Need Technical Explanation!

[sTuDeNt]

Guys can some one explain to me in great details how timing on internal combustion engine works and its principles please. Shame to say but i know nothing about it... :oops:

I would like to know more!

PLEASE HELP!

PS

Prefferably explain how it works on carb engines, cuz i sort of have rough idea about ECU engines!

Cheers!

[j1400]

www.howstuffworks.com

should be something in there with animation, makes it much easier when you can see it

[Stuart]

timing can be 2 things on, cam timing (but thats a bit complex and i wont explain it) and the second is ignition timing (and technically a third which is injection timing but thats not present with carbs)

ignition timing is the "time" or moment that the spark is created in the engine to start the burn of A/F

fuel takes time to burn so you can just set the spark at the top of the compression stroke and expect best perfroamnce and emissions. you have to advance it eg set the spark before the piston hits TDC.

as a general ruel of thumb the air fuel mix takes about 40 degrees of crank movement to burn. so you want to set the timing up to spark consistently advanced at increased engine speeds to maintina a full burn.

go too advanced and you get the fuel burning to peak pressure before tdc and that can cause detonation and lots of engine damage.

thats very very brief overview of ign timing