Engine Quiz

[CobyRupert]

Got 29/30.
What were the zingers?

I got "What causes engine knock?" question wrong.

I saw the choices as "Wrong spark plug" or "Low engine oil"? I thought wrong spark plug might cause pre-detonation, i.e. knock / ping, but I thought that was more a function of gas octane and timing?
Low oil, which, if low enough, definitely can cause knock, right before it seizes. Right?

Why was I was wrong?

 

[Mace Canute]

30/30. Easy peasy.

 

[Mace Canute]

Got 29/30.
What were the zingers?

I got "What causes engine knock?" question wrong.

I saw the choices as "Wrong spark plug" or "Low engine oil"? I thought wrong spark plug might cause pre-detonation, i.e. knock / ping, but I thought that was more a function of gas octane and timing?
Low oil, which, if low enough, definitely can cause knock, right before it seizes. Right?

Why was I was wrong?

Spark plugs have "heat ranges" which basically means the distance heat travels from the tip of the plug on a hotter plug is farther than the distance heat travels from the tip of the plug on a colder plug, the heat being from the fuel combustion of course. More here NGK Spark Plugs

When the tip becomes too hot it will prematurely ignite the air/fuel mixture and the resulting"explosion" happens too early in the compression stroke and the pressure wave hits the cylinder/combustion chamber hard enough to make the dreaded pinging noise.

 

[Mace Canute]

Double post.

 

[frugalangler]

I liked the 'Otto' zinger, 30/30 for me!

 

[2LaneCruzer]

I gave up after two questions; it was loading so slowly I figured they were recording my life history along with my bank account and IRS filings.

 

[the old grind]

30/30 and no trick questions to befuddle .. for once. :laughing:

Easy-peasy is right, but I'd already drank my OJ this morning and was nearly awake.

Is there a level 2?

 

[LouNY]

30-30, I should go clean my old one also.

 

[jaxs]

I got 30/30. What were the "zingers"? I'm not bragging, I'm just wondering if all the tests have the same questions.

SimS

Amusing zingers were different or missing altogether in some tests. They kept changing the questions,otherwise I'm pretty sure I could have got 30/30 but I just quit after 3 tries and posted my best 1 out of 3. I might try again tonight. If I manage 30/30 I might swagger but no way would I brag.:number1:

 

[ning]

Not a mechanic but I've been known to fix stuff; 30/30.

Only one that gave me a pause was the "external combustion engine" being the steam engine. I knew that "hydroponic engine" gobbledygook, but I wasn't sure about the 3rd thing existing or not. However I can imagine running a steam engine by lighting a fire under a closed water system - it could work - and though the steam engines I'm more familiar with (steam locomotives) have an "enclosed" firebox, it doesn't have to be closed and you can open it up any time to feed the fire - thus it's not really internal.
Of course in a similar way you can consider the Otto cycle engine to be external because you open it to let is suck fuel, but during the actual combustion cycle it's quite well closed (thus having measurable compression).

For the pinging one - I figured wrong spark plug may fire too early, which would be similar to compression-charge detonation. Also could fire too late/not at all? But that wouldn't be a ping; regardless the other answers weren't a good fit.

My guess is that those of you at less than 30 accidentally clicked the wrong box.