Triple engine uneven idle

[Triple Trouble]

I think you are confusing the firing event with the otto cycle. Look at each individual cylinder as a separate entity and you will see that it fires every 720 degrees.

 

[idk]

This is where the power strokes go on 3, 4, 6, 8, & 12 cylinder engines. Because these are 4 stroke engines there is a 720 degree cycle. Each suck, squeeze, bang, and blow take 180 degrees. The V8 is a Chevy, the V12 is a Mercedes. Other makes and engines will vary - even engines by the same manufacturer.

In addition to the overlap of power strokes, 3, 6, and 12 cylinder configurations have a different feel because of the fact that all the pistons reach the end of their stroke differently in relation to each other than 4 and 8 cylinder engines.

There are, of course, many variations. I had a Honda 2 cylinder car with a firing order of both at the same time. Triumph makes 2 cylinder engines with offset cranks. etc.

 

[Claviger]

Exactly as I thought, there IS a gap in a 3 cylinder motor, apparently my degreeing is fubar on my chart though

****in crazy ass engines i'll tell ya.

Forgot that each portion of the otto cycle is 180 regardless of crank design or cylinder count. Now it makes sense that there are three small gaps per cycle instead of one larger one per revolution.

 

[zimtuff]

Exactly as I thought, there IS a gap in a 3 cylinder motor, .

Yes ,there is a good article on wiki about it. I come across it when i was looking at a 5cyl toyota diesel. Engine builders use all sorts of trickery to make them run smooth but you cant beat engines where the number of cylinders are divisble by 4