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R.P.M Technical Question


joe n suzanne
03-08-2005, 06:14 PM
Ok, I am confused on the revolution per minute (RPM). I understand that if the tach is at lets say 1,000 rpm, the engine is turning 1,000 rpm. My confusion is this, Since the engine is turning 1,000 rpm, how many times is there a spark event at a steady 1,000 rpm's?

Considering I have the 3800 Series II in my 98 Park Avenue, and it is a V-6, how many times does it spark lets say at a steady 1,000 rpm? I am very familiar with 2 cycle engines like weedeaters, that fire a spark every revolution, but the 4 cycle engine fires every other revolution. So is it safe to say that it fires a spark 500 times at a steady 1,000 rpm?

I am just curious and trying to learn something.
Joe

tman
03-08-2005, 07:08 PM
Very interesting, lets at one cylinder for simplicity's sake. The piston must move up and down 2 times to complete a combustion cycle, meaning 2 revolutions of the engine. the spark plug fired once.it's a fraction of 1/2 (SP firing/Revolutions).

Therefore, you are correct in 500 times PER CYLINDER. on a v6, your looking at 3000 firings per minute on all cylinders.

volkerc
03-09-2005, 06:23 AM
Ok, I am confused on the revolution per minute (RPM). I understand that if the tach is at lets say 1,000 rpm, the engine is turning 1,000 rpm. My confusion is this, Since the engine is turning 1,000 rpm, how many times is there a spark event at a steady 1,000 rpm's?

Considering I have the 3800 Series II in my 98 Park Avenue, and it is a V-6, how many times does it spark lets say at a steady 1,000 rpm? I am very familiar with 2 cycle engines like weedeaters, that fire a spark every revolution, but the 4 cycle engine fires every other revolution. So is it safe to say that it fires a spark 500 times at a steady 1,000 rpm?

I am just curious and trying to learn something.
Joe


check out this link...:

http://www.keveney.com/otto.html

joe n suzanne
03-09-2005, 06:26 AM
Thank you both for the great info and also the cool link. Now I am clear on the subject.
Joe

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