1000cc in 2012

[Spidey]

legalese. 

<tingly (again)> 

[Spidey]

http://www.superbikeplanet.com/2009/Dec/091211a.htm

Is that it?  Or is that a summary of the rule?  Cuz there's gonna be a big-ass fight if that's all the rules says.  

Edit:  Ah, its' just a general rule so that they can get started on development: 

“The main changes we have decided on are new rules for the MotoGP class,” added FIM President Vito Ippolito. “We will have four-cylinder engines, four-stroke of course, with a 1,000cc maximum. This base will give all the manufacturers the opportunity to start work. At the beginning of next year we will produce the new rules in a more complete format, but that is the basis. 2012 will be the year of a new era of MotoGP.”

http://www.crash.net/motogp/news/155290/1/new_era_for_motogp_as_1000cc_returns_in_2012.html

[derby]

Is that it?  Or is that a summary of the rule?  Cuz there's gonna be a big-ass fight if that's all the rules says.  

http://roadracingworld.com/news/article/?article=38940

[Spidey]

I was asking specifically about the 2012 engine rule.  It looks like they've just laid out the general standards and will get the technical rules in place (like they have for 2010 engines in the RR link) later down the line.

[Speeddog]

Max bore of 81mm, so max stroke 48.5mm.
Bore/stroke ratio of 1.67.

Gonna put the hurt on Ducati, taking weight off of the front wheel...

[Spidey]

Gonna put the hurt on Ducati, taking weight off of the front wheel...

I've heard generally that it's gonna hurt the Duc, but can you 'splain puh-leeze the part about the front wheel?

[Drunken Monkey]

Max bore of 81mm, so max stroke 48.5mm.
Bore/stroke ratio of 1.67.

Gonna put the hurt on Ducati, taking weight off of the front wheel...

Area of the piston is pi * r² so max area is 40.5² x 3.14 or 515mm²

With a max displacement (per cylinder) of 250, that leaves us with a min stroke of 250cm³ / 51.5cm² or 48.5mm

81mm / 48.5 mm gives us a maximum (mightily over-square) bore-stroke ratio of 1.67
(Just checkin' yer maths  )

The current bore/stroke on the 'Sedici (according to Wiki) is 104mm bore, 64.7mm stroke but this can't be right as this gives us a 2 liter engine. Maybe it's for one of their twins...

But at least the ratio is a similar 1.60, so it shouldn't hurt them too much.

[Drunken Monkey]

Hmmm, I also found the more reasonable bore/stroke value of 86x42.56 on the web.

That's 2.02 so I can see that being a big change for them

[Speeddog]

I've heard generally that it's gonna hurt the Duc, but can you 'splain puh-leeze the part about the front wheel?

Longer stroke means the distance from crank centerline to the front of the horizontal cylinder head is bigger.
So, effectively the engine moves back in the chassis.

I can't find a pic of the GP09 engine, so I may be talking out my arse.

[Spidey]

Ah, that makes perfect, simple sense.    I thought it was gonna be a bunch more complicated than that.

[Drunken Monkey]

Ah, that makes perfect, simple sense.    I thought it was gonna be a bunch more complicated than that.

Well, he didn't explain how the shorter stroke results in less space/time drag in the rotating Minkovskian reference sphere, leading to less graviton production around the centralized mass-space.

But his description is good for the lay-person 

On a more serious note: Can anyone explain why they made the bore size restriction? Are they attempting to put a limit on how over-square (and peaky) the motors are? In other words, a round-about way to restrict output to a certain extent.

Or is it yet another 'switch from max 5 cylinders to 4 while conveniently dropping displacement by 20%' giveaway to a certain manufacturer who shall remain nameless (coughHondacough)?

[Speeddog]

Just an easy to enforce rev-limiter, as they've effectively decreed a minimum stroke.

I strongly suspect there will be additional rules prohibiting exotic-material pistons and rods, as that's the 1st engine-builder countermeasure against that kind of restriction to get more revs.

[ducpainter]

Just an easy to enforce rev-limiter, as they've effectively decreed a minimum stroke.

I strongly suspect there will be additional rules prohibiting exotic-material pistons and rods, as that's the 1st engine-builder countermeasure against that kind of restriction to get more revs.

why not just make it another spec class....

like moto 2?

[Drunken Monkey]

why not just make it another spec class....

like moto 2?

Please, never speak of this again. They might be listening.

[Speeddog]

A few more details:
http://www.motomatters.com/news/2009/12/12/more_on_the_motogp_rule_changes_6_engine.html