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Hi lads, Does anyone know where I could get my hands on a 440 big bore kit.
If anyone knows of a company that does them or if there's one for sale let me know please!

Thanks

Hope you're not one of the lads running in the Scottish championship!! I had my 1st race meeting a few weeks ago and was disapointed to hear some of the regulars are grumbling about cheating, ie.440 engines being run in the production class.......

It`s the same at every club mate, they should limit F400 to 70bhp in every club across the country. Just like minitwins do with the 72bhp limit.

Hi i run in the scottish production championship and to my knowledge there might be one person running a big bore kit, but not 100% sure.
You could always pay the money to have the engine checked, see Dougie

We have the same amount of whinging here in Oz, yet no-one has put up the dollars to protest. Mind you there are a couple of zxr's that are bloody fast!
I am currently researching if it is leagal here to run 0.5 oversize. Our GCR's say 2% tollerance, which I guess is 408cc, a 0.5 kit by my calculations would be 406cc making it within tollerance but I want this officially confirmed first.
Cheers.

A 2% tolerance on bore size will allow up to approx 412cc, so a +1mm piston can be used

Sorry I should have stated that the tollerance is for "engine capacity" not just bore size. eg, a 100cc could be 102cc.

It would'nt be a number 14 would it??? That is currently on ebay....Maybe he's selling it because everyones on to him...!

Just a quick one ballsout you say you can use 1mm oversize pistons but in the rules it states its on the maximum rebore to the manufactors rebore size (.50) only, not the engine capactiy, so if you put 1mm ones in it's illegal ? Stu

stu71 wrote:Just a quick one ballsout you say you can use 1mm oversize pistons but in the rules it states its on the maximum rebore to the manufactors rebore size (.50) only, not the engine capactiy, so if you put 1mm ones in it's illegal ? Stu

I didn't say 'you can use', Duane was talking about his series allowing a 2% tolerance, I read that asbore size, he corrected me saying it was on capacity. You're right, where rules only allow a manufacturers overbore, the ZXR400 is +.5mm, the FZR400s will be +1mm and the Honda 400s nothing. Bemsee SBK400 rules for 2006/7 allowed a 2% tolerance on bore size which effectively allowed all the 400s similar maximum allowances as the manufactueres allowance for the FZR of +1mm, thus trying to make it 'fair' for all 400 irrespective of the manufacturer (and stop the moaning ) There are now +1mm pistons available for the ZXR400, but they really make very little difference to peak power and affect the tuned engines in other ways

lol not moaning just wanted to make sure there wasn't a loop hole in the rules

Not suggesting you were moaning, just explaining it all in detail so you understand the possible rules from different series

EDIT, while I'm at it, why on earth is someone asking about 440 kits in a racing forum, I can't speak for racing outside of the UK, but I'm pretty sure there is no class of 400 racing that allows 440cc in the UK ???

PS, I know for sure that there have been some 440cc race bikes out there though :smt013

Ballsout Racing wrote:Not suggesting you were moaning, just explaining it all in detail so you understand the possible rules from different series

EDIT, while I'm at it, why on earth is someone asking about 440 kits in a racing forum, I can't speak for racing outside of the UK, but I'm pretty sure there is no class of 400 racing that allows 440cc in the UK ???

PS, I know for sure that there have been some 440cc race bikes out there though :smt013

And i thank you for explaining it to me Balls (thats where my brain is half the time)
Here's a little idea when i did autograss racing (cars) if they thought you was cheating you could put the money up for a set of gaskets and the cost of someone stripping the head off it, it was all marked up at the track, and if you was found to be illegal the owner had to pay the money for the stripdown and banned for 2 years, now i know that is a bit extreme but everyone strips there engines down at the end of the season for a refresh (normally) so if it was maked up with a dremmel it would last till then, and if they said oh it went missing or something daft, they would automaticly get a year ban ? (like drug test in athletics) P.S. i come secound in class one year, and the following year he did get banned with the same car B*****D lol
Stu

I regularly race against a Honda with a big bore kit.

I don't mind though, because i keep beating him.