Would you give up your Thou' for an 800cc MotoGP rep?

[cowpoos]

Intrinsically 2 pairs of parallel twins bolted together. This, so I'm led to believe, increases the available of torque from the smaller displacement engine -

No...but what that would do is increase the vibrations by a large amount!!! lol

I think what your trying to discribe is the firing order of the inline fours?? 4 cyclinders in a row...the firing order of a number of race inline fours currently in and have been in MotoGP has been firing two cyclinders at a time..by having a rather interesting crankshaft installed...which simulates then firing order of a twin cyclinder engine...most likely a 90 degree V twin...this is a brillent firing order to aid in traction as it gives a larger gap in time between power pulse's for the rear tyre to re-gain traction....while still alowing for the higher air flowing advantages of the inline 4....

[cowpoos]

What I'm interested in is if the manufacturers brought out a crop of 800cc MotoGP replicas would you give up your equally developed 1000cc bike? Part of the appeal to me of the thou is the torque curve, and the way I see it if they brought out an 800cc bike with the same peak power it would not have the spread of torque the 1000cc bike would have. Or am I wrong?

Thoughts please.

(btw, I'm bringing imdyings and my posts across from the other thread.)

Well it depends directly how the engines tuned to behonest...there is no reason why a motorcycle company can't release a 800cc engine with the same power output...at the same rev's as a thou...and a bigger torque curve as its been called in this thread...[which I'm guessing is how you guys are discribing power at mid range rev's and lower???]...they just at this stage have no need to...or don't want to...as its not out of the techinlogical grasp of of any of the big companies really!!

I guess the main advantage of a 800cc sports bike would be one of weight...weight that lays in the reciprocating mass of all the moving parts...would make side to side transitions quicker...and braking quicker...the engines would theotetically rev fast as they have less mass in the pistons,conrods,crank,etc to suck horse power away from its intended source [the rear wheel of course of course]..probally lower diameter fork sanchtions [less stiction]..and possibly lighter in weight...

I would probally seriously consider buying one...I currently have a K4 750 bored-out 812cc GSX-R...it has a hell of a massive motor on it...as fast as a stock thou in a straight line...possibly more once it gets a tune...its an exciting thing to ride...bloody easy to wheelie [will hoist the front off the throttle in 4th gear with near stock gearing...1 tooth down at the front]..and it has plenty of grunt [torque or low and mid range power...what ever you want to call it]everywhere to satisfy anyone!! IMHO

[BIGBOSSMAN]

Don't know whether this has been mentioned, but Honda had the NR750 back in '92. I saw only one on the road here, an oval pistoned 750cc fuel injected statement of V4 engineering. Loosely based on their endurance racer (Le Mans etc), it is the most expensive road bike the company has ever built ($54000 - 5000000 yen).

[rwh]

... they can't do a true rep using the GP stuff, cause that breaks ALL the prototype only laws for MotoGP.

...

What wold be REAL trick would be a track-day/race ready bike sold, that doesnt have to comply to emmision laws, or have the ability to ride slowly on the road, and in variying conditions...a bike that would be delivered on slicks or race tyres, with a race set up, and cast iorn at least brakes, lightweight rims that dont need to be strenthed for going up and down curbs...

Is a semi-mass-produced track bike sharing bits with the GP bike legit in terms of the rules? Is it only road-legal bikes they care about?

Richard

[BIGBOSSMAN]

No...but what that would do is increase the vibrations by a large amount!!! lol

I think what your trying to discribe is the firing order of the inline fours?? 4 cyclinders in a row...the firing order of a number of race inline fours currently in and have been in MotoGP has been firing two cyclinders at a time..by having a rather interesting crankshaft installed...which simulates then firing order of a twin cyclinder engine...most likely a 90 degree V twin...this is a brillent firing order to aid in traction as it gives a larger gap in time between power pulse's for the rear tyre to re-gain traction....while still alowing for the higher air flowing advantages of the inline 4....

Thanks for that Poos, this obviously accounts for the Motogp bikes V-4 like growl instead of the usual screaming note from conventional inline four engines.

[JayRacer37]

nope...kawas are inline4's bro...kawa was in 990cc form a bigbang inline so may have sounded like a V4 to some??

HAH - too slow Poos, i've been corrected already

[JayRacer37]

Is a semi-mass-produced track bike sharing bits with the GP bike legit in terms of the rules? Is it only road-legal bikes they care about?

Richard

Well, it doesn't become mass produced till it is sold as a road bike....theretically, Ducati Desomsedici RR is now homologated for WSB if they wanted too...but if they had sold it without lights, as a race bike...then no rules broken...Like in WSB, Ducati had to sell R models on the road to race them, even tho there were hundereds of RS models adapted from R's and sold as track bikes for WSB and international racing series.

[JayRacer37]

Ever-so-slightly realted: what advantage is a V4 going to give over a V-twin? ...other than fuel flow characteristics in a smaller cylinder maybe?

You get the 'pulse power' and traction of a V-twin, with the outright horsepower of a four cyl.

[onearmedbandit]

a bigger torque curve as its been called in this thread...[which I'm guessing is how you guys are discribing power at mid range rev's and lower???]...

Power is nothing without torque, and with less torque your engine has to work harder to get to the revs that produce the peak power. So torque is the main component I am referring to.

[cowpoos]

Power is nothing without torque, and with less torque your engine has to work harder to get to the revs that produce the peak power. So torque is the main component I am referring to.

yes...power is just a calculation of torque x rev's...torque is the force the engine produces...but power is the result of multipling torque in a time frame...so Revs per min is the time frame we measure everything by in reguard to engine output...and power is the measurement in which its done by... they are to separate things...and seem to be describe as one thing all the time... how discriptive is it if I said...my engine has low high rev torque?? it wouldn't be relitive at all to how much force [power] it will be generating at at high revs would it?

[onearmedbandit]

Stop being difficult, you know what I am saying!!! At the start of this thread I talked of the two bikes having the same power output, now general rule of thumb is that for less cc producing the same power the engine will be 'peakier', ie having the peak power and torque at higher positions in the rev range. Moving the peak torque figure up the rev range will have the effect of making the bike 'slower' at accelerating from lower rev's..

Well from my experience, and from what I've read.

[cowpoos]

Stop being difficult, you know what I am saying!!! At the start of this thread I talked of the two bikes having the same power output, now general rule of thumb is that for less cc producing the same power the engine will be 'peakier', ie having the peak power and torque at higher positions in the rev range. Moving the peak torque figure up the rev range will have the effect of making the bike 'slower' at accelerating from lower rev's..

Well from my experience, and from what I've read.

I was mainly correct the loosly used terms that everyone uses on here and everywhere...but anyway...moving peak torque further up the rev range can and just as easily make a bike faster accerlerating...it depends entirely on how the bike engine it tuned...without genralisations...high horse power is a result of being able to flow high volumes of air,higher into the rev range.... but its totally dependent on tuning...

[Sanx]

Further to what Cowpoos said:

Engine power (hp) = [engine speed (rpm) * torque (ft/lb)] / 5252

As an engine's power is a product of the torque it produces and the engine speed, it's possible to have engines that produce high torque at low revs (Harleys, for instance) that still have a relatively low peak power output.

Roughly speaking, acceleration = torque / weight. If all other things are equal, a bike making 100 ft/lbs of torque at 2000 rpm will accelerate as fast as a bike making 100ft/lbs at 8000rpm. The top-speed of a bike though is generally determined by the peak power of the bike and its aerodynamics.

[speed63]

For the road the 1000 (no replacement for displacement). Now if it was for the track, give me the 800

[codgyoleracer]

Unless superbike pulls back the CC limit - I dont see it happening in the near future. The psychie of the general public & the good ole U S of A is that bigger is better......... (plus a few women ivé known in the past)
No doubt an 800cc/155kg bike would be pretty handy to have though.........Just make it a V4 two stroke & you can have 140kg & still keep the 200hp....... OMG