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NC35 and NC30 head interchangeability?

Posted: Sun Oct 16, 2011 2:47 pm
by scooble
Does someone know if a complete cylinder head for an NC35 will bolt straight onto an NC30 and vice versa without any mods

Re: NC35 and NC30 head interchangeability?

Posted: Sun Oct 16, 2011 4:09 pm
by skinnydog0_0
Yes, i have a set of 35 heads and cams on my uk spec 30 engine, and i cant remember having to do any mods for that.

Re: NC35 and NC30 head interchangeability?

Posted: Sun Oct 16, 2011 7:59 pm
by CMSMJ1
As Jeff syas - straight swap

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 7:30 am
by Dionysus
What difference will this make?

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 12:08 pm
by skinnydog0_0
35 cams have a different lift/duration over the 30 cams. The 35 cams are better. As far as i know the heads are the same possibly lighter on the 35.

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 1:25 pm
by Neosophist
skinnydog0_0 wrote:35 cams have a different lift/duration over the 30 cams. The 35 cams are better. As far as i know the heads are the same possibly lighter on the 35.
Doesn't the 35 have 1mm smaller valves?

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 1:51 pm
by Dionysus
Neosophist wrote:
skinnydog0_0 wrote:35 cams have a different lift/duration over the 30 cams. The 35 cams are better. As far as i know the heads are the same possibly lighter on the 35.
Doesn't the 35 have 1mm smaller valves?
Apparently so :|

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 1:53 pm
by Dionysus
NC30 - 32mm Circular-Piston, 20mm Intake Valve
NC35 - 30mm T-Piston , 19mm Intake Valve

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 2:15 pm
by Dionysus
A good deal of the weight saved in the engine comes from the use of hollow camshafts. This also helps to reduce inertia. The NC35 exhaust cam is a slightly steeper profile; 1mm lift is achieved at 142-degrees, as opposed to 145-degrees on the NC30 cam (measured from 0-degrees cam angle). This will help speed up venting of the cylinder, effectively giving more opportunity for the rising piston to push out the exhaust gases. Total lift and duration are identical between engines.

The NC35’s inlet cam has a slightly longer duration; the extra 3-degrees are gained before effective opening, suggesting the cam initially opens the valve less aggressively, whilst still achieving the same total lift of 7.7mm.

Re: NC35 and NC30 head interchangeability?

Posted: Wed Oct 19, 2011 4:07 pm
by scooble
so, as the NC35 has 1mm smaller inlet valve, is there any advantage of retaining the NC30 valves but using the NC35 calms?