Author Topic: Request: Aircraft Piston Engines 101  (Read 10099 times)

Offline Frank N. O.

  • Alpha Rooster
  • *****
  • Posts: 2446
  • Spin It!
Request: Aircraft Piston Engines 101
« on: November 18, 2007, 08:50:55 PM »
Ok actually I'm not exactly sure what 101 means other that it's usually something written after US school classes so I figured it meant Level or something like that.

I know a fair bit about Otto-engines for cars, but what's the basic configuration of an aircraft engine and what needs to be adjusted regularly on it?

As far as I've picked up then an average aircraft piston engine is a flat-engine with a central camshaft and magneto ignition with two spark plugs per cylinder and air cooling, and some have carburators and others have fuel-injection (mechanical only I'd imagine), but what about the other aspects?
Is it a single cylinderhead per bank or seperate per cylinder like Scania-trucks for instance?
I can imagine there are only 2 valves per cylinder on any aircraft engine but are they overhead? Do they have mechanical valve-lifters that need periodic adjustment or are they service-free hydralic ones? Is the camshaft a std. or roller-type?
Do they use cross-flow cylinderheads?
What kind of firing order do they have? Like a boxer-engine or a V? (two at the same time or two pistons on the same part of he crankshaft giving more vibration, I can definately remember the Cardinal RG I flew in really shook hard when the engine stopped).
Do they use wet or dry-sump lubrication and is there an oil-cooler? And do aircraft engines use oil-spray underneath the pistons to cool then down like some car-engines?
Is it a mono or multi-point fuel-delivery? (one nozzle per cylinder or one for all).
What does an average aircraft engine weigh?

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
— Leonardo da Vinci

Offline AirScorp

  • Rooster
  • ****
  • Posts: 369
  • Nick
    • Me on myspace
Re: Request: Aircraft Piston Engines 101
« Reply #1 on: November 19, 2007, 01:49:15 AM »
Frank, I always thought of 101 etc. like chapters in a book. First is chapter 1.01, then goes to 1.02, 1.03.. Then you go to a new "more advanced chapter" and start again 2.01, 3.01 etc. Then again, I'm Greek :)

As for your question, I'm like you so no real answers, what I do know is that most "simple" engines are dry-sump lubricated. That much I remember from the books..

Why not start at a place like http://en.wikipedia.org/wiki/List_of_aircraft_engines and check out the Lycomings and Rotaxes for a start?

And remember, the smaller the airplane, the simpler the engine will be in most cases. Makes sense to be easy to maintain.
« Last Edit: November 19, 2007, 01:53:09 AM by AirScorp »
It's all Greek to me!

Offline BrianGMFS

  • Rooster
  • ****
  • Posts: 429
  • My other car is a Firefly
Re: Request: Aircraft Piston Engines 101
« Reply #2 on: November 19, 2007, 02:38:11 AM »
While I'm not a Mechanic...... I do work in an aircraft repair shop. Most aircraft piston engines are horizontally opposed four or six cylinder powerplants. Each cylinder is a separate part. Much like a motorcycles air cooled engine or the old style VW Bug.

Here's a couple of shots showing the two extremes of aircraft engines. The first is an old tired Grumman Tiger in for major maintenance...



The next one is a brand new turbocharged Cirrus SR-22 Gen 3



And the last is the engine on a kit built Lancair IV-P with Twin turbos (in for avionics work)



Brian


-

"Take my love, take my land. Take me where I cannot stand. Burn the land and boil the sea, you can't take the sky from me."

Offline Fabo

  • Chicken Farmer
  • Alpha Rooster
  • *****
  • Posts: 967
  • If flying is a drug,then I am a first class addict
Re: Request: Aircraft Piston Engines 101
« Reply #3 on: November 19, 2007, 01:55:47 PM »
Me likes the first one the best ::loony:: ::rofl::
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."

airtac

  • Guest
Re: Request: Aircraft Piston Engines 101
« Reply #4 on: November 19, 2007, 03:32:45 PM »
Thing I noticed is what I look for when I take an airplane to have maintenence done---a clean shop |:)\

That Tiger, incidently, looks likes it's been rode hard and put away wet ::eek::

Offline PiperGirl

  • Rooster
  • ****
  • Posts: 278
Re: Request: Aircraft Piston Engines 101
« Reply #5 on: November 19, 2007, 04:38:51 PM »
Nice clean shop there. It's always nice to see a clean area.
No guilt in life, no fear in death /This is the power of Christ in me /From life’s first cry to final breath /Jesus commands my destiny~ Newsboys "In Christ Alone"

Offline BrianGMFS

  • Rooster
  • ****
  • Posts: 429
  • My other car is a Firefly
Re: Request: Aircraft Piston Engines 101
« Reply #6 on: November 20, 2007, 04:05:26 AM »
Thanks for the comments on the hangar floor. One of my more "pain in the butt" jobs during the day is cleaning the hangar floor  ::banghead:: The hangar is 120 feet by 100 feet. We have a walk behind floor scrubber that helps somewhat but it still can be a pain ::rofl:: I don't know how many times someone has come into the hangar as said how clean it looked and I look at it and say this is what we consider a dirty floor  ::loony::

Here's a shot to show the size. in the shot is a Challenger, Citation Excel and a C-90 King Air with room for a few more planes


or for those of you who know how big a DC-3 is in real life.... Plenty of room to spare


That Tiger is pretty beat... it has only seen the inside of a hangar when it's getting worked on. This Annual is really gonna cost some $$$$

Brian


-

"Take my love, take my land. Take me where I cannot stand. Burn the land and boil the sea, you can't take the sky from me."

Offline undatc

  • Alpha Rooster
  • *****
  • Posts: 551
  • Standby, I have your request......
Re: Request: Aircraft Piston Engines 101
« Reply #7 on: November 20, 2007, 06:10:18 AM »
Brand new cirrus and already in for work.   ::banghead::

On the note about cirrus, I didn't know till about two weeks ago, one of their main plants is here in town.  Had to deliver a pizza to their building.
-the content of the previous post does not represent the opinions of the FAA or NATCA, and is my own personal opinion...

Offline BrianGMFS

  • Rooster
  • ****
  • Posts: 429
  • My other car is a Firefly
Re: Request: Aircraft Piston Engines 101
« Reply #8 on: November 20, 2007, 02:14:17 PM »
Quote
Brand new cirrus and already in for work.

Yep... Not Cirrus' fault.... I think the owner could grenade a lawnmower, let alone a turbo'd Continental. We've hung one complete engine (prop strike) and 3 cylinders on his Mooney 231 and so far one new jug on his Cirrus. The mechanics in the shop think he runs it WAYYY too lean and burns pistons.

Brian

-

"Take my love, take my land. Take me where I cannot stand. Burn the land and boil the sea, you can't take the sky from me."

Offline Rooster Cruiser

  • Alpha Rooster
  • *****
  • Posts: 1996
  • Retired Chicken Hauler
Re: Request: Aircraft Piston Engines 101
« Reply #9 on: November 20, 2007, 03:34:31 PM »
Quote
Brand new cirrus and already in for work.

...The mechanics in the shop think he runs it WAYYY too lean and burns pistons.

Brian

This was exactly my thought when I saw the condition of the heat shroud around the turbo.  The heat discoloring of the shroud indicates the operator is running it WAY too hot!  I'm guessing he's thinking he's running lean of peak when in reality he's running it right at peak.  that would explain burned up pistons and exhaust valves.

Running extra fuel through a turbocharged engine to keep the temps down is actually cheaper than replacing cylinders, etc.  When it comes to peace of mind regarding how healthy your engine is on a single...  it's PRICELESS!!!
"Me and Earl was haulin' chickens / On a flatbed outta Wiggins..."

Wolf Creek Pass, by CW McCall

Offline Mike

  • Supreme Overlord
  • Alpha Rooster
  • *****
  • Posts: 3376
Re: Request: Aircraft Piston Engines 101
« Reply #10 on: November 22, 2007, 05:39:15 PM »
Hey Frank, to get back to the topic:

Here is a picture of a Cessna 172. (the closest I could find to a Cardinal)


Dear IRS: Please cancel my subscription.

Offline Mike

  • Supreme Overlord
  • Alpha Rooster
  • *****
  • Posts: 3376
Re: Request: Aircraft Piston Engines 101
« Reply #11 on: November 22, 2007, 05:56:44 PM »
Let's just talk about what's in the little Cessnas for now:

A Lycoming engine is what they call "boxer motor" in Europe. The Americans call it horizontally opposed cylinders.
For example a "O-360" means opposed cylinders, 360 cubic inches.
an "IO-360" would be an injected engine w/ opposed cyl. . . .
helicopters usually run HIO-360's and so on and so on . . . .

they are basically tractor engines from the 50's. Huge, but keep running.

Two sparkplugs in each cylinder, each plug runs of a different magneto.
(one magneto runs the top two plugs on one side and the bottom two plugs on the other side)
That helps the fuel burn better when they are both working and puts in redundnancy in case one magneto fails

They also have two mechanical vlaves in each cylinder. And, yes, they need to be checked and re-set periodically.

Each cylinder head can be removed and repaired individually. It's a very simple engine once you take a close look.
There is no cylinder block. Since the engine is aircooled (needs fins around each one of them) you don't need one and this way you can fix
individual cylinders pistons and rings without removing and replacing the whole engine.

Lubrication is what they call a dry sump I believe. The oil reservoir is in the bottom (square block, you can see it on the picture)
and the oil gets sucked to the top, runs trough the cams and so on until it drips back into the reservoir.
Yes, most have oil coolers, but the cylinders are aircooled.

The reason why the engine shook when it was shut down is a combination of the prop directly running of the driveshaft
and this engine having a huge amount of cubic inches as compared to a European car.

Most of them have only one fuel nozzle per cylinder.

Did that answer all your questions?  ::wave::


Dear IRS: Please cancel my subscription.

Offline Mike

  • Supreme Overlord
  • Alpha Rooster
  • *****
  • Posts: 3376
Re: Request: Aircraft Piston Engines 101
« Reply #12 on: November 22, 2007, 06:00:30 PM »
the Tiger has two cylinders removed (at least on the left side) and on the top right you see the oil-cooler.
in the front, underneath the ring-gear on the prop, you can see the starter


Dear IRS: Please cancel my subscription.

Offline Frank N. O.

  • Alpha Rooster
  • *****
  • Posts: 2446
  • Spin It!
Re: Request: Aircraft Piston Engines 101
« Reply #13 on: November 22, 2007, 11:42:10 PM »
Wow, great info there Mike, and what a cool illustration picture |:)\
It was also ok it wasn't a Cardinal since it was generally about piston engines, the note about the Cardinal was just for the shaking, but I'd thought it was because a boxer-engines cylinder's aren't exactly parallel seen from above so at low rpm it might do that.

I didn't know the classic Lycoming was based on a tractor engine, that almost completes the circle with Preston Tucker's classic Tucker Torpedo which had it's rear-mounted air-cooled flat-6 from a helicopter. The Dodge Viper V10 engine was of course derived from a Dodge pick-up engine and the Y2K Jet Bike uses a Rolls Royce Allison 250-series gasturbine from a helicopter. I've read that several ultra-lights use Mazda Wankel rotary engines and then of course there was the PFM, 'nuff said.

Frank
"When once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return."
— Leonardo da Vinci

Offline Rooster Cruiser

  • Alpha Rooster
  • *****
  • Posts: 1996
  • Retired Chicken Hauler
Re: Request: Aircraft Piston Engines 101
« Reply #14 on: November 23, 2007, 03:11:58 AM »
If memory serves me, the flat, horizontally opposed, air cooled piston engine was originally designed for aircraft propulsion and patented by Dr Porsche around 1927.  The design proved so reliable compared to other engine designs of the day, that when Herr Hitler decreed Germany would produce a "People's Car" or Volkswagon, the engineers selected Dr Porsche's design and modified it for automotive use.  This was also due to the design's relative light weight and ease of maintenance as well as its reliability.
"Me and Earl was haulin' chickens / On a flatbed outta Wiggins..."

Wolf Creek Pass, by CW McCall