power for pound......one for the nc30/35 racers

[chrisxr]

nice one rhory glad your happy but.................. you need to adjust them cans so they run parallel and you have the snorkel on the ram air at the fairing upside down.........................The higher end on the cut back goes at the top spose it dont realy matter to much.

[Smev]

Just wondering about the big bore piston kits - how reliable would the engine be after? Will it need frequent re-builds or just the normal looking after (oil/Filter)?
One company used to do them - to take it to 444cc think it might have been Big CC Racing - anyone ever have one of these engines?
Do you do the big bore kits yourself Chrisxr?

[royster81]

nice one rhory glad your happy but.................. you need to adjust them cans so they run parallel and you have the snorkel on the ram air at the fairing upside down.........................The higher end on the cut back goes at the top spose it dont realy matter to much.

ol i was just saying to gareth i forgot to add at the bottom there are still a few teethin problems ,like you had mentioned lol but yes i am happy

looks fantastic (if not slightly like a letter box, especially being red) have you jetted it to suit now, i thought you were the guy with a hrc set up? or have you got both on different bikes?

ya cheeky wee blurt,post box indeed...lol..but yes i have the HRC set up on the bike at the minute,having a few problems to be honest,i used a set up that was given to me but the bike didn't like it,suppose it's not going to work with ever bike but i was hoping for the best,tomorrow i have a set of standard carbs and an FI jet kit going in,i'm going to stick with what i know if i'm going to get out anytime soon,and out is what i really would like to do

but while i'm at it i'll get a few pictures of it with it's clothes off and again with it's clothes on and a quick spec list,and i'll spend some time getting those cans straight lol

[chrisxr]

Just wondering about the big bore piston kits - how reliable would the engine be after? Will it need frequent re-builds or just the normal looking after (oil/Filter)?
One company used to do them - to take it to 444cc think it might have been Big CC Racing - anyone ever have one of these engines?
Do you do the big bore kits yourself Chrisxr?

problems with 444 kit is it passes due to design limits, no ones fault but its imposible to have the rings correct due to its size and availability of 58mm rings.

the 433 kit available is a safe option again offering about a 15 to 20% power gain these are well proved kits and used many times over. I do extra machining for these to reduce weight and get them close to original spec weight which makes these reliable. My best advice is to fit the kit rods rods and stainless valve set for ultimate reliabilty then you will see a engine capable of many miles obviosly any gains in performance will reduce engine life plus it depends just how the engine is used, but a well balanced big bore set of pistons will last a good while ive heard of road engines with 5000 on them so who knows. The problem with the aftermarket pistons used is they are much more tappered and do tend to rock a little more in the bore valve clearence issues then come a problem unless machined correctly.

A good option is to actually cut the rev limit a little when using a big bore, it sounds like something you dont want but its fine to kill off 500 rpm at the top. These kits will give you around 6lb ft more tourque than and taller gearing can be used and it will pull it very well.

Ultimate set up for road if money wasnt a issue would be
433 kit £450+vat
stainless 1 pce valves £19ea + vat (16 required)
Kit Rods £900 +vat
programable ignition £200
New main and big end shells £8 each (roughly)
Rebore cost on V engine £150
Gaskets £120
cost for assembly, piston macining, balancing and tuning £350

That set up would guarentee you a very long life out of your motor and a bike that would be seriously good fun to ride with a genuine top speed capability to make your 400 very interesting.

other oversize options are available 480 i beleive with a stroked crank a 530 is capable but i am unaware of these parts and cost of linners would become a new factor. I am in the process of a 1mm setup which wont have a great power affect as the 2.5mm or 3mm option but what this does is allow you to have your cylinder rebored which on many engines i have seen of thes bikes 15 yr old + in age they desperatly need it power is definatly being lossed through barrel ovality and marks. Plus in the design of the piston extra compression can be acheived. If these can be made legal for club racing i will go ahead with these.

[CMSMJ1]

Just when I thought I could not spend any more money....

I want some of those link pipes..

Am getting my Yamamoto welded where it cracked and then will sell my Ethos to fund the cans and link pipes...

Looks great mate.

Good work Chris.

[royster81]

i forgot to say to you mark ,chris can get stuff tig welded so it might be just as easy to send the lot to him to sort out

has anyone got one of the programmable cdi's and what did they think of them ?

to be honest i'm really thinking of one for the road bike as i believe they would be kick ass on the road

[viper_biker]

OK, so due to time and money constraints, I have taken over the ram-air side of things. I have encountered some issues but that was all down to me, nothing to do with the kit supplied.

Firstly, a big thank you to Chris who supplied the bits and has done the research into the set-up of this on 400's.

Tonight I finished fitting the kit to my bike and it's running perfectly fine. My bike is nothing more than an ex-road bike turned track bike. Motor is standard as is most other things. What I do have though is as follows,

Yamamoto single can 1/2 system (hope to go stack at some point)
HRC tap mod
YZF600 fuel pump
Dry break fuel coupling
Cleaned and balanced carbs
0.5mm washer under standard needles
3 turns out on the a/f screw
#135 mains and standard pilots
Carbs plumbed into the air box as instructed
Velocity stacks removed

I think that is it. The issues I ran into were all down to the fuel tap mod not being done correctly and the tap had shut off the fuel into the hoses, pump and carbs (plus I did kink one of the fuel hoses too) I have only had the bike out on a short stretch of private road that will only allow me to get to about 9,000rpm but up until there is was perfect. No hesitency or fluffyness, just quickly spun up.

Here are a few pics of some of the work as well as the finished article,

[hannakournikova]

a few empty bottles of magners in the background there too gareth in your utility room
good lad!

[viper_biker]

a few empty bottles of magners in the background there too gareth in your utility room
good lad!

[Spike16]

postman pat! , nah im just jokin it looks ggggrreeat