Production Motorcycle Displacement Size

[equimania]

I recently asked Wink if it is permissible to
up-size a motor above the maximum allowed for
a particular class and run the Production
class of the new motor size (assuming you
otherwise meet all the Production criteria --
i.e., it "appears identical" to a showroom stock
vehicle).  I thought this was an interesting
question and did not seem to be addressed in the
rules.  I can see both sides of the issue and
just wanted clarity.

So as not to keep you in suspense, his answer was
simply no, without a lot of explanation or
justification.

Any thoughts on this?

Below is my original inquiry and his reply, in
full:

Mark's inquiry:

"I have a rules interpretation question regarding Production rules for motorcycles.  I hope I am addressing this to the right forum.  If not, please forgive me and forward this to the correct person.

"Can one take a truly stock bike (assuming otherwise meeting all the Production criteria), and bore and/or stroke the motor to above the original class limit displacement and run in the next higher class?  To give you a specific context for the question, I have a Cagiva Mito 125cc bike that ran to a record in P/P125 class at Speed Week this year.  I am considering installing a commercially available bore kit that will increase the motor size to 163cc and running it in P/P175 class.  This is an aftermarket kit, not made by the manufacturer and never available as a dealer option.  The kit is, however, based on stock parts (molds?) and is "identical" in outward appearance to the stock barrel and head.

"This would seem to be permitted by the rules, but since the bike was never produced  by the manufacturer as other than a 125cc, I had some lingering doubt and just wanted a clarification.  I hope I have given you all the information you need to address this question.  If not please feel free to contact me at this email address for any additional information.

"Thanks for your attention to this, and I look forward to your answer."


Wink's answer:

"you will not be able to run that combo.  sorry."

[joea]

sorry you will not be able to run that
combo in production class

Joe  

[yamagamma]

The production rules don't allow that.
See: 7.J.1 ENGINE CLASSES - PRODUCTION
"OEM engine displacement determines the displacement class for competition. Displacement may NOT be increased beyond that class limit"

[equimania]

Well, that's pretty clear, isn't it?  I don't know how I missed that. As Gilda used to say, NEVER MIND.

Mark (red-faced)

[Seldom Seen Slim]

Well, hey, but I thought. . .

For instance, I thought that I could get a Kawasaki ZX6R with the 636 cc motor and increase displacement to 650 cc and still run it in production.  This is different from Mark's idea -- he's considering putting in a non-production kit to increase displacement -- I wanted to keep the production metalwork and just remove some of it/remove production crank and install stroker.  Maybe the difference is that I would remain in the same class as the stock bike where Mark would be moving to a non-stock displacement class.

Minor difference, hey, and I've never gone through the effort to query the officials to see if my idea would be acceptable -- but I've received unofficial approval from the orange-hat crew for this idea.  

Any comments, boys and girls?

[Larry Forstall]

SSS: You are allowed to increase the displacement of a production bike up to the next class break. Been doing it for years. Most production rules are aimed at "stock external appearance". L

[joea]

you dont have to have any stock internals or dimensions in a "stock" class engine............

Joe  
 
 <small>[ October 30, 2004, 01:12 PM: Message edited by: joea ]</small>

[firemanjim]

Don't have rulebook here at work,but I thought that there was a specific limit on O/S in production class, it was not alot.
Unlike the O/S rules for mnodified.Seems like it was just enough to clean up a cylinder---

[equimania]

Jon (Slim) -- Yeah, what Larry said.  You don't have to stick with the OEM bore OR stroke, but you have to have A bore and A stroke that yields not more than the maximum class size (plus .020 over in classes other than Production).

(But then again, why should you listen to me? I already proved I can't read the rulebook)

Mark