C172 Magneto question

[Lead Sled]

Fuel, air and spark. That is all you need to make a piston engine run.

Wrong. You forgot MONEY.

'Sled

 

[Pedro]

Aha! His suspicion was right!!!... it's the prop that drives the magnetos!

Or is that magnetoes? Tomatoes Tomatos; Potatos Potatoes? Dang. Anyway.. I need to get back to my wine.

No, the prop doesn't drive the magnetos, the engine does, and also drives the prop. If the propstops turning is an indication that the engine stopped turning, which is alsoavery goodindication that the magnetos stopped turning.

Back to your wine!

 

[erj-145mech]

Aha! His suspicion was right!!!... it's the prop that drives the magnetos!

The prop is just a cooling device, it keeps the nut behind the yoke cool.

Want proof? When the prop stops, watch the nut sweat.

 

[Geronimo4497]

Wrong. You forgot MONEY.

'Sled

How foolish of me. Money first, then all of those thing.

 

[bertengineer]

I was thinking backwards, I was thinking alternator. Just messed up my logic. Whats the point of magnetos if you dont have an engine working anyways. Thanks for the good replies, that cleared it up. and yours too bugchaser.

This really could have been answered if he had opened up the book that came with the private pilot package, and he is an instrument student? Good luck with that instructor.

 

[Crossky]

No, the prop doesn't drive the magnetos, the engine does, and also drives the prop. If the propstops turning is an indication that the engine stopped turning, which is alsoavery goodindication that the magnetos stopped turning.

Back to your wine!

Of course he knew that, you couldn't see that in his smarta$$ remark? Though, in a windmilling, no power situation airborne, the prop does drive the engine and the thus the magnetos, until you get slow enough for the prop to stop. That's the situation he and the original poster are referencing.

Peace.

 

[FN FAL]

There is no "I" in "Magneto"...it's all in the "O"!

 

[NYCPilot]

Here's some trivial information about your engine too.

Engine designations might be something like IO-360, O-320 and so on. You might have wondered what these numbers and letters represented.

I = Injected
O = Opposed (as in horizontally opposed cylinders)
360 = 360 cubic inch displacement


Also, if you take half that figure, you'll get an approximation of the HP of the engine.

360 = 180 HP

320 = 160 HP

 

[WMUchickenhawk]

Here's some trivial information about your engine too.

Engine designations might be something like IO-360, O-320 and so on. You might have wondered what these numbers and letters represented.

I = Injected
O = Opposed (as in horizontally opposed cylinders)
360 = 360 cubic inch displacement


Also, if you take half that figure, you'll get an approximation of the HP of the engine.

360 = 180 HP

320 = 160 HP

Its a textron Lycoming IO-360-L2A, but it also says the hp is 160.

 

[Geronimo4497]

I take it that you are flying a late 1990s 172 then? The early new production 172s had a IO-360 engine that was derated to 160HP. Kind of stupid, but whatever.


What is the max RPM in your airplane? I ask because some OEMs limited the HP by derating the max engine RPM to get the desired HP.