R21 Hamilton Jet

[Burty]

Originally Posted by NIC SURRY

If my XR2 ever blows it might be a thought

Can you say 'if' when you have an XR2?? more like when

[NIC SURRY]

Originally Posted by Burty

Can you say 'if' when you have an XR2?? more like when

Sooner rather than later if I let you drive it-it does run below 7000 rpm you know!

[Cookee]

Originally Posted by Jon Fuller

I don't think it would lack torque.

A B23 Busa would be a larf. And i'm sure getting round the reverse rule wouldn't be a problem.

I a light enough B23 it would be ok, but anything heavier and the lack of torque would show up, of course a Hyabusa twin rig would sound great, probably give quite a good performance, be very stable and be a right laugh!

[Jon Fuller]

Originally Posted by Cookee

I a light enough B23 it would be ok, but anything heavier and the lack of torque would show up.

John, well, if you're talking from experience, I bow to it.
But if it's just an opinion, as is mine, I disagree. The >1litre bikes, and definitely the >1.2 litre bikes are not short of torque.

Before the fundimental design flaw in Kittens hydro showed, ie, when he first stamped on the throttle, it lurched as if to get on plane, then 'broke away', no lack of grunt at all. It was mearly it's innability to grip that failed it. And that was with a wanky old kwacka 1000 motor.

I would assume building it right down to minimum weight would be easy, so the weight would be decided for you, no choice on extra light B23's.

[Andy B]

the busa makes
peak hp is 150.3hp at 9500rpm
peak torque is 128.0 Nm at 7500rpm

http://www.mcnews.com.au/MotorcycleR...0/bus_dyno.htm

[Jon Fuller]

It's not the actual amount of torque, the gear ratios & prop choice deal with getting that right, it's where the torque curve lays across the rev range and how wide the curve itself is, or to be more precise, how flat it is.

I stand by my comments.

[Andy B]

hi jon,(mr fuller)
i passed no comment, just the facts.
but if i was too i would stand with you on this one,
that is a wall of torque for a motor of that weight!
and having riden one on the road i can tell you that it comes in low down and just keeps building. no flat spots.
blue line is busa line

[Jon Fuller]

Is that crankshaft, or rear wheel hp?

[Cookee]

Originally Posted by Jon Fuller

John, well, if you're talking from experience, I bow to it.
But if it's just an opinion, as is mine, I disagree. The >1litre bikes, and definitely the >1.2 litre bikes are not short of torque.

Before the fundimental design flaw in Kittens hydro showed, ie, when he first stamped on the throttle, it lurched as if to get on plane, then 'broke away', no lack of grunt at all. It was mearly it's innability to grip that failed it. And that was with a wanky old kwacka 1000 motor.

I would assume building it right down to minimum weight would be easy, so the weight would be decided for you, no choice on extra light B23's.

Jon, My experience is a little second hand and based on others experience with bike motors in kit cars, so a little skewed and with your much deeper experience in boats than mine I will bow down to your opinion (I'll try not to get into the habit!).

Bike engined cars tend to need lots of revs to keep them going, and with boats needing torque to perform at their best I may have assumed too much! I think that both bike and rotary engines both have possibilities in smaller and race boats - it maybe just a question of someone doing more research to make it all work well?

[Andy B]

Originally Posted by Jon Fuller

Is that crankshaft, or rear wheel hp?

As it’s an article done by motorcycle news and not the manufacturer i would assume that it was tested on a rolling road, so rear wheel

When the hayabusa was first launched it was capable of nearly 215mph,
(that’s before nanny cant do that got hold of it)
At that speed its biggest problem was aerodynamics! The wind resistance was like putting the front wheel against a wall. Hence the need for all that torque!

http://uk.youtube.com/watch?v=Ifrk6JeCafo

But if that’s not enough you can always buy a plug in and play power commander and depending on which one you go for that will give you up to an extra 25 to 30%

But who would want to do that

[Tony Davis]

Originally Posted by Jon Fuller

I'd love to build a Busa powered 3B boat. .

My mate Lorenzo reckons a Norton is the way to go!

[Jon Fuller]

Originally Posted by Tony Davis

My mate Lorenzo reckons a Norton is the way to go!

I know the lorenzo-mobile had it's problems, but it was great to see someone stray from the well beaten and rather boring track of P16/90Yam, or similar.

A B23-BUSA project would really get my juices going.

[Tony Davis]

yeh, and the nav had a nice bum!

[Jon Fuller]

Originally Posted by Tony Davis

yeh, and the nav had a nice bum!

This I know to be true, and a lovely boat race.

Not like that desparate-Dan driver you liked!!

[Andy B]

A B23-BUSA project would really get my juices going.[/QUOTE]

http://uk.youtube.com/watch?v=p29CDV...eature=related

http://uk.youtube.com/watch?v=i3sMem1RuJ8

[NIC SURRY]

Originally Posted by Jon Fuller

I don't think it would lack torque.

A B23 Busa would be a larf. And i'm sure getting round the reverse rule wouldn't be a problem.

When I did Autograss racing the bike engined cars where just coming into it,in the >1300cc used one engine and two engines connected by chains in the unlimited class's you didn't need reverse,years ago a circuit race car (a very small Suzuki car with a Bike engine) won nearly everthing but to overcome the reverse regulation he used a Starter motor connected to the drive via a dog gear-they only had to reverse one yard to pass the regulation,something similar would suffice for a boat I would have thought.Most of the Caterham type cars with bike engines have the prop shaft connected direct to the gearbox output shaft back to a diff (North -South engine lay out)where as the single seaters use the chain drive (East-West)via a diff with reverse built in.the advantage of chain drive is you can easily change sprockets to alter gearing.I suppose if you were using surface drive something like a Arneson type setup would do the job if you could manufacture a Dinky set up

[Andy B]

If sort term reversing was all you needed there is a much simpler answer,
I may be wrong but Honda goldwings have a set-up where you engage first gear and push a button to reverse the electrical polarity across the starter motor, as a result backwards motion! (engine kill switch on)

[wiggy808]

Didn't notice this thread!

I used to turbocharge Busa's for a living whilst working for a company called 'Holeshot Racing', mainly for the kit car industry but also for drag racers and top speed competitors. We held the UK land speed record for a while @ 257mph both directions.

That was running a Garrett GT35R, carillos, JE's etc,and had 788bhp @ 11000rpm and 460lb/ft @ 7000rpm, at the wheel. That enough torque for ya?

There have been arguments for years about the amount of torque produced by Busas and wether it's enough for kit cars. Having been in this industry for years, I can say that it completely depends on the application. If the car is track based and live all its life at 8000rpm plus then the torque figure is irrelevant, it's the power figure you're feeling up there. If the car is going to be used on the road with a passenger then, no there not ideal.

That said, I think for a race boat application it would work very well. Look at it this way, you're not going to be below 8000/9000 when they redline at 12000 are you.

Take a look at the vids below, these are my engines.

http://uk.youtube.com/watch?v=06a-WsZUJvs

http://uk.youtube.com/watch?v=aQO0Hx...ext=1&index=15

If you need any info on 'Busas' give me a shout.

Chris.