AGK Question (Magneto Failure)

[CptWood]

I'm currently studying CPL AGK and have come across a question that has stumped me and alot of other pilots I have asked. The question is:

"If you have a magneto failure will this cause the engine to run hotter or cooler"

Naturally I assumed that if there is only one spark in the cylinder now, it will cause some fuel to not be burnt which can then evapourate and cool the engine, however the asnwer is hotter. Some people have answered hotter but are unable to give a descent explanation as to why. If someone could give me a more detailed explanation as too why this is the case that would be much appreciated!

Thanks

Lachy

[As I See It]

Interesting that the answer is hotter, as a fouled plug will cause the affected cylinder to run cooler. Using this example, a total magneto loss will cause the engine to loose power and run cooler due to incomplete combustion. The same reason the RPM drops when carrying out a mag check.

This is As I See It

however, I have been proven wrong before, but in that instance my Dad Knew the answer:D

[vincent van gogh]

hello,

check this link
http://www.cafefoundation.org/aprs/ignition1.pdf

scroll down to page 4 Dual ignition operation
this explains a bit more

regards Vincent

[CptWood]

Hey thanks for the link, very helpful indeed. I never would have guessed that to be the reason! You learn something new everyday. Thanks again


Lachy

[As I See It]

I suppose it's how you define engine running hotter, CHT or EGT?

[GotTheTshirt]

As I see it - yes thats the question CHT or EGT

Most light aircraft have CHT as basic and EGT is often an add on.

Given the reason that the article gives is that the fuel is burning in the exhaust then it is possible that the CHT will decrease as less combustion is taking place in the cylinder.

Anyway if you are taking exams then you only need the answer that the exam is looking for ;)