NC35 and NC30 head interchangeability?

scooble · Post by **scooble** » Sun Oct 16, 2011 2:47 pm

Does someone know if a complete cylinder head for an NC35 will bolt straight onto an NC30 and vice versa without any mods

Post by **skinnydog0_0** » Sun Oct 16, 2011 4:09 pm

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.

Post by **CMSMJ1** » Sun Oct 16, 2011 7:59 pm

As Jeff syas - straight swap

Dionysus · Post by **Dionysus** » Wed Oct 19, 2011 7:30 am

What difference will this make?

Post by **skinnydog0_0** » Wed Oct 19, 2011 12:08 pm

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.

Post by **Neosophist** » Wed Oct 19, 2011 1:25 pm

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?

Dionysus · Post by **Dionysus** » Wed Oct 19, 2011 1:51 pm

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

Dionysus · Post by **Dionysus** » Wed Oct 19, 2011 1:53 pm

NC30 - 32mm Circular-Piston, 20mm Intake Valve
NC35 - 30mm T-Piston , 19mm Intake Valve

Dionysus · Post by **Dionysus** » Wed Oct 19, 2011 2:15 pm

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.

scooble · Post by **scooble** » Wed Oct 19, 2011 4:07 pm

so, as the NC35 has 1mm smaller inlet valve, is there any advantage of retaining the NC30 valves but using the NC35 calms?

NC35 and NC30 head interchangeability?

NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?

Re: NC35 and NC30 head interchangeability?