Two engines, one bike

Augidog, thanks for the input. I understand your point and it makes sense but when you are pedaling are you not then being another "engine"? Are you assisting the engine or is it vice-versa? Does either of you negate the other or do both of you speed up or ease the pressure on the other? This is a very interesting and important subject to me and I have absolutely no experience with it. I am trying to digest all of this info and it will help me make a decision. A friend has told me he thinks the two centrifigul clutches should make it unnecessary to sync the engines. Thanks again.
 
well, i wish i had the funds to experiment, and i don't envy you your research.

while i believe the 2 centrifugal clutches would allow both engines to operate at the same time, i'm not buying that they'd synchronise themselves, power-wise...i think all that would happen is the slower/weaker one would only be making noise while the faster/stronger had the load. and, if i'm correct, once you've the attained engagement-rpm of the weaker one, then it becomes a drag on the stronger one.

again, i think anything could be synched with anything, including the human engine. but humans are able to instinctively adjust, or synchronise, which is one of my favorite parts of this motorsport. i assist the engine, or the engine assists me, and it's my choice.

so, you're saying you're willing to do the science (play with 2 throttles) every time you want dual, or triple, drive...again only opinion, but it sounds like pre-engineered trouble to me. and you haven't even begun to figure out how to make sure that your mismatched system will synch-up as pertains to gearing to tire-on-road, powerband/range, temperature, etc... heck, adjusting myself to the throttle-response of 2 different engines is enough to convince me i wouldn't bother if i had the choice ahead of time. like dog-sledding with a husky & a shepard, both good dogs but with entirely different sled-pullin attributes. now that i read that last line: even synchronizing the 2 dogs would be an easier task...they can learn to work together, while the engines never can.

EDIT: what the heck am i doing up so late? everyone, it's been a GREAT weekend here on the board, thanks to you all.

kenspice...to be continued :)
 
a new morning-thought, about engagement rpm: even when under one engine, it seems you have that extra drag of the dormant drive to work out yet.
 
Augi, glad you stayed up as your input is well taken. Point in case, I do not intend for either engine to be chasing the other as this would only happen if I were looking for speed. Using only one engine (the other is idling and this only in hilly country). As the main engine slows and begins to labor, I ease the throttle up on # 2. I think I would be able to feel and hear the main engine picking up more of the load until I could again return the # 2 to idle. I agree that at high RPM,s the weaker of the two would become a hinderance. During off seasons and flat roads, remove 3 nuts and the clip-on throttle and I'm back to one bike and one throttle. The whole object is to get my old body over the hills with a bigger load and only at low RPM,s. As far as temperatures go, putting less load on # 1 would lower the temp., Don'cha think? As far as exercise... I will have the strongest thumbs around. The other option, of course, is to take the 35 off during hunting and install the Tanaka and lose all of the advantages that I am dreaming up.
 
temp was referring to engine specs, 2 different engines would be affected in different ways by everything.

throttling: one throttle would be fine if the drives were identical.

man, please don't look at my input as discouragement...i'm being devil's advocate and engineering assistant rolled into one...please do go on :)
 
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On your morning thought- With the clutch of # 2 disengaged, the drag of it's belt should be almost negligable
 
Never one throttle. If I have to sync the engines I will quit this project. One main engine- the other is to assist on hills only.
 
man, please don't look at my input as discouragement...i'm being devil's advocate and engineering assistant rolled into one...please do go on
you don't have to do anything except what you want to do :)

i'm pretty sure you're thinking about this detail, and i should leave you alone now, but i look forward to watching this progress :cool:
 
Really Augidog, I appreciate your input and want more of it and others as well. I was only referencing the "one throttle" aspect. I think it would be much too difficult to sync 2 engines with one throttle to gain top speed. I just meant to emphasize that I am only interested in low rpm's on hills or heavy load conditions and to use the engine#2 only when absolutely necessary or as a spare. I also intend to get two GEBE built wheels if I deceide to go on with this. I love these Wa. mountains and want to see as much of them as I can.
 
By the way, Jemma, "Twinnie" is a good name. Thanx. Or "Double Barrel", Etc. Etc. My wife (Japanese) calls it "Mondai" - Trouble.

lol ... I was thinking more along the lines of Kamikazi or 'divine wind' (the original by the way, not that of later connotations)... but mondai is good - reminds me of monday mornings..

I think two engines of the same type would be better because they would have the same torque and power characteristics - and also if they have the same drivetrains there is less chance of problems (and no duplication of spares).

As to your thought of syncronisation to get top speed I think there would be a way to sync the ignition systems by linking the low tension circuits of both engines although the mechanical details elude me (I have about as much physical ability with electricity as I have in playing rugby...)

However, I dont think you will need to - because if you are roadrunning that will take care of itself quite simply. The problem with my little GEBE on Anita was that she would pull to a certain point and then the engine ran out of puff well below (at least I think so) the top RPMs of the engine. I am good with the sound of motors (telling which cyclinder wasnt firing on a straight 6 by guesswork at the first attempt... I got alot of looks from my ex's grandad who used to be a mechanic.. if he could see me now lol). The problem was that with the one engine the torque curve ran out before the engine hit top revs becase of the weight.... with two engines they can work off each other and will therefore be able to (sans LPA) get higher in their rev bands and therefore higher top speed...

Thinking of Roadrunners ... wasnt there a plymouth under that name a few years back (aka before I was born...). I've seen the 402 M/Cleveland engine - that things bigger than whole cars here...!

hmmm Mondai RoadRunner sounds pretty good to me:D

But I guess your wife would happily kill me if I even mentioned dropping a 440 6-pack into a schwinn lol...

Jemma xx
 
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