Nissan Anti-Pollution System (NAPS) was the market name for Nissan's collection of emission controls. Sometimes confused with the Nissan Z Engine, NAPS was used from late 1975 on many types of Nissan engines, including A14 engines. A catalytic converter was the heart of the NAPS system.
NAPS日産排出ガス清浄化システム -- Nissan NAPS exhaust gas cleaning system.
エンジン改良＋酸化触媒」- slogan "Improved engine + oxidation catalyst system"
Oct 27, 1975: B120 Datsun 1200 Pickup B120
- H-emissions (H-B120) 50年度排出ガス規制適合。
- 50th-year relevant regulations of emissions (Showa 50 = 1975).
- Nissan catalyzed oxidation of exhaust gas cleaning system "NAPS" adopted
NAPS emblem for Japan-market Datsun B210
Album click to view
マーク エンブレム NAPS
To meet 53-year (1978) emission standards, NAPS-Z was introduced. Fast burn combustion chamber with dual spark plugs to reduce noise. To improve power a turbocharged option engine was available (Z18T).
High fuel efficiency is realized by the adoption of a fast-burn combustion system, made possible by the development of a high-speed swirl system and twin-plug combustion chambers. Advanced EGR with a VVT valve obtains precise control. EGR distribution is improved by modification to the inlet manifold.
However, regular NAPS was modified to meet the 1978 emission standards, so the NAPS-Z was not entirely necessary. For example, VVT was adapted to the A-series engines with similar effect.
1982 Nissan Stanza (T11) -- the first Nissan-badged car sold in USA -- with trapezoidal-shaped combustion chambers for California models. In 1983 NAPS-X was fitted to all Stanzas. 46 mpg highway, 32 mpg city was very impressive.
NAPS-X CA20E 2.0 1974cc compared to NAPS-Z Z20E
- 77 pounds lighter
- More HP
- Better fuel economy
- 88 HP with dual plug version