1000cc two stroke

[FilthyLuka]

You wanna go V-twin dont ya? One under the bike and one under the seat takes care of where the pipes go, a bottom end is another story, I think the easiest way would be to have an RGV, or NSR bottom half beefed up. Graft a fat arse dry clutch on the side, get extra strength aronund the casings by just adding more Aluminium, and presto. Also takes care of nearly every other problem you can think of. Even what bike to mount it in.

Not quite the same feat of engineering, but I'm a simple guy.

Thats a fucken marvellous idea. Will measure up a RGV 250 crank case a buddy of mine has in his garage, see if its do-able.

Although i was talking bout that rotax boat motor. Cause the exhaust ports are above the intake ports, so the pipes would just go straight out under the seat.

The RGV plan sounds good, however, even if you slap on a great big fuck off dry clutch (off a 916 maybe?), will the transmission be able to hold up with excess off 160 horses? We would need to beef up the transmission aswell. Im not really that experienced with gearboxes, does anyone know what this would entail?

[Drew]

will the transmission be able to hold up with excess off 160 horses? We would need to beef up the transmission aswell. Im not really that experienced with gearboxes, does anyone know what this would entail?

That's why I said about re-enforcing the gearbox housing. The most likely problem of increasing the power that much, is that it will literally force the gear shafts apart, bigger bearings can be fitted with simple machining, and if ya put a plate around the outside of the casing on the line of bearings, it'll hold up just fine.

I too was thinking Ducati clutch, but not really up to it I dont think. Aftermarket dry clutch for a GIXXER thou or similar would do the trick.

[F5 Dave]

OMG ok sorry guys but this is where I sign off. RGV bottom end can hardly handle it's own meagre output even if it was possible to modify a 125 to cope with a 500cc (which it clearly will be wayy too small) 2 of the 3 weak points on the RGV are crank & gearbox.

Make mine a handle of Becks & I'll see y'all back at the carrel.

[Ixion]

RGV bootm end wouldn't work. No way the crank would take it , or the main bearings, and like the man said, crankcase just can't pump enough air. Remember, on a two stroke the crankcae is a pump. Pumps gotta be big enough.

Buell/harley gearbox should be heavy enough, it''s torque that matters most to a gearbox, and two strokes don't deleop so much of that. Gearbox bearings will be going faster than they were designed for, so the lubrication may be an issue.

[tpft]

I didn,t read all the posts so unsure if anbody else mentioned it, but yanks have been making 1000cc twins for years, using 2 cr 500 topends, on a custom b/end, i,ve got a link somewhere............

on rgv,s we built a big block one using 2 rg 150 barrels (they nearly bolt on)
and boring them two take kdx 200 pistons.

[Richard Mc F]

Buell/harley gearbox should be heavy enough, it''s torque that matters most to a gearbox, and two strokes don't deleop so much of that.

Sorry to be the wet blanket Les, 2 smokin' thangs deliver more torque.....thems not rev loike an otto cycle fourstoker can, I was of the inclination to believe that 'orsepower ( not them new fangled kilofloozies) were 'ssentially a product of torque versus rpm.....less rpm needs more torque to deliver said 'orse.

Any soul lucky enough to bear witness to the coming of the power band has experienced torque

[Ixion]

Not per stroke though. Which is what matters to the gearbox. Why big singles are so hard on gearboxes. Bang, bang, bang every power stroke a hammer blow on the poor old gears (and chain) Two smoker has less bang per stroke, but (more than) makes up for it by having twice as many strokes.

You're right of course about horse power being the product or torque and rpm. But the two stroke should be revving considerably higher than the doner Harley. So , higher revs , same horsepower, lower torque , and less 'bangy'. Or, maybe , more horsepower , but still proportionately less than the extra revs. Which may (as I noted) be an issue for the bearings.

[Richard Mc F]

Not per stroke though. Which is what matters to the gearbox. Why big singles are so hard on gearboxes.

Ageed but the point was to be made,we should not to confuse torque with impact or loadings ..........such technical abstracts need to be face to face with beer at hand and tongue in cheek

[FilthyLuka]

So the hacked RGV idea is outta question.

So we're either gonna have to patronize Mr Rotax for an engine (which will be parralel twin) or cut a custom crank for a vee....

Sounds fun

[aff-man]

Custom crank for a v on inline twin would be the way to go....

I've seen a very interesting v8 made from 2 bike engines with a custom crank...

Would also mean you can be more choosy with a gearbox.

As for a clutch think about a barnett (or whatever they are called) racing clutch off ebay or a stock one http://cgi.ebay.com/ebaymotors/04-05...spagenameZWDVW. Relatively cheap and built for drag bikes so will be more than capable of handeling the horsies not to meantion the interesting power curve said bike would produce.

few other ideas floating around in the old noggin

[pete376403]

The Maico single cylinder 2 stroke range was developed from a 125 - they just kept adding more bore and stroke, finally ending up with a 501 . But the cases remained relatively unchanged. Two of these would give you your 1000 twin. Or a couple of Yamaha SC500s if you could find them
If you were building a v twin, you could do it with two single cyl engine cases welded together, side by side rotated arounf the line of the crank. As the cranks are pressed together it would be relatively straighforward to built a twin cyl crank from single cylinder bits.

[F5 Dave]

I didn,t read all the posts so unsure if anbody else mentioned it, but yanks have been making 1000cc twins for years, using 2 cr 500 topends, on a custom b/end, i,ve got a link somewhere............

on rgv,s we built a big block one using 2 rg 150 barrels (they nearly bolt on)
and boring them two take kdx 200 pistons.

TePuke huh? That's close enough to Farm Steadman to make me suspicious.

imdyings prediction of cost is pretty close to the mark if one was trying to engineer this and buy all the component parts to make a bike. I'm most of the way through a Big bore 2 stroke using commercially available aftermarket parts. It's taken months & about an R6s worth of money.

This is considerably more ambitious. Even buying the Rotax & adapting a gearbox etc would be way beyond the majority of people's experience. Making crankcases & custom cranks, well,

So how much was in the budget? or shall we be honest & say this is going nowhere.

[FilthyLuka]

So how much was in the budget? or shall we be honest & say this is going nowhere.

Its a theoretical situation, why throw money at a project before the plans have been made?

I wan't to figure out what the best way to make a 1000cc two stroke Vtwin is, figure out what frame would be best suited for the application, work out the rough cost and go from there.

[onearmedbandit]

Then we just need some sucker to test ride it

Someone call me?

[F5 Dave]

Well Brittens first QF forks fell to bits

so what chance a bunch of enthusiastic novices in a shed of producing something (Barring in mind JB had the money to back up research & development) that would hold together? I feel a Youtube moment coming on.

. . . Actually I have no question that there would ever be a production of a wheel turning so OAB is perfectly safe afterall.