Think you know two-stroke engines?

[1Alpha1]

Take this quiz and find out just how much you do know:

http://quizzes.autoversed.com/quiz/...b23bc&sg_uid=eee8fae4326f41c0aaca129e86cb23bc

 

[Bobby Kirbos]

24/30 = 80%

I passed.

 

[1Alpha1]

Your diploma is in the mail.

 

[Canyon Angler]

"Small four-stroke engines commonly have compression ratios of 12-to-1"???

Really? My 1969 Pontiac 400 had a compression ratio of 10.75-to-1 and required high-test gas...I always thought that was fairly "high" compression, and that small 4-stroke engines would be less than that, not more...

 

[Sepia]

Gasoline type ignition? 32:1 typical oil ratio? Both ports open at start of stroke?

I guess I need to go back to school and brush up

 

[Bobby Kirbos]

I'm still trying to figure out how the oil gets introduced in the carburetor .

 

[ironman_gq]

Mixing UK terminology in there really mucks up the questions. Pretty sure this quiz was written by someone with no knowledge of engines reading notes that were submitted by a months worth of "caller number 9" people on the local radio.

 

[ericm979]

100% (because I know UK gearhead slang) but a lot of the questions are dumb. The both ports open at the start of the cycle- they must mean the start of the intake event, where on piston port engines the exhaust is often still open. But that's not a requirement.

Ok guys, another question: what's the engine in the picture?

 

[Sepia]

https://en.wikipedia.org/wiki/Saab_two-stroke

 

[Cope1024]

23/30.

 

[JimM]

Your diploma is in the mail.

How did ‘you’ do?

 

[Mustang71]

The compression ones are odd. I don't think the push mower is running at 12:1 and I don't think the stihl is running at 6:1. The push mower gets 87 octane and the saws get 91 I must be doing it wrong.

 

[tomdcoker]

18/ 30. Summer school here I come.

 

[1Alpha1]

How did ‘you’ do?

Don't know why you'd care, but whatever........

 

[CR888]

26/30. Yeah the oil originating in the carburetor was a tricky one. The multiple choice was something like: sump, carb or neither. I selected neither & got it wrong.

 

[spyder62]

Cmon guys, need some more answers before I take the test

 

[smokey7]

Goofy questions but fun non the less. Didnt know bigger 2 cycles were more efficient. I got it right but didnt know for sure. I found it funny required oil ratio was 4 oz to gallon. Thsts what i do so Thats good lol

 

[Little Al]

I'm still trying to figure out how the oil gets introduced in the carburetor .

Same way as the gas as it's mixed with it

 

[Canyon Angler]

Overall, the questions seemed to be either ridiculously easy ("A two-stroke engine operates on how many strokes?") or puzzlingly vague... like all the words were there, but were mixed up in a bingo cage before the question was phrased.

Plus, for some reason (I'm guessing because I use a Mac), I got no score at the end.

 

[ironman_gq]

The compression ones are odd. I don't think the push mower is running at 12:1 and I don't think the stihl is running at 6:1. The push mower gets 87 octane and the saws get 91 I must be doing it wrong.

Most are in the 6-8:1 on 2 strokes, older flathead 4-strokes were about the same and most modern 4 strokes are in the 8-10:1 range. Only way they're seeing that kind of ratio is if they're taking full cylinder volume to compressed volume which is very inaccurate on a 2-stroke. The true ratio is the swept ratio, it starts measuring at the top of the exhaust port.