designed for a large grass square,
every takeoff and landing into wind. Told him not to fly it on pavement
any more (with a crosswind!) until he installed a locking tailwheel. I
think I have some PIC in it. Talk about a rare type.
What a guy. The Old Breed. God, I miss them. They weren't perfect
but Jesus they had character and depth and buckets of skill and experience
and you could learn [i]so much[/i] from them.
It was great when I could help them out. One day, his biplane was running
like shit, he thought it was mags. I don't know shit about Gypsy Major
engines, but I know about bottom jugs on radials and I asked him when
the last time his plugs were cleaned. Well, it had been a while so I grabbed
these really weird Wentworth tools and pulled the plugs, they were oily and
fouled, replaced them and his engine ran MUCH better.
Aircraft piston engines are all the same. Suck squeeze bang blow.
[quote author=Colonel Sanders link=topic=8669.msg23800#msg23800 date=1530464877]
BTW, what is it with the civil war beards? I guess it's
good for guys making movies about the civil war, because
all the potential extras already have the correct facial hair
and they can save $$$ on fake beards?
♪'Cause every girl crazy 'bout a sharp dressed man♫ ;D
And because I damn well like it. Don't read too deep into it.
Re: Aircraft Piston Engines
Posted: Wed Jul 04, 2018 2:45 am
by Colonel
Ok, thanks. These days I haven't a clue what's socially important and what isn't.
Not that I ever did, but with each passing decade it gets exponentially worse.
Re: Aircraft Piston Engines
Posted: Wed Jul 04, 2018 2:49 am
by Colonel
Back to carburetors.
Lean the mixture.
Lean the mixture after startup, until right before takeoff,
to avoid fouling plugs and building deposits on valves. If
you must sit and wait before takeoff, do it at 1100 RPM,
with the mixture leaned for max RPM. You will not hurt
the engine by leaning it at 1100 RPM, for God's sake. You
lean it too much, it shuts off. Not rocket science.
Lean the mixture for takeoff if the density altitude is high.
Eric and I took off from Flagstaff, NM last summer with a
density altitude of 10,000 feet, waddling out to the runway
loaded to the gills with 100LL and you bet we leaned. Lean
for max RPM, then in a quarter of an inch for detonation. As
if you could make your non-supercharged engine detonate
anyways on 100LL - you don't have the BMEP. Anyways,
Barstow here we come.
Lean the mixture in cruise. Very high density altitude. You
are down on power and pouring fuel through the engine, that
you might need later on in the flight. Lean for max airspeed,
I don't care if you have carb or fuel injection or fixed pitch or
constant speed prop. Ricky Bobby wants to go fast and so
should you. We don't need no stinking engine gauges.
Lean the mixture in descent to keep the engine warm and not
crack the cylinder heads. This knowledge is guarded like the
crown jewels in aviation. I have no fucking clue why, but I
don't know as much about aviation as a TC Inspector.
Lean the mixture after landing. See above. Not the part
about Flagstaff. Nice city, btw. I'd love to live there but
the air is too thin to have fun, except perhaps with hookers
and blow.
Lean the mixture after application of carb heat, because the
hotter air makes it more rich, and that drops the EGT, which
reduces the amount of heat available to melt ice in the carb,
and reduces power.
Lean the mixture.
Next time, we discuss why you should wear three condoms,
especially with the hookers in Flagstaff.