Crazy Ramblings?: Twinned Four

You know, it's just one of those funky thoughts that crosses your mind while you're crawling around the ground changing the oil in the cars and the bikes......

What potential ramifications could be concieved from "disabling" cylinders on a motorcycle. Others here have mentioned that they don't imagine any permanent damage from running a little while on a bike that's missing. What if you were to construct a bypass valve for the intake (eliminating vacuum within certain carbs) and switch or relay the ground for cylinders 2 and 4, for example?

You'd lose a lot of power, obviously...possibly generate more heat in specific areas if the overal temperature doesn't necessarily increase. But, otherwise............?

you would put strain on the crankcase i'd imagine. I'm not really fluent with these engines but i imagine that they dont use counter weights to save weight and so they use the cycles of each piston to counter the turning forces. if you knock 2 cylinders out it ride really rough. Chryslers 300C uses this technique but it does so be releasing combustion pressure on strategic points in the firing order as well as a balanced crank. i'm sure someone will click in with better explaination.

Hi Virii,

Let's see:
1)Additional stresses on the crank.
2)Additional stresses on the cam chain with all those missing pulses and then commensurate catch ups.
3)Instead of four cylinders running as designed you'd get two cylinders pulling for all get out with less than optimum mixture. Read: Soaking up fuel. While the other two loaf along sucking up energy.

If I'm not mistaken Cadillac tried something like this in the eighties and ended up with a bunch of cars that ended up with GMC engines.

If you want to save fuel and still have fun, I can only say " You can't there from here."

KZCSI

Yeah, the additional crank stresses came to mind. So you'd also be talking about refitting with parts from stronger alloys. The cam stress didn't immediately come to mind. Making the assumption that two cylinders fire concurrently, I figured you'd still be looking at the same amount of consecutive stress on the chain itself.


I'd never do it to my beautiful little Tess but there's a part of me that feels compelled to come up with ways that it could possibly work.


...besides, "Steampunk"ing a motorcycle seems a little too involved to be practical so this was the next thought...It'd look pretty good in copper, though, don't you think?

Post edited by: Virii, at: 2007/06/19 20:57

Hey Virii,
1 & 4 and 2 & 3 fire together, but they're each in different parts of their cycle. It's called a "lost spark" system.

The stress is not on the cams but on the cam chain, which needs no more strain, I can assure you.

KZCSI

Hmmm... buy a twin?