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Re: Twin dio possible?

Posted: Fri Apr 29, 2011 12:14 am
by Bear45-70
Majourlittle wrote:
xxjareebxx wrote:
Majourlittle wrote:Exactly, so I wonder why they did that? Was it to reduce torque on the coupler?
have them on the same stroke would make more torque on the coupler
Having them on the same stroke reduces the torque to nearly nil. Think of the cranks as two wheels on a live axel with posi. If both wheels are freespining with the same force, the posi doesent slip because there are no un-equal forces applied. If one wheel spins while the other doesent, the posi slips. If they alternate, you create a loading and unloading on that joint that creates an alternating torque on the joint. Thats the type of action you would get from opposing strokes.
You are wrong, it doubles the torque of a single cylinder set up. There is no way to make the torque zero unless the motor is stopped. You are thinking about this backwards with your posi example.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 12:28 am
by Majourlittle
double the torque at the end of the shaft, but if they are in sync, the midshaft is seeing an equivlent zero.

couple two electric motor shafs together with some tape. wire them up so that one spins CW and the other CCW (aka, they are spinning together when the shafts are taped together)

turn them on and off simultaneously. Does the tape break?

Turn them on and off independently. Does the tape break?

The engine in question is set up like the first example. Your reduced vibration example, the one that I wondered why they diddn't do like, is the second example.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 8:00 am
by burnt_toast
Bear45-70 wrote:
Majourlittle wrote:wonder why they chose to make the cycles the same? Were they afraid if they had the cycles apposing it would break their crankshaft coupler? That's a crazy build! Bet It would be some serious fun.
Making them same only increases vibration. Making the pistons 180┬░ out would make for a smoother running motor and even out the power. Instead of one power stroke every 360┬░ as it is now, you would have a power stroke every 180┬░ making a smoother running motor. This way is harder on the drive train too.
I agree. I think the only reason they did this is sheer simplicity. this way standard ignition will work. and seems like its in a drag scooter frame, so they didnt design this for street cruising or anything.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 8:02 am
by burnt_toast
Majourlittle wrote:
Trafficjamz wrote: I think they are on the same stroke, to simplify the timing. There is only one flywheel.
Boom! Jackpot!

So who's going to try it first?
someone make me some donations and I will SERIOUSLY consider doing this. I work at a fully capable machine shop.

maybe we could do collaborative build? I can build, who's down?

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 2:52 pm
by xxjareebxx
burnt_toast wrote:
Majourlittle wrote:
Trafficjamz wrote: I think they are on the same stroke, to simplify the timing. There is only one flywheel.
Boom! Jackpot!

So who's going to try it first?
someone make me some donations and I will SERIOUSLY consider doing this. I work at a fully capable machine shop.

maybe we could do collaborative build? I can build, who's down?
if i had a job i would help

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 3:20 pm
by Majourlittle
burnt_toast wrote:

someone make me some donations and I will SERIOUSLY consider doing this. I work at a fully capable machine shop.

maybe we could do collaborative build? I can build, who's down?
If you still had that white drag bike, I would throw some money into the pit. That would be the perfect home for a twin.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 3:27 pm
by SpreeMadness520
DO IT! :)

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 5:28 pm
by dv/dt
You cant just duplicate this, you need to go a step further! Triple Af16s! :surprise:

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 6:07 pm
by xxjareebxx
dv/dt wrote:You cant just duplicate this, you need to go a step further! Triple Af16s! :surprise:
That would he beast I bet it would sound like a zrt

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 9:33 pm
by burnt_toast
Majourlittle wrote:
burnt_toast wrote:

someone make me some donations and I will SERIOUSLY consider doing this. I work at a fully capable machine shop.

maybe we could do collaborative build? I can build, who's down?
If you still had that white drag bike, I would throw some money into the pit. That would be the perfect home for a twin.
blahh nahhh no way, that frame was under-designed imo, which is why I sold it. it really needed a longer motor stretch or wheelie bar to be in any way rideable.

with just 1cyl full corsa setup, you couldn't keep front down until 30mph and couldnt give more than 1/8th throttle taking off, it was just nuts..

new prjs in the works :urban:

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 9:37 pm
by Bear45-70
xxjareebxx wrote:
dv/dt wrote:You cant just duplicate this, you need to go a step further! Triple Af16s! :surprise:
That would he beast I bet it would sound like a zrt
The 3 cylinder configuration would create major unbalance and vibration issues and the ignition would be next to impossible to set up.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 9:38 pm
by burnt_toast
Bear45-70 wrote:
xxjareebxx wrote:
dv/dt wrote:You cant just duplicate this, you need to go a step further! Triple Af16s! :surprise:
That would he beast I bet it would sound like a zrt
The 3 cylinder configuration would create major unbalance and vibration issues and the ignition would be next to impossible to set up.
but it would sound awesome! :rock:

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 10:21 pm
by Spreetard
Trafficjamz wrote:
I think they are on the same stroke, to simplify the timing. There is only one flywheel.
I'm a little late chiming in, but also the engines being on the same stroke means the bottom end pressurizes at the same time, removing the need to isolate the cases with pressure seals on either side of the crank coupler. Easier to engineer on several levels.

Re: Twin dio possible?

Posted: Fri Apr 29, 2011 11:13 pm
by xxjareebxx
yes it would sound beast the zrt is the best sounding sled out there

Re: Twin dio possible?

Posted: Sat Apr 30, 2011 1:20 am
by eliteguy50
xxjareebxx wrote:yes it would sound beast the zrt is the best sounding sled out there
To each their own on the proper exhaust note but a lot of that has to do with the exhaust system. Ever heard a Vmax 4? If you are on a ZRT, I know you haven't seen one. :wink: