N-VCT
Nissan Variable Timing control[1] or Nissan Valve Timing Control System (commonly known as N-VTC, VTC, NVCS or NVTCS) is an automobile variable valve timing technology developed by Nissan. N-VTC was first introduced in 1987 on the VG30DE and VG20DET engine.
N-VTC varies valve timing by rotating the affected camshaft(s) relative to the sprocket; valve lift and duration are not altered. This rotation is achieved when an electric solenoid, controlled by the car's ECU, allows pressurized engine oil to flow into and through the cam and into a slave mechanism, axially advancing camshaft timing relative to the sprocket. Valve to crank angle timing varies depending on whether engine speed is high or low and changes at fixed intervals. NVTCS is hydraulically actuated similar to Honda's VTEC system, but adjusts a different aspect of the valve train, so it is more like the I part of I-VTEC.[2][3] NVTCS equipped Nissan engines do not have as high of engine speeds as VTEC equipped engines so NVTCS is simpler, quieter, and requires no special maintenance. Some Nissan engines only have N-VTC on the intake cam such as the GA16DE,QG16/18, SR20DE/DET (S14-15) or RB25DE/DET (R33-R34 GTS/GTS-T, GT/GTT) while others have it on both the intake and exhaust cams. NVTCS was eventually phased out and replaced by a continuously variable system called CVTCS on newer engines such as the VQ and VK series.[4]
List of engines
See also
References
- S14 nissan workshop manual (PDF). pp. EM9, EC17.
- 可変動弁システム:日立オートモティブシステムズ株式会社日立オートモティブシステムズ製品紹介
- Schaeffler Japan | プレスオフィス | 可変バルブタイミング機構の電動化により環境性能を向上
- Z33の「35th Anniversary」モデル、およびマイナーチェンジ以降のモデル