To prove I'm no mechanic..

I was doing OK until my know all mate came round at q32,it went down hill from there.a dismal 72%i'm afraid.:(:(:([:(!]

Trev

back to my "rootes"
 
Case in point, Tim 82%, Martin 86% two of the most skilled mechies on the site. Me - inept, hamfisted bodger 88%. The true craftsmen aren't necessarily quiz whizzes but just get on with it. Go woolfy, no offence reaultvation :I
 
I was always led to believe that atmospheric pressure was the same what ever the suface area it was on and i surpose air will enter an open valve into a cylinder under atmospheric pressure wether a piston is pulling it in or not but i stand to be corrected,maybe i haven't read the questions properly[?][?][?]

back to my "rootes"
 
That's correct, that is why you need to turbo or supercharge an engine to force more air/fuel in, you can only open the valves so far to allow the atmosphere to do its stuff on a normally aspirated lump. There is in fact no such thing as suction :I
 
What happened to 'Suck, Squeeze, Bang, Blow' [?]

Yes, atmospheric pressure is the same on any surface, slightly trick question ;)
 
Right - here goes.

Suck (verb transitive) - to draw up or render by suction.

Sucker (noun) - a device that ... draws water etc. by suction, such as a pump piston.

Suction (noun) - the act or power of sucking or of drawing or adhesion by reducing the pressure of air :p

Therefore, they can both be right. The piston sucks air by reducing pressure in the cylinder and atmospheric pressure pushes air in through the valve as it becomes higher pressure than that in the cylinder [?]

I answered suction from the piston, using the 'suck squeeze bang blow' cycle I was taught in physics (we didn't do film studies and I dropped biology at 'o' level) [}:)]

P.S. Panky, no offence taken, I am not a mechanic and will need help when I get to the greasy bits of my Renault, particularly the fuel injection.
 
out of the 4 possible answers to the last question 3 are correct.
gravity- air has weight (the air in a 10ft sq room weighs 80lb)even more so when mixed with petrol (7lb a gallon), so gravity does help induce mixture in.
suction- the piston traveling downwards will creates a vacuum which causes suction.
atmospheric pressure- as renaultvation says, the descending piston creates a change in volume which causes a pressure drop which a/p will rush to fill. (this is the answer they wanted).
sneaks [V]

"you were only supposed to blow the bloody doors off"
 
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