Motorcycle Racing Forum

Please let me know if you currently have a Middleweight SuperSport or Sportbike machine with a 1 MM overbore or are currently building.

Well.  Looks like we were planning to start on one for Daytona.  Why? Going a different direction???

i don't personally know of anyone that bothers with 1mm overbore. They go straight to 2mm overbore .. obviously not ss legal.
It's simply cheaper to buy a good used set of cases, than it is to spend $600 on overbore and replate (not to mention the expensive overbore pistons).

Overbore???  Christ, I'm just trying to save for tires at this point.....

Most of the guys here dont touch the motors. Thinner headgasket, degreed cams, and race fuel. OOOOH THAT SWEET RACEFUEL! :) +suspension and race body. Lets face it!..we are low budget racers.. most of us barely afford the tires and the race registrations+all the additional costs /travel, gate fees, ELECTRIC-thanks for NJMP..../
The guys with 1-2mm overbore have alot of advantage especially Daytona. Passing you in the main straight like you are nothing.  If you are not a dummy you can see right away who has motor work done /cheater motors we called/ We all know who they are... but everybody keep they mouth shot. That is our unwritten rule.
Also everybody knows CCS/ASRA officials cannot enforce the rules. We cannot tear our engines apart after each races to have them inspected....
So we just close our eyes and try to have much fun we can possibly have. So 1mm overbore as Greg said really dont worth it... 

I think that 1mm bigger pistons that are used because your cylinder is worn out so stock size won't work anymore.2mm is for superbike engine build.

2mm I need all the horses until Charlie protest my 3rd place finish .    Lol

Charlie protest you????? LOL LOL LOL LOL  :lmao:

^^^^  Zoli   ^^^^   :lmao: :lmao: :lmao:


So true though... it takes more nerve for Charlie to protest ANYONE than it does to race with him on the track...and that's saying something.

Quote from: apriliaman on December 11, 2014, 08:00:08 PM
I think that 1mm bigger pistons that are used because your cylinder is worn out so stock size won't work anymore.2mm is for superbike engine build.

considering the cost of bore/replate Mark, i don't know of anyone that does this (in the supersport classes). You locate a used set of good cases on Ebay, and buy inexpensive OEM pistons. CP aftermarket pistons are upward of $200 EACH, vs. $50-60 each for OEM pistons..

Building a 2mm (or more) superbike motor is a different story.. you are looking to go big time increase, with porting too, and some even going all the way with kit cams. But spending $1500-2000 just on a rebore and 1mm pistons (cause you can't do porting in ss class) is a bit of a stretch for most rider's budget.

How is the enforcement going to work for the 200?

I thought CCS now has a bore / stroke tool that goes right into the spark plug hole? Should make these protests pretty simple.

If you are not protesting known cheaters, well, how can you blame CCS? In my experience they take protests pretty seriously. I've seen them DQ people plenty of times.

 At most tracks there would not be that much of a advantage with 1mm over, however at Daytona there will be. a couple horses or ft lbs if tq make a difference on that banking. Kinda suck cause if I am buying pistons, boring and plating I would rather go 2mm. Anyway good job CCS for pulling this off.

i think they ruled that you can't do 1mm overbore for the 200. Am i mistaken?

Quote from: MELK-MAN on December 16, 2014, 11:54:16 AM
i think they ruled that you can't do 1mm overbore for the 200. Am i mistaken?

This survey and inquiries to engine builders and piston manufacturers is being done to investigate change to rules that currently allow 1mm overbore upto class displacement limits.

When will decision be final

Jan 5 for all rules but will try to get word out sooner if possible.

As long as the Kawasaki 636 is legal I don't see why you would ban +1mm overbores up to class limits.