Author Topic: Timing  (Read 3883 times)

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Re: Timing
« Reply #8 on: March 04, 2010, 13:38:33 pm »
Most engine's  intake valve opens before top dead center.  The exhaust valve opens well before bottom dead center.  There is a period of time (overlap) when both valves are open.  My thoughts are to shoten the duration on the cam and take advantage of a more complete burn.  Also I would expect the engine make more torque at a lower rpm and would not need to rpm as high.  You would think there would be a less chance of a backfire as well. 

I'm sure  mr. Meyers had a reason for using an aircooled engine, can anyone help me understand  if there was a reason other than cost?

Hi Jim
Welcome to ionizationx!

It is known that in a 4 stroke cycle the inlet valve(s) open twice.
This is a fenomenon not many people know.
If you use a 1 cylinder powergenerator, you will have a waist spark and that means that in one complete cycle the sparkplug fires twice.

Both points above give lots of trouble.
It goes well on the powerstroke, but it goes totally wrong on the waist stroke where the piston pushes the gasses into the outlet.

It might be an option to adjust the valvetiming, however, dont forget that an engine is an airpump.
You must have sertain amount of air flowing otherwise you loose power.

Steve