The Nissan A series of internal combustion gasoline engines have been used in Datsun, Nissan and Premier brand vehicles. Displacements of this four-stroke engine family ranged from 1.0-liter to 1.5-liter and have been produced from 1967 till 2009. It is a small-displacement four-cylinder straight engine. It uses a lightweight cast iron block and an aluminum cylinder head, with overhead valves actuated by pushrods.
The Nissan A engine design is a refined, quiet and durable gasoline engine. It appears to be a modern replacement of the earlier iron-headed Nissan C and Nissan E engines and is of similar dimensions. The 1960s E series was an all-new design from newly acquired Aichi Kokuki, and integrated Nissan's improvements to the BMC B-Series engine design of the 1950s (Nissan was a licensee of Austin Motor Company technology), mainly comprising changing the camshaft from the left side to the right side so removing the intrusion of the pushrods from the porting allowing 8 individual ports instead of 5 originally, and moving the oil pump from the rear of the camshaft to the right side of the block. As production continued, 1974 and newer A-series engines had different block castings, with relocated motor mount bosses.
A10: the first A-series engine
The A10 is a 1.0-liter (988 cc) engine, released in September 1966 in the 1967 model year Datsun 1000. The A10 featured a three main bearing crankshaft. Bore was 73 mm and stroke was 59 mm (same as the Nissan C engine). With a two-barrel Hitachi carburetor and an 8.5 to 1 compression ratio this engine produced at 6000 rpm and . The Datsun 1000 Coupé, introduced in Sept 1968, was equipped with an uprated A10 engine boasting a free flowing dual outlet exhaust manifold with increased compression, now 9 to 1. With a revised carburetor, this engine produced . Export versions of the A10 as installed in the Datsun 100A produced SAE at 6000 rpm and at 4000 rpm.
A belt-driven SOHC version of the A10 was built as the E10 into the early nineties.
Applications
1967–1970 Nissan Sunny (B10, B20; Datsun 1000) 1971–1976 Nissan Cherry (E10; Datsun 100A) 1974–1978 Nissan Cherry F-II (F10) 1978–1981 Nissan Pulsar/Cherry (N10)
A12 (1200): further refinements
The A12 is a engine with a bore, like the previous A10 engine, but with its stroke increased to . With five main bearings on a forged steel crankshaft, the engine is extremely smooth and durable. The two-barrel (twin-choke) Hitachi carburettor was significantly improved with the addition of a power valve circuit. The A12 engine produced and torque.
A special version of the A12 called the "A12 GX" engine, was available (A12GX or A12T for front-wheel drive applications). With twin Hitachi sidedraft carburetors, a longer duration camshaft and 10:1 compression ratio, it delivered at 6400 rpm, up 20 percent from a standard A12 engine. The GX engine was offered in Japanese Domestic Market Nissan Sunny 1200 GX sedans and coupes. The identical specification A12T engine was offered in the front-wheel-drive Nissan Cherry X-1.
An overbored version of the A12 was used in period race cars, including Nissan factory (works) racing Sunnys. Many were overbored from the original to using Tomei forged pistons for a displacement of , while others used Datsun Competition forged pistons, for a displacement of . These legendary engines competed in Japan's Touring Sedan (TS) class races against the 1200s archrival Toyota Starlet.
Perhaps the most interesting variety of A series engines was the AY12 engine. This was a special race-only Nissan factory (works) racing version with a crossflow cylinder head.
The AY12 was used in an under -class with a bore diameter. The intake valve was and exhaust valves were . The pistons were also a special design and the valve rocker system was different from the standard A12 due to the use of a crossflow layout for the racing engine.
Applications
1970–1973 Nissan Sunny B110, and B120 (Nissan Sunny Truck) 1971–1973 Nissan Cherry E10 (Datsun 120A) 1970 Nissan 270X concept 1985-2001 Premier 118NE (Fiat 124)
1974 redesign
For the 1974 model year, the A engine was modified, and all subsequent A engines use the new block style. Since there was increasing need for accessories like air conditioning, anti-pollution air pumps and the like, the distributor was moved from the front side of the engine to the middle of the block to make room for these accessories. Additionally, the motor mount positions were moved slightly. Nissan introduced its emission control technology, called NAPS (Nissan NAPS) with the redesign.
This "new" A12 retained the same bore, stroke and most other specifications of the previous A12.