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Will an NC35 engine fit into an NC30?

Posted: Wed Feb 03, 2016 10:32 pm
by racingt
Hi guys,
I have a spare 35 engine, carbs, coils, exhaust and was wondering if it would fit into a nc30?
Seen several high mileage 30s, would be tempted to buy if I knew I could do this swap.
Guessing, the electrics will be the main problem area?
Apologies, I'm sure this topic has been well covered before, but I cannot find the thread.
Cheers!

Re: Will an NC35 engine fit into an NC30?

Posted: Thu Feb 04, 2016 8:31 am
by Drunkn Munky
yes it fits, your need the starter clutch and pulse coils from the 30 engine unless you intend on swapping the RVF electrics, cdi etc over too

Re: Will an NC35 engine fit into an NC30?

Posted: Thu Feb 04, 2016 8:30 pm
by racingt
Thanks Drunkn. I'll look out for a worn out 30 now.

Re: Will an NC35 engine fit into an NC30?

Posted: Fri Feb 05, 2016 8:34 am
by Drunkn Munky
To be fair these motors are pretty tough and seem to last the life of the bike anyway, plus everyone charges a premium for RVF motors due to the slight internal changes and there getting rare due to people ripping them apart to fit the upgraded bits in a 30 motor to gain 0.0000001 bhp and lose 0.1 kg's. Due to this your be best to check any RVF motor you do intend on buying to see if its had its goodies swapped out for VFR parts, ive bought 2 like this so there out there.
You do get a stronger gearbox in a RVF though so if your planning on big power it would be the best option.

Re: Will an NC35 engine fit into an NC30?

Posted: Fri Feb 05, 2016 7:09 pm
by racingt
Thanks Drunkn, actually I have the NC35 engine and carbs already, came off a crash damaged, learner restricted bike, with 36,000 km on. Bought as a spare for my first 35. Looks completely original but haven't fired it up yet. Hence on lookout for bike with blown motor or similar. Happy to look for as long as it takes!

Re: Will an NC35 engine fit into an NC30?

Posted: Mon Feb 08, 2016 1:25 pm
by Neosophist
racingt wrote:Hi guys,
I have a spare 35 engine, carbs, coils, exhaust and was wondering if it would fit into a nc30?
Seen several high mileage 30s, would be tempted to buy if I knew I could do this swap.
Guessing, the electrics will be the main problem area?
Apologies, I'm sure this topic has been well covered before, but I cannot find the thread.
Cheers!
stock nc35 engine is going to be 6hp down on an nc30 engine too as they changed the hp limitation between after 93 so all 59hp bikes became 53hp.

Re: Will an NC35 engine fit into an NC30?

Posted: Mon Feb 08, 2016 2:03 pm
by Drunkn Munky
Isnt that restriction of power dealt with by means of jetting and exhaust though?

Re: Will an NC35 engine fit into an NC30?

Posted: Mon Feb 08, 2016 4:44 pm
by Neosophist
Drunkn Munky wrote:Isnt that restriction of power dealt with by means of jetting and exhaust though?
Not sure how its done on the NC35 / NC30 difference.. I know the NC35 is geared more towards being smooth on the road and around town.

The valves are 1mm bigger and the carbs are smaller too to aid in higher airflow through the engine.

I think with NC30 carbs and a free exhaust they do make around 60hp same as the 30 so you are probably right, don't think there is any restriction with the camshafts and what not.

Seen a few high hp nc35s so must be possible to tune some power out of them.

Soem other JDM bikes reduce hp by means of camshafts so probably not the case with this enigne, but if you bolt a complete stock kit onto an nc30 frame without any fettling probably be down on power.

Re: Will an NC35 engine fit into an NC30?

Posted: Tue Feb 09, 2016 3:19 pm
by fourfingers
The valves are 1mm bigger and the carbs are smaller too to aid in higher airflow through the engine.
Carbs are ideed different, 30mm ID nc35 vs 32mm ID nc30, but intake valves and valve seats are the same, and checking both heads I just see some difference in the intake head casting(19mm nc35 vs 20mm nc30). Anyway, a dremmel will easily fix this ;)

Also the gearshaft on the nc35 will offset the sprocket a couple mm left.

Re: Will an NC35 engine fit into an NC30?

Posted: Tue Feb 09, 2016 3:25 pm
by Neosophist
aha indeed

http://www.honda.co.jp/factbook/motor/R ... 0/004.html

plenty of info in the factbook there.

just checked and yep ports are 1mm bigger on intake on nc35 :)

it says the camshaft timing is a little different (picture of cams there too in above link) and due to this and the carb differences (straight intakes) they changed the port and fine sand casted / finishes the ports to improve airflow into the engine.