Post-Classic rules on engine swapping

[cahoots]

Pre 89 class racing, is it legal to put say a cbr 400 motor into a fzr 400 frame ? (All components are pre 89)

[Kickaha]

Pre 89 class racing, is it legal to put say a cbr 400 motor into a fzr 400 frame ? (All components are pre 89)

I would have thought you would have to prove that it had been done "back in the day"

[Grumph]

Don't see why not...it could have been done in the period. I know of a 500 Kawa motor in an FZR chassis done in period.

That said, the opposite ie, Yamaha motor in CBR frame would have been more likely as there were a LOT of CBR400's with dropped valves around the place.....

[mossy1200]

http://www.nzpostclassics.org.nz/ind...r=NZPCRA_Rules

motor transplants ok as long as fit rules

fzr400 with fzr 600 motor etc

Forks are a touchy topic and swingarm mods
as long as your carby(period or replica of period), running pre89 motor in a pre89 frame and the forks and swingarm match the frame should be ok.Eg fzr frame usd zxr400 forks wouldnt be accepted even if they are pre89.

[codgyoleracer]

http://www.nzpostclassics.org.nz/ind...r=NZPCRA_Rules

motor transplants ok as long as fit rules

fzr400 with fzr 600 motor etc

Forks are a touchy topic and swingarm mods
as long as your carby(period or replica of period), running pre89 motor in a pre89 frame and the forks and swingarm match the frame should be ok.Eg fzr frame usd zxr400 forks wouldnt be accepted even if they are pre89.

As Mossey says, where there are specific rules about specific components (that must match the oiginal bike E.G USD forks, Injection etc), then thats where you would need to be carefull.
I have never seen a rule stating :if you could do it in the day then you can do it now", as i suspect that one could be streeeeetched. Never-the-less, as ageneral guidline IMO its mostly rings true.
GW

[Billy]

As Mossey says, where there are specific rules about specific components (that must match the oiginal bike E.G USD forks, Injection etc), then thats where you would need to be carefull.
I have never seen a rule stating :if you could do it in the day then you can do it now", as i suspect that one could be streeeeetched. Never-the-less, as ageneral guidline IMO its mostly rings true.
GW

Try me !!!!!

[cahoots]

So interpretation. If you kept the componentry true to the frame, and only changed the engine (even to a different breed), that would be okay?
Does anyone know if there is a section in rules dealing specifically with engine swapping?
ps Well done in the weekend Glen

[malcy25]

So interpretation. If you kept the componentry true to the frame, and only changed the engine (even to a different breed), that would be okay?
Does anyone know if there is a section in rules dealing specifically with engine swapping?
ps Well done in the weekend Glen

Chapter 25 on the MNZ website. Have a really good read, it should explain most things.

[Grumph]

In the pre 89 period, F3 and F2 were pretty much open GP style classes. Stay under the engine capacity rules and you were OK.

i saw a number of specials using the Kawa 500 motor in various frames, singles were put into a wide variety of chassis.
One thing which will get attention is making your CBR a 450...up to F2 you go sir...Unless it's already a 600 CBR ? In which case I know of a 600/400 frame hybrid done in period in NZ.

There is no specific set of rules relating to engine swaps - read Motorcycles Technical in the MNZ rules, build a soundly engineered bike which looks correct for the period and I'd doubt if you'll have any problems.

I'd love to know what weird set of circumstances got you a CBR motor and an FZR frame....

[codgyoleracer]

Chapter 25 on the MNZ website. Have a really good read, it should explain most things.

Yip i agree, rules on wheels are quite clear.

[codgyoleracer]

So interpretation. If you kept the componentry true to the frame, and only changed the engine (even to a different breed), that would be okay?
Does anyone know if there is a section in rules dealing specifically with engine swapping?
ps Well done in the weekend Glen

Yeah, had a great time at Paeroa. Download the rules at MNZ or NZPCRA, they ate overall pretty brief aye.
Good to hear of another postie on the way !
GW

[codgyoleracer]

In the pre 89 period, F3 and F2 were pretty much open GP style classes. Stay under the engine capacity rules and you were OK.

i saw a number of specials using the Kawa 500 motor in various frames, singles were put into a wide variety of chassis.
One thing which will get attention is making your CBR a 450...up to F2 you go sir...Unless it's already a 600 CBR ? In which case I know of a 600/400 frame hybrid done in period in NZ.

There is no specific set of rules relating to engine swaps - read Motorcycles Technical in the MNZ rules, build a soundly engineered bike which looks correct for the period and I'd doubt if you'll have any problems.

I'd love to know what weird set of circumstances got you a CBR motor and an FZR frame....

Dont get me startted on the 450's must be in F2 rule............, one of the dafter ones that......

[worm13]

Dont get me startted on the 450's must be in F2 rule............, one of the dafter ones that......

Dont you get me started mr Williams!! hahaha where alse they gonna go? the rules have been based around that period.... yes there were a few people running 450s in f3 but that wasnt written in the rule book so call it what ya want. I asked the question if I could change my frame to a frame style what you run with your SV, if you look back that sorta thing was done in the day but not with a zxr and even if I keep the geo to the same spec etc etc it still cant be done so for the weight saving thing no more pies for me but was worth asking about.

[malcy25]

I asked the question if I could change my frame to a frame style what you run with your SV, if you look back that sorta thing was done in the day but not with a zxr and even if I keep the geo to the same spec etc etc it still cant be done

Chapter 25 covers this. Frames (along with swing arms, major engine castings, carbs, forks, brakes) are a major component and the the items which date the bike. Essentially these bits must be from the period, or a prior period. This means no making a frame of any design to carry an old motor. If you do manufacturer or have created from scratch any of the major components, they have to be replicas of what was available within the period and proof that it existed in the period is with the rider. The age of the most modern major component determines what age group you run in. Eg 1982 GSX1100 with 1986 GSXR1100 forks is a pre 89 bike.

When the rules say replica, this means exact copy replica, not just of the same technology. This means that if you wanted to use a tube frame replacing an alloy one, and you are going to make it, you have to copy one that had been done within the period and not just one you made to a desiogn you thought up last week.

Another example of how people misinterpret the rules is if you want to fit 4 pot Brembos on your pre 89 bike, That's cool. It just can't be ANY four pot Brembo, but one that was available before Dec 31st 1989.

HTH

[worm13]

I knew I was pushing my luck, looking a Kevin's mac the idea poped into my head.. very little thought process went into... in fact the only thought was.... that would be cool. Rules a clear imo you only question how its worded if your trying to push the boundries, I got a little upset after weighing my bike at 159kgs I was hoping a whole heap less, on paper at the moe im at 152kgs