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Continental designed engines in a simpler time, when aircraft did what you told them to do.
This is not the behavior that pilots are looking for in the 21st Century.
Maybe so, but I still liken it to how at the other end of things my engine shouldn’t quit if I pull power to idle with carb heat hot at the end of my run up. It’s a matter of adjusting the carb/injection/FCU/FADEC accordingly. I’m well capable of limiting movement accordingly if it does quit and I don’t think it makes me particularly dumb or lazy to want it to be better than that.
Again I’d be interested in knowing if there’s a benefit elsewhere in a system that allows the engine to run critically over rich on takeoff. You know, to help build wisdom on top of the knowledge already established here.
Either the mechanical or electric boost pump on a Continental are designed
to be able to deliver the full requirement of fuel at WOT. Ask anyone who
has installed and calibrated a new fuel injected Continental - the system is
already complex enough, and I think you are suggesting that the system should
be more complex and expensive with a new, additional over-pressure system
which limits the fuel to the engine. What could possibly go wrong?
Think about the failure modes of that new system that you are proposing.
In engineering, there is often great value in simplicity. If it's not there:
1) you don't have to pay for it,
2) you don't have the additional weight of it,
3) you don't have to maintain it, and
4) it won't try to kill you when it breaks.
I am perfectly happy with an airplane that does exactly what I tell it to do.
I don't need additional safety systems that are going to try to kill me, one day.
I know as a 20th Century pilot I'm not very bright, but once more, I will point
out the value of systems knowledge and fundamental aircraft handling skills.
The L39 has a secondary FCU which is manually enabled by the pilot after the
primary FCU fails. I am ok with that, but I realize I belong in a museum, jail
or cemetery.
The L39 ECS also has a manual setting which if full HOT temperature is selected,
will feed bleed air directly into the cockpit. I am also ok with that, because I
don't have a problem with an aircraft doing what I tell it to do.
All of the fuel-injected piston engines I fly, will allow me to over-prime on start
to the point that I hydraulic lock during start, and bend the connecting rods. Or
merely light it on fire. There is no complicated system to stop me from doing that,
either.
There is no complicated guard on the propeller on any of the aircraft that I fly,
to stop someone or something from walking into the prop when it is rotating and
invisible. That's pretty fucking serious, isn't it?
I guess as a 20th Century pilot, I might observe that despite how much people
want to remove brains as a requirement to be a pilot, some are required. Not
much, but some.
The advantage of any ancient mechanical fuel injection system - it has no Venturi
to ice up, like a carburetor ... and will feed inverted - far outweighs it disadvantages.
Again, I'm not too bright, and I've spent decades jumping from fuel-injected TCM
to fuel-injected Lycoming, frequently both in one day. No checklist. And I haven't
had a problem in the last 49 years. Neither has my father and my son, and TC thinks
they're both pretty shitty pilots.
If I'm the stupidest person and the worst pilot in Canada, and do not deserve citizenship
any more - I accept that narrative - therefore all the brighter people and better pilots
and more virtuous people shouldn't have a problem with it, either.
As God as my witness, I thought turkeys could fly.
Lycoming fuel injection is shit. I own three of them. There is no return
line, and they are difficult to hot start and terribly prone to engine fires
on start.
Contrast that to Continental fuel injection, which is so easy to hot start.
You think there is no cost to hot start problems?
Talk to me about Lycoming fuel injection dividers. You know how many
people they have killed? Do those people have no virtue?
I don't do pattern work over 95F with Lycoming fuel injection. That lesson
was painfully learned.
Ever heard of the USAF? They learned the hard way about Lycoming fuel
injection:
The Commander of the Air Education and Training Command stood down the entire T-3A fleet in July 1997 as a result of uncommanded engine stoppages during flight and ground operations.
It's shit.
Guess what airplane the T-3A replaced? Yes, the T-41 which has the fuel
injected Continental, which worked just fine for fucking decades.
Yeah, I'm such a fucking moron.
As God as my witness, I thought turkeys could fly.
I am reminded of cold winters. I have seen pilots inadvertently stop the prop on
final, because they did a low-power descent in very cold air. There is no complicated
system to prevent that, either.
Hell, 10 miles back from the airport, if you pull the throttle to idle and try to maintain
1000 feet, you're going to stall. And maybe spin. No complicated system to prevent
that, either.
I can do this all day. Some brains are required to be a pilot, regardless of the strong
desire for egalitarianism in 21st Century culture, which as we all know is more important
than safety.
I say again: some systems knowledge and basic aircraft handling skills are fundamental
to a pilot. Can't get away from either one. Sooner or later, ignorance and incompetence
catches up with the most virtuous pilot.
As God as my witness, I thought turkeys could fly.
I'm starting to become a TCM fan boy, just like my Glocks.
I've flown behind injected Lyc's in the PA32 and PA31. No problems, but I can remember looking like an amateur (which in some regard I still was) trying to hot start them, after a quick turn.
Now, both of my Continentals (O-470's) have been running really well. I do oil analysis every oil change (50 hours). The metals have been consistent the last 4 cycles, so I might roll it back to every other oil change.
Irregardlessly-ness, knowing when to head back to the FBO for more coffee is a hard lesson to learn. But I imagine much cheaper than death. But I've never died, so I don't know what that costs yet.
Both the TCM and Lycoming fuel injection systems have their strengths
and weaknesses. As a pilot, it behooves you to learn about the strengths
(and use them) and their weaknesses (and avoid and baby them).
I cannot imagine being one of those pilots that thinks that there is magic
pixie dust or some shit under the cowl that makes thrust.
PS. Dying isn't so bad. Just don't look bad when you do it, ok? There's
a million ways to do anything, so learn from
"When asked for any last words, Gilmore simply replied, "Let's do it."
See Nike and Home Depot. I am not making this up. Over 40 years after his
death by firing squad, the last three words he uttered still form the foundation
of the advertising campaigns of two large multi-national corporations.
Not one - TWO. Can any Madison Ave Ad firm make such a claim?
That's the way to do it! Let's do it!
As God as my witness, I thought turkeys could fly.
$10 says he learned to fly on a Lycoming fuel injected engine, and he
tried to take off with the boost pump on, with a CONTINENTAL fuel
injected engine!
Note that the last 3 days it's been hotter than hell when I've flown, and
boost pump was ON - for LYCOMING.
I've spent the last 49 years flying behind a fuel-injected Continental -
with the boost pump OFF for takeoff and landing!
Could you elaborate on the reasons why the two engines operate differently? Is there some fundamental difference in fuel system architecture that causes the opposite procedures?
You note that your boost pump is "ON - for a LYCOMING" when "it's been hotter than hell". Would it be different in cool weather?
My homebuilt will have the Precision SilverHawk injection (basically the Bendix type mechanical injection) with an overly expensive Andair boost pump. Both produce nominally 25-30 psi at 16 GPH. My intent had been to use the boost pump only for priming and loss-of-power emergencies. The system is basically tank in front of the panel, boost pump on the cool side of the firewall leading to the high pressure gascolator, then straight to the injector and up to the flow divider. No return line with this system, just as simple as I can make it.
I'd appreciate your advice, I want to run the thing as intelligently as I can.
I run the boost pump ON with a Lycoming, any time I would be really upset
if the engine fails. Certainly below 1000 AGL.
It depends on the installation, but my experience has been that in cooler wx
the IO-5xx or IO-3xx Lycoming runs fine without the boost pump. But I don't
like to leave that to chance.
In the heat of summer, the fuel-injected Lycoming will fart and burp as the
fuel boils in the injector lines on top of the very hot engine, esp after landing,
hence no pattern work over 95F. You need to make sure that the piston in
the fuel divider will not stick.
I'm not sure who designed your fuel system, but I would start with them, or
whatever documentation is available. Did you copy a particular aircraft
installation? That's pretty common for homebuilts. Note that high wing
vs low wing can make a big difference, as does running the fuel line past
some heat, and also running mogas which vaporizes far too easily in some
installations.
With my fuel-injected TCM, if I select boost pump on at idle, black smoke
will start to belch out the exhaust like an old diesel, and the RPM will start
to fall and the engine might quit, it's so rich. This is not hard to detect.
With a fuel-injected Lycoming, if I select boost pump on at idle, I might see
an additional 0.1 GPH and I might not.
Suggestion: instrument your fuel flow GPH and your fuel PSI. It will tell you
what your engine is seeing.
PS. Over the decades, I have spent enough on certified electric boost pumps
for a really spectacular weekend in Vegas. Weldon, Dukes, you name it. Aft
of the firewall is probably better, but I've seen forward of the firewall too.
In my experience, mounting the electronics aft of the firewall is not optional.
As God as my witness, I thought turkeys could fly.
The engine is a mix of yellow tag used and new parts, from various manufacturers. Case is new Superior, crank and cam are Lyco yellow tag refurbs, cylinders are Titan (no not the AD ones) with the pistons and valve trains. Sump is the forward facing Superior. Nearest equivalent in a stock Lycoming would be the 180 hp IO360-B1A. As I mentioned the injection is Precision. I've not copied any particular installation, but the manual is being followed very closely. All fuel and oil lines in front of the firewall will be stainless sheathed with fire sleeves as well. I've not built much forward of the firewall yet, but I'm very cognizant of keeping the fuel lines away from the exhaust, we'll see how much room I've got when I get there.
Instrument panel is Dynon, we'll have the full complement of engine sensors installed and regularly reviewed.
