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Questions tagged [piston-engine]

Piston (reciprocating) aircraft engines are internal combustion engines, similar to the type found in most automobiles. They are typically gasoline powered.

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2answers
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Why does the lack of a magneto affect engine RPM?

So I don't have my pilots licence, but I was part of the Australian Air Force Cadets for nearly 8 years (wonderful organisation). During this time I went on a number of flights in Cessna 172's and ...
6
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1answer
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Where to find Tach hour and clock hour equivalence rpm?

There is a revolution counter built into the face of the Tachometer in most piston powered GA planes. This counter is calibrated in hours. Most planes also have a Hobbs meter, which is a clock. ...
11
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2answers
42k views

What is the difference between SMOH and SFOH?

When looking at aircraft for purchase online, a lot of acronyms are used. In particular, the SMOH and SFOH acronyms are thrown around a lot for used aircraft. What are the differences between these ...
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3answers
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What may be the cause of hot start problems in a Lycoming fuel injected engine?

Cherokee Six, 32-300 1969. Lycoming engine is fuel injected with 450 SMOH. Cold starts are easy: 1/2" throttle, full rich, fuel pump on and hit starter after fuel flow starts. Runs great once running. ...
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2answers
4k views

What was the first aircraft that could fly inverted?

I'm taking a guess and assuming the Wright Flyer was incapable of flying upside down. I'm just guessing it probably lacked the power... ;) So what was the first plane that could fly inverted for a ...
16
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4answers
19k views

What are the advantages/disadvantages of diesel/Jet A-1 piston engine?

Some GA aircraft, notably the DA40/DA42, are equipped with piston engines that use Jet A-1 and/or automotive-grade diesel instead of aviation gas (avgas). An example of such engine is the Austro ...
32
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14answers
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Why don't small planes use turbine (turboprop) engines?

Turboprop engines are more fuel efficient1, lighter for the same power, mechanically simpler and consequently more reliable. They are also slightly easier to operate (no need to fiddle with mixture) ...
13
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1answer
9k views

Why does manifold pressure increase when you turn on carb heat?

So everyone knows that carb heat decreases engine performance. Yet when we check the heat during run-up, the manifold pressure increases. Why is that? Shouldn't adding carb heat cause the intake air ...
12
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2answers
871 views

Is the Soloy Dual Pac recognised as two engines or one engine?

The Soloy Dual Pac apparently allows two engines to rotate one propeller -- here's a picture of it on an Otter: Is this recognised as a centreline thrust twin engine aircraft, a "standard" twin ...
20
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5answers
38k views

Why are Inline Engines more commonly used than Radial Engines?

Back in the early days of aviation radial engines were very popular, it seemed like all of the big planes of the 20s, 30s and early 40s used them. But some time during WWII (or so it seems to me) ...
16
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4answers
6k views

When to reduce power on takeoff (Cessna 182 or similar)?

There are two sides I've heard when taking off in a Cessna 182 or other small airplane with a normally aspirated engine driving a constant speed propeller: As soon as your wheels are off the ...
5
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1answer
1k views

Should you sump fuel tanks when the fuel system is below freezing?

I recently saw an argument in a forum I frequent that sumping the tanks when the system was below freezing was a bad idea, as you can't drain solid ice from the fuel system, and there is a chance that ...
13
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6answers
20k views

Why are propeller airplanes still made?

Airplanes with propellers were invented a long time ago. After that, jet engines came into existence. My question is: why do we still have propeller engines? The reasons I can think of are: They are ...
5
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2answers
7k views

What are the differences between Lycoming and Continental engine designs?

Inspired by a discussion in chat. Most GA piston singles are powered by either Lycoming or Continental engines. The engine designs used by both manufacturers are broadly similar (4-cycle, ...
5
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1answer
616 views

What FAA requirements exist for electronic ignition systems on piston engines?

Most GA piston aircraft still use dual magnetos for their ignition system, but there are some STC kits available to add electronic ignition to common piston engines, and new aircraft often come with ...
14
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3answers
5k views

Rotax engines have no mixture control, how do they handle less dense air?

Rotax engines have no mixture control, yet they don't seem to have any more problems than other engines at altitude. How do they handle the lower air density in order to not get a too rich a mixture?
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3answers
10k views

Why are updraft carburetors standard in aviation?

My only detailed experience with carburetors is in aircraft. I'm pretty familiar with the principles behind float-type carbs, but I recently saw a schematic for a "downdraft carburetor" with a choke ...
9
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2answers
1k views

What can I do if my carb-heat cable breaks in-flight?

If I'm flying in conditions that are conducive to carburetor icing, and my carb-heat cable becomes in-operable, is there anything I can do to prevent engine failure if my carburetor starts icing up? ...
21
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3answers
10k views

Why are propeller engines uncommon on airliners?

My experience in aviation is essentially zero, but looking at Wikipedia it seems like the Tu-95 Bear offers high subsonic speed and extreme range. I assume that turboprop engines are more fuel ...
8
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2answers
4k views

Why/How does a “Powerflow” exhaust increase horsepower?

I've seen airplanes (typically Cessna 172s) with a "Powerflow" exhaust system and then claim to get several more horsepower, resulting in faster cruise speeds. How does a Powerflow exhaust work, and ...
9
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1answer
2k views

Is there an FAA ruling about the airworthiness of piston engines with less than 60 on the compression test?

We've been having some discussions around if there was a specific ruling from the FAA that explicitly said that if a cylinder was showing less than 60 on the compression test, the FAA deemed it ...
6
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2answers
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CO-meter indicates 10ppm of Carbon Monoxide when I turn on Cabin heat - should I be concerned?

Our Cessna 172P is equipped with a digital CO-meter rather than the traditional Quantum eye carbon monoxide detector. Today I was flying along in winter conditions, and naturally used cabin heat. ...
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2answers
4k views

To a pilot, does turbocharging differ from supercharging?

When it comes to operating an aircraft, what are the practical differences between a turbocharged engine and a supercharged engine? I'm aware of the mechanics - turbochargers being exhaust-driven, ...
27
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7answers
6k views

How can reducing power too quickly on a piston engine damage it?

In many places, it's been stated that you should reduce power slowly to prevent engine damage. Depending on who you talk to, some say you should reduce the manifold pressure by 1 inch per minute, ...
20
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6answers
9k views

Why should some piston engines not be run lean of peak?

Leaving aside the claimed pros and cons of lean-of-peak (LOP) vs. rich-of-peak (ROP), the C172S Lycoming IO-360-L2A handbook I have says "Continuous operation at mixture settings lean of peak EGT is ...
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1answer
1k views

Experiences with LiFePO4 starter batteries in light aircraft or motorized gliders? [closed]

I am interested in real-life experiences to do with using LiFePO4 batteries in light aircraft and motorized gliders compared to standard PbA ones. LiFePO4 seem to be a very attractive alternative to ...
9
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3answers
1k views

How do turbochargers aid engine performance as density altitude increases?

How do turbochargers improve engine performance at high altitudes / density altitudes? Could you also address how this benefit could become a liability at low density altitudes, for example when the ...
34
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2answers
9k views

How often should an engine be run, to stay mechanically sound?

It's winter time and many light aircraft are sitting idle. This can be detrimental to an engine's health. What is a good rule of thumb for how often a piston engine should be exercised, and for how ...
20
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2answers
6k views

When is pre-heating a piston engine important, and how does one pre-heat correctly?

As temperatures here in New York plunge toward (and below) freezing it's time for those of us without nice heated hangars to start thinking about pre-heating our aircraft before we turn the key. ...
10
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1answer
1k views

What should I look for / check during an oil change?

Piston aircraft engines require regular oil changes, and at least in the US it's something the FARs allow an owner with a private pilot certificate to do. What are some of the things I should look ...
18
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3answers
31k views

How does the mixture of an engine affect the engine's operation?

I know that in most piston aircraft that there is a mixture control for the engine. My question is, how does the mixture control affect the engine's operation and what type of situations dictate a ...