Hi, just got a NC24 from my uncle who's had it sat in his garage for the last 12 years. He's recently been through it with a fine tooth comb so its sweet as a nut when it comes to running of the motor and system.
can anyone recommend any serious performance upgrade for these bike as I would like it to have a little bit more poke than it got now.
any idea would be great
Cheers

Only serious things you can do to a 24 are expensive engine work. maybe a bit to the carbs which wont get you much without a decent exhaust

The 24 doesnt seem to have many spare aftermarket parts, exhausts are like unicorn poo. A highly tuned engine with lots of money thrown at it will only get you tops of 70hp, so for the money to get that your better off buying another bike, there not a performance bike, there more of a handling bike.

All the best Rick

porndoguk wrote:Only serious things you can do to a 24 are expensive engine work. maybe a bit to the carbs which wont get you much without a decent exhaust

The 24 doesnt seem to have many spare aftermarket parts, exhausts are like unicorn poo. A highly tuned engine with lots of money thrown at it will only get you tops of 70hp, so for the money to get that your better off buying another bike, there not a performance bike, there more of a handling bike.

All the best Rick

I know where there is an HRC exhaust and HRC gearbox for one for sale

Yakama wrote:

porndoguk wrote:Only serious things you can do to a 24 are expensive engine work. maybe a bit to the carbs which wont get you much without a decent exhaust

The 24 doesnt seem to have many spare aftermarket parts, exhausts are like unicorn poo. A highly tuned engine with lots of money thrown at it will only get you tops of 70hp, so for the money to get that your better off buying another bike, there not a performance bike, there more of a handling bike.

All the best Rick

I know where there is an HRC exhaust and HRC gearbox for one for sale

wow, unicorn poo really is rare but not when liam is about :D

The HRC NC24 made 74ps, the HRC NC30 made 78PS.

Stock they both make around 60ps.

There isn't really any more performance to be had without throwing lots of money at the bikes.

The HRC versions were proper track bikes and as such would be rubbish on the road, 3000rpm idle, huge jets geared and fuelled for top end throttle.

I'd recommend an early cbr600 steel frame if you want more poke and fun to ride.

@ Neo, how different are the engine internals between the NC24 and the NC30?

Yakama wrote:@ Neo, how different are the engine internals between the NC24 and the NC30?

Wanting to do some hybrids? I've read and heard rumours many Japanese racers in the 400 classes who don't have the money to use a full HRC spec TT-F3 30 engine would use an NC24 engine as it's easier to maintain and had oil-cooler as stock and valve clearances are adjusted with locknut and screwdriver so no shims to buy, plugs are 10mm not 8mm so more choice available cheaper.

There both NC13E based engines so the outer-cases and ancillaries are pretty much the same.

They both use the same water-pump and sump / sumpgasket / clutch gasket / clutch case / thermostat housing although the sprocket cover is different as the NC30 gets is speedo reading from the front sprocket.

NOTE!

This is based on the NC24, many of the NC21 bits are older and different, even though the NC24 was only made for two years, many things evolved.. such as parts being superceeded by a revised part. Later NC24's will have this parts, eariler ones will have the older design. They should be interchangable but I presume the newer revision is more desireable else Honda would not have changed it.

Internally.

UK NC30 uses the same oil pump as the NC24 as it feeds the oil-cooler rad too.
Conrods are the same as are the con-rod bearing shells.

Pistons were changed (probably due to NC30 using larger valves / smaller spark plug.

Generator is the same, fly-wheel is different but can be retrofitted. (perhaps the 30 is lighter? the 30 had two different flywheels also, K models was Hitatchi, later was Nippon Denso

Clutch basket is the same but the internals are different, NC24 uses a non-slipping traditional coil-spring type clutch, since the basket is the same, with the clutch-rod and cover from the 24 you could fit this I believe.

Pickups are different as it has 4 sparkplugs.

Crankshaft is different shape as it fires 180 degrees.

The gearbox is different, shafts as well as gears and selector forks are all different. Ratios are different too, final drive on the 24 is 15/45 where as 15/40 on the 30 I think.


Top end is completely different, the only things the same are the valve-stem seals, valve guides and carb rubbers. The NC30 switched to shims instead of adjustable tappets. The plugs are smaller 8mm insted of 10mm and I belive the valves were made bigger (hence the smaller plug)

Camshafts / camcaps / camgears are all NC30 specific. Actual cylinder head is different too due to I think valve size (holes will be bigger).. cam profile is different (firing order is different so of course cams are differnet, but taking that into account, is still different)

Not sure if you could fit a complete 24 head to a 30 and use the NC30 camshafts, maybe. Parts are different but perhaps.

Bore / Stroke / Comp Ratio and power were the same between 24 and 30.

I suspect the piston change was for the valves only.

NC24:
55 x 42 bore/st
11.3:1 comp
59ps / 4.0 kg/m torque. [ 12,500 & 10,000 rpm]

Gears:

3.307
2.352
1.850
1.545
1.333
1.227 (NC21 was different 1.192)

PR / FD: 2.114 / 3.000

NC30:

2.928
2.166
1.800
1.591
1.435
1.318

fd / PR: 2.666 / 2.117

If you need any specific info let me know.

Neosophist wrote: If you need any specific info let me know.

Erm i think that was pretty comprehensive.
Also the 24 has thicker liners and is capable of being bored out further assuming you can get pistons made.

on the ball there neo as always :)

So could the barrels from a 24 be fitted to a 30 and still use the 30 heads?

barrels are part of the engine crankcases so i assume you mean use 30 heads on a 24 engine ? not sure i would doubt it