Has anybody ever thought of doing a smaller superbike engined locost ie. CBR600, GSXR600, ZX6R or R6. For low insurance and high performance wouldn't this be perfect? The only thing it is lacking in though is torque, but the engine will only weigh about 2/3 of a big superbike engine.

Adam

plus the engines are ten a penny. i thought of this put concluded they didnt have enough power. well, not enough to be loony anyway!

As cheap as those engines are, how about two of them mated to a central driveshaft?

I think I remember seeing a photo of a UK based hillclimb special that did that in a mid-engine configuration. Looked very neat. 8 cylinders, 2 gearboxes, 13,000 rpms.... hmmm.... might have to try that...



Edit>< Did a quick search and came up with Steve Owen's twin ZX9C hill climb car




[Edited on 3/2/04 by sgraber]

the problem with the lower powered bike engines is the clutch strength, fireblades and zx9's etc can have problems due to the weight they are pulling around,let alone a even lower powered engine with a smaller clutch, i personally think this would be a bad choice.

http://dsr.racer.net/images/chassis/oms/v8_hillclimb/left_front.jpg

http://dsr.racer.net/chassis/oms/gallery4.htm

thats one pretty car...

quote:

---

It utilizes two Kawasaki ZX9C engines placed back to back.
The engines drive a common jack shaft and then a prop shaft to the rear differential.
The gear selector on one engine was modified so that a common lever could be used for both engines.

---

How do you think power from the right engine was transferred to the jackshaft? Two engines facing away from each other like that will have their output shafts rotating in opposite directions. And one facing the front of the car, the other the rear. One of the rotations would have to be reversed, right? Using either an intermediary gearing setup, or... what?

How did he do it then?

Graber

[Edited on 3/2/04 by sgraber]

Jack shaft (Mach.), the first intermediate shaft, which receives power, through belts or
gearing, from a prime mover, and transmits it, by the same
means, to other intermediate shafts or to a line shaft.

Doesn't the cbr600 use the same clutch as the fireblade?. Enough people race them for a heavy duty replacement to be available. I would think the engine would struggle with the weight of a standard locost due to a lack of torque though.

yours, Pete.

like this i guess...


Image deleted by owner

with both ends of the shaft between the engine supported. any idea of what bearings could be used to hold the middle shaft in place, and what cogs to use to reverse the rotation of one engine?

That's pretty much what I sketched up. I was thinking that (2) 1:1 dog gears from a transmission in a custom gearcase would do the trick. The output shaft of the bike engine mated to a shaft that drives gear #1. Gear #1 meshed with gear #2 that has it's output tied to the end of the jackshaft. I would bet that the entire project could be bodged together from a discarded transmission.

Not a complicated project really if you had a lathe and a mill.

Note to self: Buy a lathe and a mill...

I notice that on Ebay(USA) virtually new R6 engines are selling for $400 (complete car kit)...

Or how about two 600s turned into a v8 as per this cyclone engine ?
http://www.cyclonepowerltd.co.uk/products.htm
Oldgit

If you mate two together you loose all the cost savings and more, it would be cheaper (and lighter) to build a 'busa engine'd car than a twin 600cc car, and a lot more reliable.
As for a single engine, I agree with elitewiring, and even if the clutch is the same as a 'blade clutch, its going to be slipped much more to get the car moving due to the lack of engine torque, so will take more abuse. Also the gears and crank etc will all be smaller / weaker and you may also find that they are geared lower than a bigger engine so finding the correct diff might be troublesome.
All in all I'd say that for the extra couple of hundred quid you'd pay for a blade / ZX9 / R1, its a false economy and really not worth the hassle of fitting a 600cc engine. From an insurance angle I cant imagine there would be a great deal of difference anyway, mines only just over £200 fully comp now, and if you are under 25 you are always going to get hammered regardless.

Chris

Thanks, interesting.

Adam

well in the USA I was looking at diff's out of a tbird which I can get a 4.56 gear for....if you were building a 600cc locost I would think it would be for pure handling and short runs only. I have thought about it for a around town and autocross toy...

nick

You certainly won't want to put a 4.56 with a bike engine, you'd top out around 85mph I should think, and b forever changing gear. I would also think the Tbird diff weighs a ton.

I use a 3.54 and still get only around 110mph.

well the v6 tbird diff has a alloy case and is ony a 7.5" gear (good aftermarket here) and it can be easily modded for seirra axles. so the weight is not too bad on it. well I am not looking for a top end car but one to take the twisties.and I can always have a spare diff to swap in for more top end. thing I am getting at is would a 4.56 gear allow a 600cc car to be built?

Can you determine the shift points based on your ratio's. Will you be reaching 12K rpm at 30MPH, grab another gear, hit 12K rpm at 45MPH, need another gear, etc... etc... ? The net effect could be that you spend simply waay too much time between gears, having to use all 6 of them just to keep up with traffic?
<devil's advocate off>

I would never say don't try it though! :-)

Remember - Weight is the enemy, especially at this end of the torque spectrum.

[Edited on 3/18/04 by sgraber]