1000cc two stroke

[FilthyLuka]

Well, ixion had an idea in a 250cc thread, and a bloody brilliant idea it was

Take two 500cc two smoker top ends, common crank case and end up with a 1000cc two stroke. :eek5:

Here in lays the problem, unlike a fourstroke where there is just oil sloshing about, a two stroker crank case needs all them funky fuel passage ways and stuffs.

Good thing i have access to a couple bung crank cases i can have a wee squiz at to see how to do it :yes:

Anyway, so currently the input thats requried is:

1) Which top end? KX or CR?
2) Crank shaft? How we gonna do that homes? Hack up the old one off a donor kx/cr and lengthen it to accept to con-rods?
3) Crank case, whats the best option? CNC? Cast?
4) Frame, what can we throw the bastard in that it wont chew threw?
5) Go fast bits, big bore? 1200cc vtwin perhaps?

Purely Theoretical, might go somewhere one day.

What you guys think?

(hmm, where did i put that modelling software....)

[Ixion]

Crankshaft, it needs centre bearings and seals or a labyrinth. So the easiest way would be to use two donor cranks. Select ones which have pressed in mainshafts, and machine a new centre main shaft.

Was there ever a 500cc single with side mounted rotary valves? That would make the induction easier. Otherwise, just follow the RGV/TZR model.

A bigger problem will be a transmission. The donor gearbox and clutch are unlikely to cope with doubling the power.

[FilthyLuka]

A bigger problem will be a transmission. The donor gearbox and clutch are unlikely to cope with doubling the power.

Seeing as the crank case is being custom fabricated anyway, is there any reason we can make it to take a GSXR-750 or GSXR-1000 gearbox? Going with GSXR randomly, would there be a better option?

Clutch could also come from a similar bike, perhaps with a lock up system so it doesn't slip when it hits the power band

[Ixion]

That would make the crankcase a very complex fabrication.

I reckon the Neptunic gentleman is on to it. use a non unit gearbox/clutch from a Harley or Buell.

That should handle the power (maybe) and makes the crankcase easy.

[crazybigal]

there was a story on a guy in kiwibiker mag a few years ago.
He used 3? rm250 motors from memory.
I remember he had to cast his own crankcase as the rm ones would not be upto the job. he had a way thicker casing.
Vibration was one of the main problems.
if you want to read it ill scan it and pm it to you if you like.


Well, ixion had an idea in a 250cc thread, and a bloody brilliant idea it was

Take two 500cc two smoker top ends, common crank case and end up with a 1000cc two stroke. :eek5:

Here in lays the problem, unlike a fourstroke where there is just oil sloshing about, a two stroker crank case needs all them funky fuel passage ways and stuffs.

Good thing i have access to a couple bung crank cases i can have a wee squiz at to see how to do it :yes:

Anyway, so currently the input thats requried is:

1) Which top end? KX or CR?
2) Crank shaft? How we gonna do that homes? Hack up the old one off a donor kx/cr and lengthen it to accept to con-rods?
3) Crank case, whats the best option? CNC? Cast?
4) Frame, what can we throw the bastard in that it wont chew threw?
5) Go fast bits, big bore? 1200cc vtwin perhaps?

Purely Theoretical, might go somewhere one day.

What you guys think?

(hmm, where did i put that modelling software....)

[xwhatsit]

You might want to talk to the fellas at University of Auckland's Formula SAE team. They manufactured their own 500cc V-twin from two Yamaha thumpers. Built crankcase, crank, all of that stuff. There's a video somewhere.

Of course that's a 4t, which is much simpler in that respect as you say (top end is where all the interesting stuff is).

[Pwalo]

Just stick two TS400s together. Now that would be a challenge to kick over.

[Ixion]

Pssahhw. That's only 800cc. Good point though, it'll be a beast to start.

[Blackbird]

The Yamaha Vmax4 snowmobile engine is a 4 cylinder 2 stroke 750cc. Wonder whether that would fit nicely in a bike frame with 4 expansion chambers? The modern Tul-aris race bike is based on a snowmobile engine.

Then you have the range of big outboard 2 stroke engines. The Crescent 3 cylinder was campaigned successfully on European race tracks in the 70's although that was only 500cc.

Nothing quite like the sound of a multi-cylinder 2 stroke, having been priveleged to see the works Yamahas of Read and Ivy on a number of occasions - horny or what???:sweatdrop

[FilthyLuka]

Nothing quite like the sound of a multi-cylinder 2 stroke, having been priveleged to see the works Yamahas of Read and Ivy on a number of occasions - horny or what???:sweatdrop

hmm, i wonder what it would sound like if we made it fire like a harley....

[Pwalo]

Not to mention the smell of burnt two stroke. Hmmmmmmm.

[FilthyLuka]

Not to mention the smell of burnt two stroke. Hmmmmmmm.

thats actually a very good point

How much oil would this thing eat through?

[crazybigal]

speaking of boat motors, remember the konig
Kim Newcombe as the New Zealander who came second in the 1973 World 500 Grand Prix Championship.
He’s also famous for the bike he rode, which he developed himself, using the engine from an outboard motor, then refined for the German manufacturer Dieter Konig who became his friend and mentor

The Konig engine itself presents quite a few engineering challenges. In a solo motorcycle, the engine is mounted with the cylinders fore and aft. Because the unit was originally designed to have copious quantities of cold sea-water to cool it, changes needed to be made when it was mounted in a motorcycle. A large capacity copper radiator is one component, but the motor also has a specially-cast magnesium water sump which bolts beneath the crankcases. This means that the exhaust pipes, which on the outboard come out the bottom of the cylinders, must exit from the top, and this presents problems in clearing the carburettor. Most of the racing motorcycle engines used down-draft Solex or Weber carburettors, but Newcombe’s employed a pair of 42mm Tillotsen pumpers. As well as being more efficient, the American carbs allowed much more room for the expansion chambers, which are Siamesed from four exhaust ports into two pipes. A large diameter rotary valve sits atop the crankcases, driven by a toothed belt. Gearbox is an AMC, fitted with a five-speed cluster. The clutch, which is a lathe-type, is driven from the engine sprocket by a Hi-Vo chain. Rod cast and machined the Ceriani-pattern brakes himself, and Ceriani forks are used at the front. The voluptuously -sculptured fuel tank is another piece of Tingate craftsmanship.




The Yamaha Vmax4 snowmobile engine is a 4 cylinder 2 stroke 750cc. Wonder whether that would fit nicely in a bike frame with 4 expansion chambers? The modern Tul-aris race bike is based on a snowmobile engine.

Then you have the range of big outboard 2 stroke engines. The Crescent 3 cylinder was campaigned successfully on European race tracks in the 70's although that was only 500cc.

Nothing quite like the sound of a multi-cylinder 2 stroke, having been priveleged to see the works Yamahas of Read and Ivy on a number of occasions - horny or what???:sweatdrop

[crazybigal]

id love to see how long that monster stays in 1 bit!

I promissed myself I wouldn't post here... but: http://www.trickracing1.com/The%20First%20CR500%20Made%20into%201000cc.html

[Ixion]

Well, there y'go. Now we know it's possible.

[onearmedbandit]

Oh fuck, I think I may just have been converted...

[Ivan]

Ohhhhhhhhhhhhhhhhh

That is hot....

I love the sound of 210 horses how hard to ride tho????

[Ixion]

Fuck me. That EFI turbo charged intercooled Banshee should go straight into a RZ350 frame (same engine basically).

I've *got* an RZ350 frame.

I'm going to have to go and have a lie down.

[FilthyLuka]

Fuck me. That EFI turbo charged intercooled Banshee should go straight into a RZ350 frame (same engine basically).

I've *got* an RZ350 frame.

I'm going to have to go and have a lie down.

gimmie....

[gijoe1313]

And madness takes its toll ... :wacko: Cor blimey guv'nor wouldn't that be a monster build! :sweatdrop

What a feat of mechanical engineering and perzackerness, but having the cojones to really give it a twist of the wrist ... priceless!

[MaxB]

How about a TZ750 motor from the 70s? Or use the concept: a 4-cylinder, 2-stroke race motor. Woosh!

Modern materials, decent clutch, big-bore and efi should be a good start.

[Ocean1]

I promissed myself I wouldn't post here... but: http://www.trickracing1.com/The%20First%20CR500%20Made%20into%201000cc.html

What's the block? They didn't make it, it's no short-run item.
Be a monster, but it's not a unique arangement. I'd be real interested in how a V would behave but we already know what big 2T parallel twins do.

On a 2T V2... you've already got a dual crank, what firing angles do you reckon?



Fuck me. That EFI turbo charged intercooled Banshee should go straight into a RZ350 frame (same engine basically).

I've *got* an RZ350 frame.

I'm going to have to go and have a lie down.

Doubt it'd fit without some serious cutting and tucking, all that extra plumbing is hardly tucked nicely away. OK on a drag bike but you'd have a hell of a job tidying it up for street use.

[Subike]

have a look at this one guys

dont think there would be many of you 2 strokers could hold the front wheel down
http://www.kawasakisa.co.za/news_details.php?news_id=87

[FilthyLuka]

have a look at this one guys

dont think there would be many of you 2 strokers could hold the front wheel down
http://www.kawasakisa.co.za/news_details.php?news_id=87

Yeah, people have been doing that with the kawasaki's for a while. 'Parrently the way the crank is designed means its relatively easy to hack and add on more cylinders.

One guy in the states had a 1500cc V6 h2

[Ocean1]

have a look at this one guys

dont think there would be many of you 2 strokers could hold the front wheel down
http://www.kawasakisa.co.za/news_details.php?news_id=87

Oh goodie, take possibly the most evel handling frame ever made, chop up a tripple in which the middle cylinder cooked at the slightest hint of prolonged revs and wedge another one in. Add a set of ancient slender rubber and stir :pinch:

One of the very few vehicles I believe I might decline to attempt to pilot.

[cold comfort]

Oh goodie, take possibly the most evel handling frame ever made, chop up a tripple in which the middle cylinder cooked at the slightest hint of prolonged revs and wedge another one in. Add a set of ancient slender rubber and stir :pinch:

One of the very few vehicles I believe I might decline to attempt to pilot.

As a past owner of 750 H2 I totally endorse that comment. I'm sure divine intervention was all that kept me alive. The Z900 to follow was a pussy in comparison!

[steveb64]

IIRC there was a Speedway midget (TQ?) back in the mid-eighties that was a V4 made from 4 YZ465 (may have been 490's) engines. I have the vague recollection that Graham Standring was the driver - or at least involved with the project... but it was a long time ago...

[breakaway]

dont think there would be many of you 2 strokers could hold the front wheel down

Now why would you want to do a silly thing like that? :spudwhat:

[skidMark]

Whats up with this donor crap, build it from scratch u lazy buggers.:bleh:

[skidMark]

As a past owner of 750 H2 I totally endorse that comment. I'm sure divine intervention was all that kept me alive. The Z900 to follow was a pussy in comparison!


Yeah mate, there have been some spiteful bikes built over the years. The old GSX-R 400 Impulse was known for randomly highsiding u off mid corner. Killed alot of people that model did.

[FilthyLuka]

Yeah mate, there have been some spiteful bikes built over the years. The old GSX-R 400 Impulse was known for randomly highsiding u off mid corner. Killed alot of people that model did.

Mate, i've taken a H2A kawasaki for a spin, not pleasant. Trust me on this one, impulse is great compared to that stroker...

So Pretty much, so far we have:

Vtwin 1000, two 500 top ends, firing order to be decided
Buell Gearbox design, so drive from the crank to the clutch via chain/belt or whatever can take 200+ horses
Frame = yet to be decided

Im gonna go drop an email to those UNI boys, see what they think of the idea :laugh:

[onearmedbandit]

Yeah mate, there have been some spiteful bikes built over the years. The old GSX-R 400 Impulse was known for randomly highsiding u off mid corner. Killed alot of people that model did.

What???? Rode one for a couple of years, very hard too, never tried to highside me. Never heard of a 50hp 4 stroke being a killer motorcycle.

[NSR-Dan]

Why dont you use one of those 1300cc 3cyl 2 stroke engines out of a jet ski.

[F5 Dave]

Well I promised not to post on such an "idea while at the pub" thread, but I guess I'm not infallible either.

Just buy one from friendly Rotax dealer
Engine Type 995 SDI

* 2-stroke
* 2-cylinder
* 997.5 cc
* 120 kW / 163 HP
* liquid cooled
* semi-direct injection
* E-RAVE (electronic ROTAX Adjustable Variable Exhaust)


Oh yeah. Impulse? dangerous?:lol::lol: Yeah like a GN250.

Gotta watch those Toyota Corollas eh? They'll spin up & click into reverse & do 100mph backwards without warning.
:wacko:

4 legged Pub barstools re known for being dangerous, tip forward on one & it will send you into orbit & you'll knock your head on bits of Skylab that I hear are still up there.

[bungbung]

old GSX-R 400 Impulse was known for randomly highsiding u off mid corner. Killed alot of people that model did.

My impulse was pretty random at starting.
Jeez you talk shit Mark

[FilthyLuka]

Well I promised not to post on such an "idea while at the pub" thread, but I guess I'm not infallible either.

Just buy one from friendly Rotax dealer
Engine Type 995 SDI

* 2-stroke
* 2-cylinder
* 997.5 cc
* 120 kW / 163 HP
* liquid cooled
* semi-direct injection
* E-RAVE (electronic ROTAX Adjustable Variable Exhaust)


Oh yeah. Impulse? dangerous?:lol::lol: Yeah like a GN250.

Gotta watch those Toyota Corollas eh? They'll spin up & click into reverse & do 100mph backwards without warning.
:wacko:

4 legged Pub barstools re known for being dangerous, tip forward on one & it will send you into orbit & you'll knock your head on bits of Skylab that I hear are still up there.

Hmm, again, good idea, but no V-twin. Still haven't hear back from them uni boys, probably to busy CNCing to check emails... bleh

Who is our friendly rotax dealer around these parts? Cause i think i may have a frame in mind for one o' dem fools.

Rip cord is all sorts of re-assuring aint it? We would need to add on a sprocket or gear onto the crank, then run a short chain from that to the clutch/gearbox.

Sounds good :) Who stocks rotax? And how many of my internal organs will i need to sell?


My impulse was pretty random at starting.
Jeez you talk shit Mark

Lets not allow this thread to degenerate into another "Mark, your a prat" Thread... Theres a thread about a 250 ninja somewhere that has that covered

[Str8 Jacket]

Mate, i've taken a H2A kawasaki for a spin, not pleasant.

Really? I loove those bikes! There was one at Wanganui, fucken flying he was and it sounded mint!!!

If I ever won lotto I would buy a 2smoker of every size for my garage! :first:

[F5 Dave]

My impulse was pretty random at starting.
Jeez you talk shit Mark
Does he talk it? It just seems to spew out. I mean I briefly & without particular interest saw the I'm sulking & going if everybody is going to be mean to me, but learn not to let your over active imagination get confused with reality. People will just end up thinking that you're a tit.

[F5 Dave]

Really? I loove those bikes! There was one at Wanganui, fucken flying he was and it sounded mint!!!

If I ever won lotto I would buy a 2smoker of every size for my garage! :first:

Yeah he just popped through the door not more than 10 min ago. Bit of a demon on a CT postie bike.

[Str8 Jacket]

Yeah he just popped through the door not more than 10 min ago. Bit of a demon on a CT postie bike.

Does he ride it on the road at all? Was up at the summit one day when one came flying past....

[FilthyLuka]

Hmm, it appears rotax make more than one particular 1000cc two smoker twin

This one in particular, not the thingie on the side, grind it off and replace with a drive gear to go to the transmission?

135 Brake Horse Power on this model.

[FilthyLuka]

Really? I loove those bikes! There was one at Wanganui, fucken flying he was and it sounded mint!!!

If I ever won lotto I would buy a 2smoker of every size for my garage! :first:

It wasn't pleasant.... but good god it was sexy... If i had a collection of bikes, it would totally be in it :)

[F5 Dave]

Does he ride it on the road at all? Was up at the summit one day when one came flying past....
Um, the postie bike? yeah, used to be every day:scooter::innocent:
. . . but I think you mean the 750 so I doubt it, but on the other hand it wouldn't surprise me come testing time.

[FilthyLuka]

Hmm, it appears rotax make more than one particular 1000cc two smoker twin

This one in particular, not the thingie on the side, grind it off and replace with a drive gear to go to the transmission?

135 Brake Horse Power on this model.

Going on from this, as you can see in the pic that was in the quoted post, the exhaust ports exit above the intake ports. This would mean that

A)Underseat exhaust is a go
B) Room for expansion chambers :crazy:

Im assuming that, because we are talking about two 500cc cylinders, we would need two big arse fuck expansion chambers. So pretty much all the room under the subframe will be taken up by expansion chamber... What issues do you fulla's think this would lead to? other than a toasty bottom

[Drew]

Im assuming that, because we are talking about two 500cc cylinders, we would need two big arse fuck expansion chambers. So pretty much all the room under the subframe will be taken up by expansion chamber... What issues do you fulla's think this would lead to? other than a toasty bottom

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.

[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:niceone:

[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:love:

[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-GSXR-750-GSXR750-COMPLETE-CLUTCH-BASKET-PLATES_W0QQcmdZViewItemQQcategoryZ35595QQihZ017QQi temZ270208687495QQrdZ1QQsspagenameZWDVW. 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, :pinch:

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 :whistle:

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?:sweatdrop 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.

[FilthyLuka]

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?:sweatdrop I feel a Youtube moment coming on.

If the enthusiasts consist of fulla's like yourself, ixion, imdying and a few others that come to mind, i would guess the chances would be rather high.

Im currently stacking up docs and white papers that im finding on the internets and off folk like yourselves...

A project is doomed to failure if the planning isn't done

[T.I.E]

can ya make me a sv2000s? V4? put two sv engines together?
maybe two tl1000r engines would be better?

[FilthyLuka]

can ya make me a sv2000s? V4? put two sv engines together?
maybe two tl1000r engines would be better?

Would probably be alot simpler than this project...

[Ocean1]

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.

I thought one of the design criteria for 2T cases was minimum volume, to optimise downstroke compression ratios. If so you’d make the crank first, then the cases, with minimum comfortable clearance from the crank swept path.

Think a Buell box would be heavy enough, 150hp examples exist and if you’re worried about a bit extra you could just change the primary drive ratio up and compensate at the back sprocket. Can’t see revs being an issue, bearings are rated to more than standard revs. Clutch might need attention though, for both torque and rev reasons, but again I think it’d be worth trying the standard set-up with slightly heavier springs if nesc.

There’s already kits available to convert Buells to chain/sprocket final drive, not that the belt’s necessarily a weak point but you’re going to be messing with ratios and sprockets are cheap…


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.

Buell frame, mount the engine off modified heads to existing frame mounts, handles well and is rigid enough. Only thing I’d be worried about is the frame work hardening and cracking from vibration, so use modified standard Buell rubber mounts.

Only reason I like the idea of a V2T is because there’s a big difference between an IL2 4T and a V2 4T, the most attractive of which is good tractable power from the V. So I’d be fascinated to see how a V2T would behave.


How about a composite carbon/kevlar one?

/edit: Rough cost...10 metres of 195gm dual twill, about a thousand bucks, plus another $200 for resin... $300 for misc supplies. Probably make it for under $2000, assuming all went to plan (which it wouldn't). Then we just need some sucker to test ride it :whistle:

High risk design issues, very cool but it’s adding unnecessary work to the engine development. Save it for the #2 prototype. :niceone:

[FilthyLuka]

I
High risk design issues, very cool but it’s adding unnecessary work to the engine development. Save it for the #2 prototype. :niceone:

Err... i actually have a buddy of mine who can do that for me provided i draw up the plans and give him enough money/beer.

Im currently staring into an RGV 250 Crank Case, trying to work out a decent design for transfer ports, might just completely rip off the RGV250 Crank-Case Design, draw up a custom crank and change some of the dimensions to suit the CR500 top ends. Its the transfer ports are whats kinda worrying me, seeing as its a 500 cc cylinder, not a 125, obviously the transfer ports would need to be considerably bigger.

(and guys, making a custom engine has been a dream of mine for quite some time, and now im actually earning the funds to be able to go out and do it. The second the Gixxer is all sorted and the next lot of funds come through, there will be a CR500 donk in my garage. If all else fails, i will fit the stock cr500 to a NSR250 frame and have a track bike...)

[deanohit]

I remember seeing in Dirt Wheels a few years back a completed CR1000V engine made from 2 CR500 engines that was built in Europe, it was being put in a quad bike built for hill climbs like Pikes Peak.

[Ocean1]

Err... i actually have a buddy of mine who can do that for me provided i draw up the plans and give him enough money/beer.

Im currently staring into an RGV 250 Crank Case, trying to work out a decent design for transfer ports, might just completely rip off the RGV250 Crank-Case Design, draw up a custom crank and change some of the dimensions to suit the CR500 top ends. Its the transfer ports are whats kinda worrying me, seeing as its a 500 cc cylinder, not a 125, obviously the transfer ports would need to be considerably bigger.

(and guys, making a custom engine has been a dream of mine for quite some time, and now im actually earning the funds to be able to go out and do it. The second the Gixxer is all sorted and the next lot of funds come through, there will be a CR500 donk in my garage. If all else fails, i will fit the stock cr500 to a NSR250 frame and have a track bike...)

Edit: Carbon frame design is tricky, need to specify load cycles etc, could talk to High Modulus in Warkworth.

Don't think Mr Suzuki is going to be too worried about you lusting over his case porting arangements, but they're a component of the overall porting design, so if you're going to use CR500 top ends why wouldn't you copy Mr Hondas cases? ANd CR500 cranks for that matter, just need to figure out the centre bearing/seal.

[F5 Dave]

. . I posted the major reason not to bother though, here (http://nzsbf.co.nz/forum/viewtopic.php?f=1&t=1952). Bliss.

Well it'd be ok for poppin down to the shops. . . :shutup:

[deanohit]

Thought you engineering fellas might also be interested in this, the Desmo Harley (http://thekneeslider.com/archives/2007/07/12/desmoharley-italian-american-v-twin-completed/). Completely custom crankcase to make the Desmo gear work, pretty unique.

[Ocean1]

I remember seeing in Dirt Wheels a few years back a completed CR1000V engine made from 2 CR500 engines that was built in Europe, it was being put in a quad bike built for hill climbs like Pikes Peak.

Details man, dimensions, spec's...


Thought you engineering fellas might also be interested in this, the Desmo Harley (http://thekneeslider.com/archives/2007/07/12/desmoharley-italian-american-v-twin-completed/). Completely custom crankcase to make the Desmo gear work, pretty unique.

Wonderful entheusiasm. But why bother?

[FilthyLuka]

Edit: Carbon frame design is tricky, need to specify load cycles etc, could talk to High Modulus in Warkworth.

Don't think Mr Suzuki is going to be too worried about you lusting over his case porting arangements, but they're a component of the overall porting design, so if you're going to use CR500 top ends why wouldn't you copy Mr Hondas cases? ANd CR500 cranks for that matter, just need to figure out the centre bearing/seal.

That was the plan, its just i don't have a Honda two smoker V-twin crank case readily available :shutup:

Alot of this is going to be more clear once i actually see the internal workings of the CR500 so my brain can put a picture to the idea


Thought you engineering fellas might also be interested in this, the Desmo Harley (http://thekneeslider.com/archives/2007/07/12/desmoharley-italian-american-v-twin-completed/). Completely custom crankcase to make the Desmo gear work, pretty unique.

No sir i don't like it

[deanohit]

Details man, dimensions, spec's...

I know, I know, I'm busy furiously looking through my mags at the mo' looking for the article!

[Pixie]

Why a V-twin,other than fashion?
They make so much engineering sense - that's why Rotax don't make one.
The sensible layout for a two stroke twin is a parallel twin.
Ditto for a two stroke four it's a square four - RG's and RZ's were squares - anything with 2 crankshafts is a square.

Work out how much this home built will cost.
Go and buy any sprotbike that will outperform it.
Spend the savings on whores and drugs.

[Ixion]

..
Im currently staring into an RGV 250 Crank Case, trying to work out a decent design for transfer ports, might just completely rip off the RGV250 Crank-Case Design, draw up a custom crank and change some of the dimensions to suit the CR500 top ends. Its the transfer ports are whats kinda worrying me, seeing as its a 500 cc cylinder, not a 125, obviously the transfer ports would need to be considerably bigger.

..

Transfer ports are more or less determined by your reed valves, and piston. Bear in mnd that the crank is going to be substantially bigger thana 125 cyclinder crank. Ditto main bearings.

I rather like the idea someone had of joining two CR500 crankcases.

Re V twin versus parallel twin. One problem with big two stroke parallel twins, is that because the crank on a two stroke normally ends up wider than on a four stroke (cos of the centre ebarings and seals,, or labyrinth, the rocking couple gets quite big, which means lots of vibration. The T500, f'instance will vibe your feet of the pegs. And that rocking vibe tends to twist the crankshaft, cos a built up crank can never be as rigid as a forged single piece crank. That leads to all sorts of issues, high cylinder wear and eizure, primary gear noise or failure (a good reason to use a chain or belt primary) . Or, broken crankshafts. V Twin has better inherent balance

[Ixion]

,,,

Work out how much this home built will cost.
Go and buy any sprotbike that will outperform it.
Spend the savings on whores and drugs.

So, where can I buy this two stroke sprots bike ? Huh, huh? Don't need whores or drugs if you've got a two smoker.

[FilthyLuka]

Transfer ports are more or less determined by your reed valves, and piston. Bear in mnd that the crank is going to be substantially bigger thana 125 cyclinder crank. Ditto main bearings.

I rather like the idea someone had of joining two CR500 crankcases.


Joining them left to right or back to front? Cause i suppose we could do the Neander crank trick. Not the two connecting rods but two cranks joined together by a gear on each crank, so they are effectively counter rotating... Although i can see how this could lead to problems in a smoker


Why a V-twin,other than fashion?

Work out how much this home built will cost.
Go and buy any sprotbike that will outperform it.
Spend the savings on whores and drugs.

Why a Vtwin? Because i dont want to have to cast a block to hold two sleeves and because every man and his mutt has a big bore parralel twin stroker.

Go and buy a sprotbike? A traction controlled, four stroke, wide tyred, steering dampened, easy to ride sprot bike that comes off the showroom floor? Id rather have my manic stroker

[FilthyLuka]

Really? So how do you manage the come down then? :lol:

Come down aint so bad, its the flash backs that get ya :cool:

[speedpro]

there was a story on a guy in kiwibiker mag a few years ago.
He used 3? rm250 motors from memory.
I remember he had to cast his own crankcase as the rm ones would not be upto the job. he had a way thicker casing.
Vibration was one of the main problems.
if you want to read it ill scan it and pm it to you if you like.

Jim Steadman, 75deg V3, 3x RM250s. Rumour has it that Dennis Charlott may be doing a few laps on it later in the year at a few chosen meetings.

[speedpro]

IIRC there was a Speedway midget (TQ?) back in the mid-eighties that was a V4 made from 4 YZ465 (may have been 490's) engines. I have the vague recollection that Graham Standring was the driver - or at least involved with the project... but it was a long time ago...

3x IT490s and 1X IT250. Bob Haldane had a hand in it and I thought Bill Buckley was involved as well. They played with firing intervals to see the effect on traction and on the driveline. The "big bang" version was evidently quite interesting.

Don't forget the V8 TZ1000 (4x TZ250s) with the water jackets cut off and fins welded on, in a midget. Big air scoops to the airbox and 8 expansion chambers. When it was in the powerband it flew.

[speedpro]

V2s are good on a 2 smoker especially on BIG ones. Plenty of room for the transfer ports which on a parallel twin would require the barrells to be spaced apart to allow room. The centre bearings can be recessed into the crank webs with the labyrnth seal between them making the whole crank a reasonable length. There would still be a version of the parallel twins rocking vibration but a balancer shaft could take care of a lot of that. Because of the intervals and the duration of the power strokes the clutch and gearbox will only have to ever handle the same peak torque loads as on a single, just that there will be two peaks per engine revolution, therefore a stock standard 500cc 2-stroke gearbox and clutch should be just fine.

Also it is wrong to assume that high primary compression is good. It isn't only the primary compression that "moves" the mixture up the transfers. Primarily it's the partial vacuum in the cylinder caused by the expansion chamber that draws the mixture up. In some cases raising the primary compression, by reducing the crankcase volume, reduces and restricts the amount that can be drawn up into the cylinder actually reducing peak power. Reed valves help here but it's better to have the volume already in the crankcases.

[speedpro]

Rumours are about of a V6 being made with 2 cranks and 6 125cc GP cylinders, either Yamaha TZ or Honda RS. 240hp shouldn't be hard at 14,000rpm. Not bad for a 750. finding somewhere to put the pipes will be the main challenge.

[Coyote]

can ya make me a sv2000s? V4? put two sv engines together?
maybe two tl1000r engines would be better?
Was wondering when someone would mention a V4. That would be great, but I'd much rather be interested in a 2 stroke, turbo'd and fuel injected 2 litre V4 made from 4 KX/CR cylinder heads.

Why a V-twin,other than fashion?
They make so much engineering sense - that's why Rotax don't make one.
The sensible layout for a two stroke twin is a parallel twin.
Ditto for a two stroke four it's a square four - RG's and RZ's were squares - anything with 2 crankshafts is a square.

Work out how much this home built will cost.
Go and buy any sprotbike that will outperform it.
Spend the savings on whores and drugs.
If a cylinder goes bang, you replace the one cylinder rather than the cylinder block. Makes sense when a lot of high performance 2 strokes tend to go bang often.

I agree with Ixion with the whores and drugs thing.

By the way, why does the fuel/oil have to pass through the crank? Has there ever been a wet sump 2 stroke that didn't burn oil?


I'm off to do some porting to my minimoto.

[FilthyLuka]

By the way, why does the fuel/oil have to pass through the crank? Has there ever been a wet sump 2 stroke that didn't burn oil?


I'm off to do some porting to my minimoto.

two stroke deisel? uses exhaust valves and a blower....

[xwhatsit]

If a cylinder goes bang, you replace the one cylinder rather than the cylinder block. Makes sense when a lot of high performance 2 strokes tend to go bang often.

No you don't, you just re-bore the cylinder that got damaged. Or, worst case, put a new liner in for the cylinder that got ferked. Not as though you've got camchains eating the chain tunnel down the side of the block or anything silly like that.

[Pixie]

Best you back away from this thread slowly, and quietly shut the door. You do not, and probably never will, understand. But that's ok, it takes all sorts to make the world go round :)

/edit: Oh, and the RZ500, it is a dual crank V4, not a square 4.

V engines only have one crank - it's a square four.
Do you even know what a square four is?

I probably owned more two strokes than you ever did, several before you were born,I look forward to their return and vanquish of the four stroke world and I recognise a pointless exercise when I see it

PS only an inadequate wanker red reps a post because they disagree with it paLuka

[Pixie]

Was wondering when someone would mention a V4. That would be great, but I'd much rather be interested in a 2 stroke, turbo'd and fuel injected 2 litre V4 made from 4 KX/CR cylinder heads.

If a cylinder goes bang, you replace the one cylinder rather than the cylinder block. Makes sense when a lot of high performance 2 strokes tend to go bang often.

I agree with Ixion with the whores and drugs thing.

By the way, why does the fuel/oil have to pass through the crank? Has there ever been a wet sump 2 stroke that didn't burn oil?


I'm off to do some porting to my minimoto.
Plenty of inline engines have separate cylinder: Deutz Fahr ,SAME

Wet sump two strokes?
stepped piston:

http://users.breathe.com/prhooper/opads.htm

Pivotal from Christchurch ( which is best described as dry sumped or no sumped )

http://www.pivotalengine.com/index.html

And supercharged are possible.

[diesel pig]

By the way, why does the fuel/oil have to pass through the crank? Has there ever been a wet sump 2 stroke that didn't burn oil?

Yeah there is, Detroit Diesels but with no crankcase compression they here big fuck off blowers to get the air into them which brings me to fun fact No 237 2 stroke Detroit Diesel blowers have been turned into superchargers on Top Fuel Dragsters for 50 years.:whocares:

[speedpro]

V engines only have one crank - it's a square four.
Do you even know what a square four is?

I probably owned more two strokes than you ever did, several before you were born,I look forward to their return and vanquish of the four stroke world and I recognise a pointless exercise when I see it

PS only an inadequate wanker red reps a post because they disagree with it paLuka

Yamaha's 500/4 2-stroke is a V4, it even says so on the fairing. Pairs of bores are parallel but each pairs bores are set at an angle to the other pair making a V when viewed from the side. From "motorcycle.com" about the RZ500 - "Inspired by the YZR500 factory racer ridden by Roberts during the 1983 GP season, the twin-crank V4 was the closest thing to a Gran Prix bike (with lights) that you could get your hands on".

Suzuki's 500/4 is a square 4 with 2 cranks, obviously. A friend has turned one into a V4. It still has 2 cranks just the barrels are now in a similar configuration to the Yamaha 500. All 4 carbs are set in a line in the middle of the V.

The number of cranks has nothing to do with it. A V4 could have 1 crank, 2 cranks geared together and contrarotating, or 2 cranks with a jack-shaft between so both cranks rotate in the same direction.

[rudolph]

What about a DKW:shit: SPLIT SINGLE 2 stroke, one cylinder is the compresser, they say it is the loudist thing you have ever hird

[Pixie]

Yamaha's 500/4 2-stroke is a V4, it even says so on the fairing. Pairs of bores are parallel but each pairs bores are set at an angle to the other pair making a V when viewed from the side. From "motorcycle.com" about the RZ500 - "Inspired by the YZR500 factory racer ridden by Roberts during the 1983 GP season, the twin-crank V4 was the closest thing to a Gran Prix bike (with lights) that you could get your hands on".

Suzuki's 500/4 is a square 4 with 2 cranks, obviously. A friend has turned one into a V4. It still has 2 cranks just the barrels are now in a similar configuration to the Yamaha 500. All 4 carbs are set in a line in the middle of the V.

The number of cranks has nothing to do with it. A V4 could have 1 crank, 2 cranks geared together and contrarotating, or 2 cranks with a jack-shaft between so both cranks rotate in the same direction.

The Fact that it has 2 cranks precludes it from being a true V.
They could hardly write "Square four Crank Configuration With Non Parallel banks of Two Cylinders" on the fairing could they?

On a true V pairs of conrods share the same crank pin

Don't put your understanding of engineering in the hands of some ignorant motorcycle journalist.They still don't understand that an engine with a side to side crankshaft and four parallel cylinders is a transverse straight four and one with a fore and aft crankshaft and four parallel cylinders is an inline straight four
Don't try to teach your grandmother to suck eggs

[Ixion]

..
On a true V pairs of conrods share the same crank pin

..

Shit load of car and truck V6 and V8 engines that have different ideas.

[Skunk]

They could hardly write "Square four Crank Configuration With Non Parallel banks of Two Cylinders" on the fairing could they?Just "Square Four" would suffice I think. If it were right that is.
"Isosceles trapezium four" is what you're thinking of - cause square it ain't.

[Ixion]

Firing interval is what would determine if a square four behaved as a V4, two V twins or two parrallel twins or a perverted inline four.

[FilthyLuka]

PS only an inadequate wanker red reps a post because they disagree with it paLuka

hmm "i disapprove..." I disapprove of your outlook on my wee little project, i disapprove of the idea i should just go out and buy a new sports bike and i disapprove of having to tally up the total cost of a build before its starts and spend not a cent more...

I also disapprove of being called an inadequate wanker, hence the red showing said disapproval.



On a true V pairs of conrods share the same crank pin


Wouldn't a two stroke vtwin sharing the same crank pin make it essentially fire like a "big bang" engine? I mean, everytime the piston is at TDC, the spark plug fires and you get a power stroke. So, if two conrods shared the same pin, it would mean both pistons would fire at the same time as they would both be at TDC at the same time, effectively making an expensive single cylinder.

So Aprilia RS, Suzuki RGV and Honda NSR aren't true v-twins...

I suggest you take imdyings advice

[speedpro]

V Engine
One with two banks of in-line cylinders mounted with an angular separation on a common crankcase.

Common crankcase, NOT common crankshaft.

Seems I'm not the only one suffering from a misconception of what constitutes a V configuration engine.

Also direct from the Cagiva website, specifications for the Cagiva C504, as ridden by John Kocinski - "498,3cm3 (56/50,6mm) 80°V4 twin crankshaft". Seems even the dudes designing and building the engines have got it wrong. Just for interest, the cranks in this square four(?) were geared together and contra-rotating.

[xwhatsit]

So, if two conrods shared the same pin, it would mean both pistons would fire at the same time as they would both be at TDC at the same time

Ummm.... no? Not unless the angle between the cylinders was 0 degrees. Which would be hella difficult.

[FilthyLuka]

Ummm.... no? Not unless the angle between the cylinders was 0 degrees. Which would be hella difficult.

#click, brain turns on# oh yeah... Sorry, disregard the post i made before, mind is stuck in single cylinder mode :Oops:

[speedpro]

Wouldn't a two stroke vtwin sharing the same crank pin make it essentially fire like a "big bang" engine?

No. Plus you can't(shouldn't) build a 2-stroke twin with the cylinders displaced about the crankshaft axis sharing a common crankcase as the cylinder port timings will be different by the value of the V angle. The 1st cylinder whose transfer ports open will get the best shot of air/fuel, leaving not much for the 2nd. You could get away with it if air was force-fed direct to the cylinder ports and not via the crankcase. Pretty typical setup for the BIG turbo diesel 2-strokes as in ships etc. They are in-line engines though.

I've toyed with the idea of supplying fuel/air/oil to a manifold over the transfer ports from a little supercharger I have, but time/ money etc will make sure it never happens.


Edit - I type too slow!

[xwhatsit]

mind is stuck in single cylinder mode :Oops:

No sweat, I spend my whole life living there :2thumbsup

[Ocean1]

mind is stuck in single cylinder mode :Oops:


No sweat, I spend my whole life living there :2thumbsup

Nawt wrong wiv 'em I say. Was good enough for Uncle Sylvester and it's good enough for us.

http://www.motorcyclemuseum.org/classics/bike.asp?id=3

[imdying]

V engines only have one crank - it's a square four.
Do you even know what a square four is?/edit: Yes, you're right. The sticker on the side is wrong... two pistons going one way, two the other, it's definitely a square four, my mistake. I will try to insure that in the future I do not misinform other members by providing false information in my posts.

[onearmedbandit]

The Fact that it has 2 cranks precludes it from being a true V.........

V engines only have one crank - it's a square four.
Do you even know what a square four is?

I probably owned more two strokes than you ever did, several before you were born,I look forward to their return and vanquish of the four stroke world and I recognise a pointless exercise when I see it


Pixie, just wondering if this helps clear it up a bit for you?

BTW, if it doesn't, let me know because there is an engineer here in CHCH that designed and built a 500cc V4 dual crank ZXR250 based engine. Now this guy has only built and designed engines, and as you have owned lots of engines you no doubt can correct him as well.

[ManDownUnder]

Pixie, just wondering if this helps clear it up a bit for you?

Na mate - that pics got me beat... can you give us a clue... that final shape... not too sure on it.

Rhomboid?

[pete376403]

No. Plus you can't(shouldn't) build a 2-stroke twin with the cylinders displaced about the crankshaft axis sharing a common crankcase as the cylinder port timings will be different by the value of the V angle. The 1st cylinder whose transfer ports open will get the best shot of air/fuel, leaving not much for the 2nd. You could get away with it if air was force-fed direct to the cylinder ports and not via the crankcase. Pretty typical setup for the BIG turbo diesel 2-strokes as in ships etc. They are in-line engines though.!
Nope - two stroke diesels dont have to be in-line. You must have seen GM 6,8 or 12 cylinder two strokes in Vee configuration, eg 6V71 or 8V71.
And as for a naturally aspirated two stroke, whether inline or V, each cylinder has to have it's own crankcase - it might be a common casting but each chamber is sealed from it's neighbour(s)
The main reason for building a V twin over a parallel twin was to get more room in the cylinders for the transfer ports.

[pete376403]

Yeah there is, Detroit Diesels but with no crankcase compression they here big fuck off blowers to get the air into them which brings me to fun fact No 237 2 stroke Detroit Diesel blowers have been turned into superchargers on Top Fuel Dragsters for 50 years.:whocares:

Detroit Diesel two stroke diesels have four valves per cylinder and IIRC an overhead cam too. (Uniflow design is also used in Nissan UD engines)
The valves are all exhausts and the cam is for the fuel injector (it's been a long time since I had one apart)

[DEATH_INC.]

Just to clear up one little thing, a normally aspirated two stroke cannot share a common crankcase between two cylinders, the reason for this is that the thing that makes it all work is the piston pushing the air/fuel mixture outta the crankcase on it's downwards stroke. This is why you must have a reed valve, a rotary valve or the piston closing off the intake (piston port I think that's called). The amount of crankcase compression is determined by the size of the piston relative to the crankcase size, and the amount of piston travel downwards before the transfer ports open.The capacity of the casing doesn't matter a lot, the area under the piston will take care of the air/fuel you need.

You can't join two CR cases side by side unless you can key the cranks together, a one piece will not be possible as I'm sure the CR cases join vertically, so no way to get the crank in there. Better to make yer own one so you can join it horizontally and have a one piece crank.
Prolly the easiest way is like the RZ500, two cranks one in front of the gearbox and one above it, both driving on to the clutch.(gears on the RZ from memory)
This sounds like a fun project....

[Sollyboy]

There was a rz500 with rz 350 barrels and top ends fitted a few years ago, apparently it was really fast , but being a 2stroke 700 it would be, I love the sound of a big 2 stroke

[speedpro]

I said "Pretty typical setup for the BIG turbo diesel 2-strokes as in ships etc. They are in-line engines though.!"


Nope - two stroke diesels dont have to be in-line. You must have seen GM 6,8 or 12 cylinder two strokes in Vee configuration, eg 6V71 or 8V71.

The engine I saw and was working around was about 3 stories high, in-line 9 cylinders, triple turbo, single exhaust valve per cylinder. You could easily walk down the intake manifold stooped over a bit. All three turbos fed the manifold which in turn fed all 9 cylinders. It had an open crankcase, idled at 2rpm, a redline of 200rpm and max power at 180rpm. The rear 3 cylinders could be run seperately from the other 6 when just moving round in port.

Pretty sure I would have noticed another bank of cylinders.

[speedpro]

What about a flat twin. 2 cranks side by side, geared together so contrarotating and therefore no torque reaction. I'm thinking it would need a counterbalencer to counter the crank forces at right angles to the bores. Pistons would be at TDC at the same time so would balance each other out. sort of like a BMW only better. The crankshafts could be enclosed seperately or together, it wouldn't matter as both pistons would be travelling up or down their respective bores at the same time. Actually probably better seperate just in case of a blow-up. You could even run a 2:1 chamber if room was a problem.

BIG bang 1000cc 2-stroke twin. The transmission could be a problem plus it would need a 90deg turn somewhere.

[Mr. Peanut]

Why don't you just use a jet-ski engine?

[Ixion]

What about a flat twin. 2 cranks side by side, geared together so contrarotating and therefore no torque reaction. I'm thinking it would need a counterbalencer to counter the crank forces at right angles to the bores. Pistons would be at TDC at the same time so would balance each other out. sort of like a BMW only better. The crankshafts could be enclosed seperately or together, it wouldn't matter as both pistons would be travelling up or down their respective bores at the same time. Actually probably better seperate just in case of a blow-up. You could even run a 2:1 chamber if room was a problem.

BIG bang 1000cc 2-stroke twin. The transmission could be a problem plus it would need a 90deg turn somewhere.

One crankcase chamber for two cylinders? How you going to ensure that each transfer port gets half the mixture ?

[Ixion]

I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

[kevfromcoro]

Bit of topic ,,but still bike mods.
Was out the other day ,and spotted a couple of trikes.caught up with the owners .a older man and lady just out riding.
the trikes were both suzuki 1500.
apparently there is a guy in Taupo who converts bikes into trikes.
these were shaft models with a shortened holden diff in them..
looked quite kool accuatly
comfy and lots of room to store your goodies

[Mr. Peanut]

I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

I don't think the British had enough time to make something that idiosyncratic, another 30 years of motorcycle market dominance and who knows? They made the Ariel square snore after all.

Bit of a waste of space? Why not just make a parallel twin.

[Ocean1]

One crankcase chamber for two cylinders? How you going to ensure that each transfer port gets half the mixture ?

Most 4T multi cyl single carb engines seem to manage ok...


I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

What'd be the point? Good curiosity value but it'd be heavy, with the mass at the ends. And bloody long, for/aft mounted?

I built some weird steam toys when I were a nipper, still got a couple burried in the shed somewhere. One's an elbow engine, two six-shooter type rotating magazines mounted at 90deg, with common 90deg bent pistons in each bore pair. Looks bazarre but makes lots of torque, serious revs too.

[DEATH_INC.]

Why don't you just use a jet-ski engine?

I meant to mention it before, guys in the US use big two stroke snowmobile engines...

[Ixion]

We know that. Look, if we wanted PRACTICAL we'd use four strokes .

[DEATH_INC.]

Yeh, I know that :p
Just thought I'd throw it in there.....I'm all for the idea of building something from scratch.
The question is really whether the machinist / designer is up to scratch building and designing a crankcase and crank. With the common-crank twin you'll need to make up cases, with a twin crank you could prolly boogey up something using the cr bits. If you're gonna use a common crank the engine will be nearly as wide as a four as you gotta run two near complete engines side by side, whereas if it's a (what do you call a twin crank v twin again??) it'll be longer or taller. As Speedpro (i think it was ) mentioned a twin crank has the advantage of being able to blow up 1 cylinder/crank and hopefuly salvaging the other....
Personally I'd like to see the single crank option it'll be a more compact engine :)

[speedpro]

One crankcase chamber for two cylinders? How you going to ensure that each transfer port gets half the mixture ?

With the suggested layout both pistons rise in both bores simultaneously, all the transfer ports open simultaneously. In fact EVERYTHING in each cylinder happens simultaneously. Both pistons move out and both pistons move back at the same time, but in opposite directions thus cancelling out any reciprocating forces. The beauty of this arrangement is that the crank would only need to be big and heavy enough to handle engine running forces and there would be no requirement for crank counterbalance. There would be a reasonable imbalance acting perpindicular to the bore's centreline which would need a balance shaft or somesuch to counterbalance.

[Ixion]

Common crank shouldn't need to be much wider than a 4T twin with a centre bearing. Needs the end shafts pressed out of the two cranks, and a common joining shaft machined to join the two together and hold the centre bearings and seals (will be a bit wider than the 4T , cos of the seals, and you really need two bearings not one). Still narrower than a four though.

If one were designing from scratch one could maybe offset the cylinders to make up some of that, but that's a bit hard in a fabricated jobby.

Centre split is much better for this purpose than horizontals split, because the runout tolerances on a centre split with a chain/belt primary drive don't have to be super critical, ball race mains can take up a bit (I'm talking point of a thou here) of misalignment. The old Briddish twins were never truely in line, Ive seen the main bearing housings out by near a millimetre.

Trouble with twin crank engines is , unless you keep them really closely tuned, they end up trying to run at different revs, which causes lots of issues for whatever you are using to connect them.

[speedpro]

I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

Something like that has been built from scratch by a guy Neil Hintz. 2 crankshafts, 4 pistons. It was built as a uniflow engine with both crankcases at one end feeding one cylinder and the crankcases at the other end feeding the other cylinder. Various guises were tried, 2 or 4 carbs, 2 or 4 expansion chambers. Originally built as a bucket engine the first one had brushcutter conrods and would do about 20,000rpm (very short stroke per piston). Later versions were full size 500cc and were used to power a microlight. In each cylinder one piston controlled the transfer ports and the other controlled the exhaust ports. The last engine had smaller exhaust side pistons and there was some differance in the phasing of the pistons in each cylinder.

[Ixion]

If you used a third crankshaft to couple the cranks, you could use that to drive a charging cylinder, like the NSU/Puch split singles.

[speedpro]

If you used a third crankshaft to couple the cranks, you could use that to drive a charging cylinder, like the NSU/Puch split singles.

Trouble with that is that then the cranks are both rotating in the same direction and we have a torque reaction problem.

The concept is good, BMW have a pivoting balancer thing along those lines in one of their new 650(?)cc bikes I think.

[Ixion]

No, if you cross the conrods from the power cranks to the comon crank, the power cranks (ie the ones with pistons) can turn in opposite directions. That's exactly how Dr Fred did it, back in nineteen hundred and diddly. Does mean very long conrods for the connectors, though, which might be a problem with modern day revs.

I think I better get another beer mat, this design is getting complex.

[Mr. Peanut]

Rods, cranks, seals, special pistons...

Bah.

Build a rotary and be done with it.

[Ixion]

Booorrrriinnng.

And they don't go ringa-dinga-ding. Do they, huh ? Huh? Huh?

[FilthyLuka]

Well, reading through the thread (and scribbling down notes something vicious) im starting to get enthusiastic about the project more and more.

So far:

Staying with v-twin. Why? No idea, seems like a good idea... Although my brain seems to be imagining a square twin...

For the crank, seeing as the need to be isolated, im thinking go with the twin, counter rotating cranks joined by gears, going to the gearbox/clutch

So, the crankcase would be effectively be two crankcases joined back to front. Both cylinders would be vertical, but bolted into the same crank case, like an inline engine but the other way, longditudinal if you will. Obviously the bores would be independant of each other, carbs in between the two. The cranks would be two CR500 cranks, running with a bit out of the (random side) right hand side crank case (the section that the crank comes out of will need to be sealed, so the crank doesn't de-pressurize). So, if you took the left crank case cover of, you would see two gears mashing together :) This would be the two cranks.

Do you guys reckon it would be a wise idea to have a set of gears joining the cranks on each side? Or would that just be un-neccesary?

Also, if the gears were running together, there would need to be lubricated. Simplest way to do this is for the gears to have their own sealed chamber on the right hand side of the crank case where one would dump in oil for lubricating purposes. Something tells me that running the gears that would be joining the cranks together un-lubricated would be a bad idea.

The reason i want to keep the gears out side of the main crank case is so that keeping the two chambers of the crank case separate becomes a lot simpler. No gear needs to go in between the two, so each cylinder would have its own pressurized crank, assuring it get the optimal shot of fuel/oil/air mixture every cycle. (I never liked sharing as a child, i might reflect this in the engine design).

If the twin crank idea goes through, the bike will say "VTWIN" on the side just to piss pixie off...

And for some reason the picture of Honda's oval piston featured in the NR-750 keeps coming to mind, one piston, two con-rods, two spark plugs, two intake/exhaust ports... Could be fun to make something that utilizes this design, but too much of a pain in the arse making pistons :S

[pete376403]

I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

You're describing either the Commer TS3 truck engine (3 cyl, 6 piston, 12 con rods and two big rocker shafts. design originally borrowed from Dornier (IIRC) bomber engine of WWII
Or, two strokes taken to taken to the extreme, the Napier Deltic, used originally in british motor torpedo boats then locomotives, and then in the "nasty" class boats used in Vietnam

[DEATH_INC.]

Well, reading through the thread (and scribbling down notes something vicious) im starting to get enthusiastic about the project more and more.

So far:

Staying with v-twin. Why? No idea, seems like a good idea... Although my brain seems to be imagining a square twin...

For the crank, seeing as the need to be isolated, im thinking go with the twin, counter rotating cranks joined by gears, going to the gearbox/clutch

So, the crankcase would be effectively be two crankcases joined back to front. Both cylinders would be vertical, but bolted into the same crank case, like an inline engine but the other way, longditudinal if you will. Obviously the bores would be independant of each other, carbs in between the two. The cranks would be two CR500 cranks, running with a bit out of the (random side) right hand side crank case (the section that the crank comes out of will need to be sealed, so the crank doesn't de-pressurize). So, if you took the left crank case cover of, you would see two gears mashing together :) This would be the two cranks.

Do you guys reckon it would be a wise idea to have a set of gears joining the cranks on each side? Or would that just be un-neccesary?

Also, if the gears were running together, there would need to be lubricated. Simplest way to do this is for the gears to have their own sealed chamber on the right hand side of the crank case where one would dump in oil for lubricating purposes. Something tells me that running the gears that would be joining the cranks together un-lubricated would be a bad idea.

The reason i want to keep the gears out side of the main crank case is so that keeping the two chambers of the crank case separate becomes a lot simpler. No gear needs to go in between the two, so each cylinder would have its own pressurized crank, assuring it get the optimal shot of fuel/oil/air mixture every cycle. (I never liked sharing as a child, i might reflect this in the engine design).

If the twin crank idea goes through, the bike will say "VTWIN" on the side just to piss pixie off...

And for some reason the picture of Honda's oval piston featured in the NR-750 keeps coming to mind, one piston, two con-rods, two spark plugs, two intake/exhaust ports... Could be fun to make something that utilizes this design, but too much of a pain in the arse making pistons :S

Righto, twin cranks then. If you start off with something similar to the CR engine( just as an example to give you the idea), lay the front cylinder forward a bit, then mount the rear crank above the front gearbox shaft ( won't be too tall, no cams 'n shit ) and gear them both straight onto the clutch primary drive(or maybe through an idler). Don't need to be counter rotating if they're in line. Keeps it compact and simple. Oil will of course then come from the gearbox to feed these gears, as per normal. No need for a second set of gears on the other side. I would probably reverse the rear cylinder and piston so that the exhaust comes out the rear or it could be messy, and then you can run both carbs in the middle of the V (out the side anyhoo) with 90 deg manifolds. You MUST keep the crankcases completely separate unless you run both pistons up and down together or it won't work. This is basically how the RZ500 and KR250 are made (prolly others too, but I haven't seen them myself) so is an already proven design.
Get into it :)

[DEATH_INC.]

You're describing either the Commer TS3 truck engine (3 cyl, 6 piston, 12 con rods and two big rocker shafts. design originally borrowed from Dornier (IIRC) bomber engine of WWII
Or, two strokes taken to taken to the extreme, the Napier Deltic, used originally in british motor torpedo boats then locomotives, and then in the "nasty" class boats used in Vietnam
The problem with this idea for a bike engine is you spread the COG to wide, and add more heavy bits too. Mass centralization and lightness is where it's at.

[Ixion]

You're describing either the Commer TS3 truck engine (3 cyl, 6 piston, 12 con rods and two big rocker shafts. design originally borrowed from Dornier (IIRC) bomber engine of WWII
Or, two strokes taken to taken to the extreme, the Napier Deltic, used originally in british motor torpedo boats then locomotives, and then in the "nasty" class boats used in Vietnam

Them was diesels, but, was they not. Diesel is easier. Didn't the Deltic use sleeve valvves. Mr Motu is the expert on the Deltic.

[Motu]

No,I'm a TS3 man.I used to have a Johnson outboard that was a flat twin 2 stroke.Had to be a big bang because that's the only way they can run.....but I always wondered how that arrangement would work with a lot more capacity....and in a bike of course.Two CR500 top ends,double crankcase induction with reed valves...it'd need a special crank,but that's child's play to these young engineers.

[cowpoos]

No,I'm a TS3 man.I used to have a Johnson outboard that was a flat twin 2 stroke.Had to be a big bang because that's the only way they can run.....but I always wondered how that arrangement would work with a lot more capacity....and in a bike of course.Two CR500 top ends,double crankcase induction with reed valves...it'd need a special crank,but that's child's play to these young engineers.
Do you know who made the super charged 10 or 12 rotary cyclinder air cooled two stroke?? was an air craft engine of course!!

[speedpro]

Rotary cylinder or radial??

[cowpoos]

Rotary cylinder or radial??
errr...radial... woops!

[pete376403]

Them was diesels, but, was they not. Diesel is easier. Didn't the Deltic use sleeve valvves. Mr Motu is the expert on the Deltic.
Nope the Deltic used ports in the cylinders to get the gas in and out. Supercharged of course. There was very clever timing of the cranks to get the appropriate ports open at the right time, and two cranks turned one way and the third crank turned the opposite. Check this link to see an animation http://www.wis.co.uk/justin/deltic-engine.html
The deltic (and the TS3) were diesels but now that direct injection of petrol is more manageable, possibly a Petrol fueled deltic could be built.

Getting back to the two cylinder twostroke bike motor, another layout that could be considered is the tandem twin, as used in the Kawasaki KR250 and KR350. Very successful in their day, many World Chams in GP level riiden by kork Ballington. MakAkes a fairly long motor and air colling would be an issue for the rear cylinder. Water would solve most of the cooling issus, and if the cranks were stacked diagonally, the gearbox shafts could be tucked underneath the rear crank (But the the engine become too tall)

[DEATH_INC.]

Getting back to the two cylinder twostroke bike motor, another layout that could be considered is the tandem twin, as used in the Kawasaki KR250 and KR350. Very successful in their day, many World Chams in GP level riiden by kork Ballington. MakAkes a fairly long motor and air colling would be an issue for the rear cylinder. Water would solve most of the cooling issus, and if the cranks were stacked diagonally, the gearbox shafts could be tucked underneath the rear crank (But the the engine become too tall)
That's exactly the layout I've been talking aboot, just with the cylinders angled a bit.....it won't be too tall as it's a 2 stroke, so the extra height from moving the crank up is countered by having no big fourstroke head with cams 'n stuff.....and I'm pretty sure the last aircooled big honda was the 480, so this'll be watercooled.

[F5 Dave]

Rotax Tandem twin would have preceded & outlived those, with same architecture - used for GP bikes (a friend has one) but largely in Karts & snow etc.

[F5 Dave]

Bit of topic ,,but still bike mods.
Was out the other day ,and spotted a couple of trikes.caught up with the owners .a older man and lady just out riding.
the trikes were both suzuki 1500.
apparently there is a guy in Taupo who converts bikes into trikes.
these were shaft models with a shortened holden diff in them..
looked quite kool accuatly
comfy and lots of room to store your goodies

How to destroy a motorcycle & combine a vehicle with all the disadvantages of a car & all the disadvantages of a motorcycle wrapped into a tasteless evil handling aborting of a creation for those who feel that they don't really want to ride a motorcycle any more. Buy a car would be my advice.:zzzz:

Or a van. A least you can get your dirt & race bikes into it.

[Pixie]

I wonder if anyone's ever built a two stroke Lanchester engine?

Horizontally opposed, piston heads facing each other, with the combustion space between them, and a crank at each end . Would have to be big bang firing but the induction and exhaust should work OK. And that would be a BIG bang.

18 cylinder 36 piston twostroke:

[pete376403]

Thats a Deltic.