How to build a NC30 race bike?

[Cal Walker]

Hi guys,

I brought a NC30 engine ages ago now with a suspected crank bearing failure, I got it for a bargain and couldn't refuse it! As winter is nearly here the plan is to strip and rebuild it. After a bit of thinking I've came to the conclusion that I'd love to build a track/race bike from it and buy a NC30 frame to house it in and build my way up from there.

I've got the general idea in my head, but is there any manuals or anything regarding specs and do's and don't's? Also if anybody has done this before and can give me some help and guidance on it, I would really appreciate that!

Many thanks.....Cal

[Neosophist]

Check the document library, the HRC NC30 TT-F3 manual is there.

The HRC spec was the race spec NC30.

Bascially your stock NC30 with a load of HRC parts and modifcations done to it to turn it into a track bike.

Power was up to just shy of 80hp but totally unusable for the street.

Most of the kit parts like cams pistons etc are long discontiniued and fetch a ton of money when they do come up but the manual does show how the port the cylinders and what not.

with a bit of cylinder head work and open hrc style carbs (Rick O does a great copy set) you can still have a decent track bike beast.

Maybe shy of the HRC spec power but a definate improvement over standard without spending litleralyl thousands of pounds to get HRC stuff.

Other opeion is overbore cylinders (again big bucks but pistons are out there).. if your not limited to 400cc class of racing

[Cal Walker]

Wicked! Cheers Neosophist.

Don't suppose there's a English translation of the HRC NC30 TT-F3 manual is there?

Sounds like I should focus on keeping the bottom end standard then. What type of modifications should I be looking at for the cylinder heads? Carbs look interesting! I'll defiantly give Rick a shout when I come round to it for the HRC replica stuff.

Any comments welcome!

Cheers....Cal

[Drunkn Munky]

In short remove anything you dont need and whatever is left make as light as possible, my RVF makes 67bhp on a stock motor with full HRC carbs although he dyno is possibly a bit optimistic pulls like a train though and hasn't affected the low down power

[skinnydog0_0]

if its just going to be for short track, get a good battery and run total loss. If you dont want to keep charging the battery between outings, get the GSXR genny conversion kit. I ran it on my last race bike and its very good. make sure you get an upgraded reg/rec as the Gixer genny pums out some serious power. I melted the reg/rec plug on my loom
Also first thing to spend on is suspension. Keep engine stock upgrade carbs and exhaust, but spend your cash on getting a good suspension set up.
I have run Maxton and Nitron on my last race bike and Both very good. I think i prefered the Maxton, but its really knit picking and down to personal preference.

[Yakama]

Wicked! Cheers Neosophist.

Don't suppose there's a English translation of the HRC NC30 TT-F3 manual is there?

Sounds like I should focus on keeping the bottom end standard then. What type of modifications should I be looking at for the cylinder heads? Carbs look interesting! I'll defiantly give Rick a shout when I come round to it for the HRC replica stuff.

Any comments welcome!

Cheers....Cal

I sell a translated copy of the f3 manual for £30 pm me if interested in one

[VFRkieran]

Spend shed loads of time and money building one and then have no time or money left over to actually do trackdays or racing, that's how I did it anyway

[Cal Walker]

Cheers Yakama, probably won't be this month mate, but I'll maybe give you a shout next month for one

Its gonna take me a bit of time VFRkieran, as funds wont quite let me go all in at once , but I'll have plenty of time to look at it when I do as I want to do a bit of a Guy Martin job on it and build it in the front room, that may take some persuading though!

[lukemillar]

Sounds like I should focus on keeping the bottom end standard then. What type of modifications should I be looking at for the cylinder heads? Carbs look interesting! I'll defiantly give Rick a shout when I come round to it for the HRC replica stuff.

Any comments welcome!

Cheers....Cal

From experience, I'd keep the bottom end standard as well. I'd be inclined to rebuild it with new bearings but that would be it. I spent a lot of time and money matching pistons, rods and crank balancing and the pay off was small so I wouldn't do that again.

For top end, head skimming was pretty successful but you'll need to get shims made up to restore the height between the crank and the cams. I have done some mild port clean up and inlet rubber matching but it is something I'd like to experiment more with. Problem is, you need a stack of spare heads and a flowbench to really quantify if what you are doing is better! Beyond that, different cam grinds and cam timing is also where I am at. Problem with all of this is the bang for buck is expensive compared to the cost of a different (more modern) bike with more cubes, so it really is engine building from the heart, not the head if a faster bike is the ultimate goal!

[Cal Walker]

Cheers Luke

I think I was actually looking at your project thread the other day.....the NC looks bloody awesome mate!

Cheers for the helpful information!

Regards....Cal