Ok motor heads, time to educate me

[Mark XB12r]

So back story to my question... I was trying to explain the Buell motor firing sequence, and I realised that i actually didnt know.

I tryed searching but couldnt find it.

Ok for the question, Do the cylenders fire oposite of each other. Such as, Is the back cylender on its compression stroke as the front is on exaust.

The other option which is what i was thinking was the case until i started thinking about it, was that they fired on right after the other. Each cylender in the same cycle just a split second behind the other.

I have no use for this info other than just adding to my my vault of useless info

Ok motor heads, time to educate me...

Thanks, Mark

 

[lotusexcelle]

http://www.wildwestcycle.com/f_firing.html Explains the Harley system pretty well.

 

[snrusnak]

I'm pretty sure the power stroke(where the spark plug fires) of each cylinder is 180 degrees apart(degrees of crankshaft rotation). So it would be opposite. I'm not positive so let someone else who is more familiar with this engine confirm...

 

[lotusexcelle]

Also it should be noted that the Buell version of the Harley design actually uses dragon breath instead of gasoline. It gets converted in-frame. (at least that is what is sounds like)

 

[Mark XB12r]

Since its a single crank pin, 180 is impossible but I know what your saying... Thanks for the replys, now to do some more reading

 

[Mark XB12r]

The front cylinder fires, pushing the piston down on a power stroke, spinning the crank. The rear piston is already 45 degrees down its bore on an intake stroke, being pulled by the crank, sucking in a load of fuel. Make sure you can mentally visualize this or you're gonna get lost.


This was all i needed from lotusexcell's link. Thank you! rep poing givin for the help

Also it should be noted that the Buell version of the Harley design actually uses dragon breath instead of gasoline. It gets converted in-frame. (at least that is what is sounds like)

Hahaha! badddazz!

 

[d_adams]

Copy/paste from a random hd site. I don't know which actually fires first though. I think it's the front cylinder based on the crank rotation.

The difference in the Harley engine is that the crankshaft has only one pin, and both pistons connect to it. This design, combined with the V arrangement of the cylinders, means that the pistons cannot fire at even intervals. Instead of one piston firing every 360 degrees, a Harley engine goes like this:

A piston fires.
The next piston fires at 315 degrees.
There is a 405-degree gap.
A piston fires.
The next piston fires at 315 degrees.
There is a 405-degree gap.

 

[Mark XB12r]

im not concerened which fires first, im not using it for technical knowledge, just general info... opposite is the answer i was looking for

Thanks D...

 

[Mark XB12r]

Oh and i know its Cylinders not cylenders... sometimes i dont proof read

 

[snrusnak]

hmmm....I guess I don't know what I'm talking about lol.

 

[Mark XB12r]

Ahhhh its fine, common mistake, We all get to learn from these questions.

you want your mind blown, look into how rotory (wenkle) engines work, now thats nutty

 

[snrusnak]

That's the thing, I'm actually pretty knowledgeable on general mechanics(or so I thought) lol. Rotory engines are great but they just aren't common enough.

 

[Zeroflat24]

Also it should be noted that the Buell version of the Harley design actually uses dragon breath instead of gasoline. It gets converted in-frame. (at least that is what is sounds like)

ironically my buddy who is a buell tech told me they actually used molds of chuck norris' fists for the pistons.

 

[Mark XB12r]

^^^[up]

 

[Alfatango1]

you want your mind blown, look into how rotory (wenkle) engines work, now thats nutty

Actully the Wankle Rotary engine is a work of utter simplicity. Great design. I've had a number of RX's and they were fun, fun rides.

 

[snrusnak]

^but the fuel mileage on a rotary engine compared to a piston engine is horrid. It's all relative though, they produce more power per volume. Same with a 2 stroke, they use roughly twice as much fuel, but produce nearly twice the power per volume. They all accomplish the same thing in a different way...

 

[Iamarchangel]

 

[mtnmason]

I read in some motorcycle publication about how the dirt tracker harley guys back in the day would set the timing so that both piston fired simultaneously essentially making the motor act like a big single, but after seeing that I dont see how it would be possible.

 

[Alfatango1]

but the fuel mileage on a rotary engine compared to a piston engine is horrid.

Absolutely true, longevity can be a problem too. Apex seals can get damaged and poof! There goes your engine.

 

[twobuells]

mtnmason they were called twingles and used on the loose tracks. You needed to change the cam timing also. The ideal was to get the power stroke part of crank rotation out of the way so the tire would have more time to hook up.