NC30 vs NC35 engine differences

[VFRkieran]

Unless im mistaken and alot of the time i am, the NC35 engine is in total 1kg lighter than the 30, its a combination of lighter clutch, cams, genny and i think the heads are lighter too. Different pickups narrower inlet ports and different gearbox. I think the Pistons have a shorter skirt and are roughly 0.1g lighter, all that adds up to quite alot, just fitting 35 cams to mine made a nice difference!

Also your a git sniped that engine off me by 2 seconds lol, that would have been some nice spares for my race bike.

[Bike_Nut]

Sorry, but it was too good to give up!

As for the lighter genny, is it just the windings or the flywheel part that is lighter? If nobody knows for sure I will try measure them back to back at some point

[Drunkn Munky]

Unless im mistaken and alot of the time i am, the NC35 engine is in total 1kg lighter than the 30, its a combination of lighter clutch, cams, genny and i think the heads are lighter too. Different pickups narrower inlet ports and different gearbox. I think the Pistons have a shorter skirt and are roughly 0.1g lighter, all that adds up to quite alot

Ths is why im bemused as to why so many people break complete rvf motors to pillage parts for their nc30's, surely it makes more sense to just fit an rvf motor no? I mean its fair game if the motor is scrap but ive seen so many good engines over the years ruined because of this, I shudder to think how many rvf's out there are unknowingly running vfr cams now.

[VFRkieran]

Yea it amazes me too I think the main reason why the RVF only puts out 53bhp is down to the carbs, I spoke to a few guys racing nc's at the Manx and a lot of them where using RVF engines with either open VFR carbs or ramair so if you ask me the RVF engine is the better of the 2 but it's just harder to get the power.

Just my humble opinion after looking into it a little bit.

[Drunkn Munky]

The engine has nothing to do with the 53bhp thats in the restrictive RVF end can and possibly the carbs, the RVF engine is better and the better of the 2 for getting power from. I think it was RLR i spoke to many years ago about building me a motor and he point blank said he wouldn't entertain using a VFR motor and if i wanted them to do the build then to supply a RVF one. Even the stock RVF system is good for power once the can is binned.

[VFRkieran]

Oh yea i definatly agree with that, the RVF motor is much stronger for sure. From my experience comparing my NC30 and a friends 35 very similarly setup, both had jetted and setup carbs, chopped system on mine with beowulf end can and a chavvy pipe worx can on the RVF.

If we where alongside at low speed, he could get away slightly as we accelerated but as soon as we got up to higher speeds my NC30 would get ahead and keep pulling away until we hit about 125-135mph and we would just sit at the same distance.

So IMO its all in the carbs, what carbs where you running on your 35 at cadwell mate? From what i remember mine started to outdrag yours right at the end of the straights, both with full systems but i was running 35 cams.

[Drunkn Munky]

Yep stock 35 carbs with 112 mains with +2 on the rear sprocket. in an ideal world you'd have the rvf carbs bored out but no one has yet shared the magic in doing it, either that or its too trcky to do. Im dont know what to current record holder uses (james will know) but a year or so ago the bike that held the highest speed record at the manx ran bored out rvf carbies.