VT250 v-charge potential?

[bogan]

For a while I've been intrigued by the idea of using one cylinder to supercharge another. Since I've got a VT250F2 I don't use, figured I could sleeve down a cylinder to 100cc, then use the other 125cc cylinder to force feed it. Would need to get new cams or swap a head for reed valves, sleeve and machine a new piston with the right weight, plus the plenum and efi etc.

Thoughts? Would it even meet the rules?

[BASS-TREBLE]

Not sure about the rules etc but have a read of this if you haven't already, very interesting read.
http://www.customfighters.com/forums/showthread.php?t=39520

[Grumph]

Hard to do well and it'd finish up pretty heavy with a lot of internal friction.

IMO a better scheme - but not so glamorous - is to remove one cylinder and bore the other to 150cc.

Four valve head, short stroke - and a plain bearing bottom end.

[Henk]

Sleeve the working cylinder down to 100 and yep, you'd be legal.

[bogan]

Hard to do well and it'd finish up pretty heavy with a lot of internal friction.

IMO a better scheme - but not so glamorous - is to remove one cylinder and bore the other to 150cc.

Four valve head, short stroke - and a plain bearing bottom end.

Wouldn't going from a twin to single bugger up the engine balance? I'm in it for the glamor rather than the performance anyway ;)

[bogan]

Sleeve the working cylinder down to 100 and yep, you'd be legal.

And as far as fabricating parts, anything goes as long as it didn't start as a race part?

[richban]

Hard to do well and it'd finish up pretty heavy with a lot of internal friction.

IMO a better scheme - but not so glamorous - is to remove one cylinder and bore the other to 150cc.

Four valve head, short stroke - and a plain bearing bottom end.



Where do you get a plain bearing short rod. Like for instance one that would fit into an FXR.

[Moooools]

Hard to do well and it'd finish up pretty heavy with a lot of internal friction.

IMO a better scheme - but not so glamorous - is to remove one cylinder and bore the other to 150cc.

Four valve head, short stroke - and a plain bearing bottom end.

I have one of those in the unfinished pile.

Has been bored. New piston so is now 141cc. Balance weight on the crank of 91g made from 4140(just to mimic the rotating part of the missing conrod. Balance factor might still be on the piss). Has a blanking plate for the missing head. All tidy but the bore is a little tight I think.

If anybody feels like making their lives incredibly difficult then make me an offer. Any offer considered.

[jasonu]

I have one of those in the unfinished pile.

Has been bored. New piston so is now 141cc. Balance weight on the crank of 91g made from 4140(just to mimic the rotating part of the missing conrod. Balance factor might still be on the piss). Has a blanking plate for the missing head. All tidy but the bore is a little tight I think.

If anybody feels like making their lives incredibly difficult then make me an offer. Any offer considered.

Sounds like you are building your own mini Ducati SuperMono.

[Grumph]

Where do you get a plain bearing short rod. Like for instance one that would fit into an FXR.

Off the cuff, Rich, early CBR600 Honda is within a MM or so of the right length. can't remember the s/e size sorry.

If you want to find something trick, Bob Densem is importing rods with his own branding. Carillo replicas which look pretty good.
Worth a ring to Denco to see if he's got anything the right length.

That converted VT250 mentioned above would certainly be a good start point for someone. Balance will be close as is.

Never yet met a bucket racer who wasn't in it for the glamour......and fame of course....

[F5 Dave]

Sounds like competition parts. Apart from the CBR, that sounds real legal.

[Drew]

Off the cuff, Rich, early CBR600 Honda is within a MM or so of the right length. can't remember the s/e size sorry.

If you want to find something trick, Bob Densem is importing rods with his own branding. Carillo replicas which look pretty good.
Worth a ring to Denco to see if he's got anything the right length.

That converted VT250 mentioned above would certainly be a good start point for someone. Balance will be close as is.

Never yet met a bucket racer who wasn't in it for the glamour......and fame of course....

What about stroke length. Be awesome if one was lucky enough to simply give it a bore, and Chuck a CBR rod and slug straight in.

[Phantom Limb]

The concept worked great on this Ducati:

http://thekneeslider.com/archives/2009/01/12/ducati-v-one-twin-to-supercharged-single-conversion/

Even has a pressurized tank under the seat that is charged when the bike decelerates to be used later for an extra boost!

[Drew]

The concept worked great on this Ducati:

http://thekneeslider.com/archives/2009/01/12/ducati-v-one-twin-to-supercharged-single-conversion/

Even has a pressurized tank under the seat that is charged when the bike decelerates to be used later for an extra boost!Being three times the capacity of the 'bucket' version, it has something resembling torque to carry all the added weight.

[bogan]

Sounds like competition parts. Apart from the CBR, that sounds real legal.

You talking about the thread topic or the sidetrack?

[Drew]

You talking about the thread topic or the sidetrack?He's talking about the conrods. Bring them in, start an auction on trademe labeling them as an after market replacement for standard parts, and Bob's your uncle, they're legal.

[Grumph]

He's talking about the conrods. Bring them in, start an auction on trademe labeling them as an after market replacement for standard parts, and Bob's your uncle, they're legal.

Bob is of course marketing them as replacements for OE pieces in road motors....doesn't have to be on trademe.

If Bob Densem was your uncle, your attitude toward some other people would have been "adjusted" very early on....

[F5 Dave]

Yeah your VT idea is totally legal as far as I can see.


but to stick the knife in, and why not, this is KB, I would propose it as likely to be finished as, say an electric bucket?;)

[bogan]

Yeah your VT idea is totally legal as far as I can see.


but to stick the knife in, and why not, this is KB, I would propose it as likely to be finished as, say an electric bucket?;)

Sweet

hahaha, well it made it to page two before that was mentioned, bit furthur than I expected. And technically the electric bucket was finished, it was just far too slow to bring to race day...

[Mental Trousers]

Never yet met a bucket racer who wasn't in it for the glamour......and fame of course....

You forgot the women.

[Drew]

Bob is of course marketing them as replacements for OE pieces in road motors....doesn't have to be on trademe.

If Bob Densem was your uncle, your attitude toward some other people would have been "adjusted" very early on....Oh sweet. They aren't marketed as race bits, legal beagle.

If you say so re the attitude, I don't particularly give a shit who I fuck off on here. I'm sure there are a few like yourself who would just like to share a wealth of knowledge and skill, but most are just like me. Know nothings who figure we're right if we just talk the loudest.

[koba]

Also worth noting that piston choice is open, they can be competition parts.

[richban]

Say you got the same hp per litre as Ducati dude, 200 per. You will still only be making 20hp from a heavy piece of crap. Unless you can make 300hp per litre why bother. Even then you would only be at the level of a top 2 stroke bucket and again the weight of the engine would make it a dog in comparison.

Why not sell all the VT bits and buy a proper engine.

[Bert]

Say you got the same hp per litre as Ducati dude, 200 per. You will still only be making 20hp from a heavy piece of crap. Unless you can make 300hp per litre why bother. Even then you would only be at the level of a top 2 stroke bucket and again the weight of the engine would make it a dog in comparison.

Why not sell all the VT bits and buy a proper engine.

Harsh but possibly fair... What's wrong with 20hp :motu:

[bogan]

Say you got the same hp per litre as Ducati dude, 200 per. You will still only be making 20hp from a heavy piece of crap. Unless you can make 300hp per litre why bother. Even then you would only be at the level of a top 2 stroke bucket and again the weight of the engine would make it a dog in comparison.

Why not sell all the VT bits and buy a proper engine.

How will I know if it's 20 or 30 unless I try?

First and foremost its a neat engineering project for me to do, having an application just adds to the challenge and fun, regardless of if it is fast enough to be raced or not.

[richban]

What's wrong with 20hp :motu:

Its not 30!

[Henk]

Its not 30!

Get more cubes

[speedpro]

Works for Richban

[richban]

Works for Richban

That's one beer you owe me on Saturday mike. Could not help yourself could you.

[speedpro]

As much as I was looking forward to the 2-hour, and maybe even buying you a beer, I'm actually going to be in Palmerston North at a nephew's wedding. His wife (to be) wasn't keen on rescheduling the wedding.

[richban]

As much as I was looking forward to the 2-hour, and maybe even buying you a beer, I'm actually going to be in Palmerston North at a nephew's wedding. His wife (to be) wasn't keen on rescheduling the wedding.

Bugger. Tokoroa then.

[speedpro]

Son and I will both be there. Love the whole track, planes, racing, camping, drinking thing.

[bogan]

Well I took it all apart, horizontally split cases are not fun to work on...

The damages, all four camshafts have fucked journals, on both the heads and the shafts. Crank pin is also worn. And thats only under a brief eyecrometer inspection as I was pulling it to bits, may be more damages.

I'm thinking it'd be much wiser to put this project on hold, and get a Spada or something in decent nick to start with. Would get a nicer frame that way too.