Kawi2strokes.com Forum

I haven't delved into crank phasing, but you have to look at the multi cylinder as just three singles that are connected. So if each crank/rod/piston assy is balanced, then it's not a problem. The 90/90/90 gives more overlap on the power strokes, with a bit of a "rest" for the tire for 180 degrees.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

I don't think it's you who is missing something. The guy who wrote the web page seems (to me) to be saying that grouping the firings into 180 degrees, with the right one firing first, somehow reduces crank stress and increases horsepower. Let's hope he keeps us updated with his progress.

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If it surges, that's normal, upshift.

It's been too many years since I took that night school course on high performance engine building (4 stroke) but the guy did cover the firing angles of the cranks, the V6 being a bit of a bugger to balance compared to the 4 cyl and 8 cyl having a natural opposing cylinder to minimize crank stress and balanced as a whole...
I've never looked at V6 crank since taking the course but 2 of the lobes were separated by a few degrees, instead of being equally separated.
To be honest, I can't remember the reason and I don't have my notes any longer to recall why. It was all about minimizing crank torque deflections then anything else I suppose...

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http://kawatriple.com/wtf/

If I remember right, a 60 degree V-6 has better natural balance than a 90 degree V-6. Because GM wanted to use a small block V-8 design with two cylinders lopped off to save designing an engine from scratch, they were stuck with the 90 degree configuration, so they split the journals to improve the balance, quite possibly for the reason you gave.

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If it surges, that's normal, upshift.

Sure looks like a big advertisement to me. He forgot to mention how in a stock frame you could have a widowmaker that wheelies through all the gears and goes 300 plus miles an hour.

why would any one put all that effort in, very body knows Chris Ritchi make the most powerfull triple engines, he could get one from him turn key.

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If Satan had a bike and fed it cats it would sound just like my bike.

Henry, you are such a little tease!

Jim, There were even fire and odd fire, The early ones had both rods from each pair of cyls on a single journal, the odd fire. Rougher running at idle and low speeds. The even fire had the split journals. Smoother running at low speeds.

Interesting read: http://en.wikipedia.org/wiki/General_Mo ... _V6_engine

Don

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Don

"This is not our first custom H2 project, we built a 860cc with altered crank firing order in 1989 and won the open class 89,90 & 91 against 1500cc harleys & 4 cyl jap bikes."

Maybe they know more than they are being given credit for?

I don't see what is ambiguous about this. A win is a win is a win, ask Tim Tebow

The crank phasing sounds like the same principal used in the 'big bang' 500 moto GP bikes where the uneven power delivery allows time for the tyre to gain traction. The moto GP guy's probably took the idea from dirt riders anyway, I remember reading years before about moto cross sidecars using two stoke triples were at quite a disadvantage even though they were making the bigger HP. The regular and often power pulses just caused the tyre to spin up compared to the big slower revving 4 stroke XS twins which had plenty of 'resting' time between the power pulses which allowed time for the tyre to hook up. This would be an even bigger plus for dirt hill climbing wouldn't it?