Revision as of 09:51, 31 December 2014

The Datsun 1200 came only the Nissan A12 engine, a nominally 1200 cc engine that matches its name. It is actually 1171 cc. The A12 debuted in 1970 in the first Datsun 1200, and is a redesign of the earlier A10 engine used in the Datsun 1000. It is a traditional type inline 4 cylinder, with overhead valve cylinder head. The A12 engine is a superb little economy engine with good performance and legendary reliability. The Datsun 1200 GX trim model came with a Twin Carburetor A12GX Engine.

1 Overview
2 Specifications
3 Applications
- 3.1 A12 Twin-Carb Engine
- 3.2 A12 Works Engines
4 Stroker Motors
- 4.1 A14 crank
- 4.2 A15 crank
5 Photo Index

Overview

See Nissan A Engine for a more general overview about this engine family.

A12 Engine

A12 GX Engine

A12 Engine ID Mark

Specifications

Specifications:

Bore: 73mm
Stroke: 70mm
Connecting rod: 121.5mm
Block Height: 189.1mm
Displacement: 1171cc
Compression ratio: 9.0:1 or 9.5:1
Power: 68hp or 69hp (depending on year and country)

The A12 is a 1171cc engine with 73mm bore, like the previous A10 engine, but the stroke is increased to 70mm. With upgraded five main bearings on a forged steel crankshaft, the A12 is extremely smooth and durable. The 2-barrel Hitachi carburetor was significantly improved with the addition of a power valve circuit. It produced 69hp (51.4kW) and 70 lb.f.t torque (94.9Nm).

Applications

1971-1973 Datsun Sunny 1200 B110
1971-1973 Datsun 1200 pickup B120
1971-1973 Datsun Cherry E10 (Datsun 120A)
1980s Premier NE118
Sado truck

A12 Twin-Carb Engine

A special version of the A12 was the twin-carburetor version, which Nissan called the A12 GX in the Datsun 1200 and A12T in the Datsun Cherry. With twin Hitachi sidedraft carburetors, a longer duration camshaft and 10:1 compression ratio, the engine provided 83hp @ 6400rpm, up 20% from the standard A12 engine. The GX engine was offered in Japanese Domestic Market Datsun 1200 GX sedans and coupes. The identical specification A12T engine was offered in the front-wheel-drive Datsun Cherry X-1R Coupe.

A12 GX engine

Late-model A12T (1974 type)

A12 Works Engines

Works (factory sponsored) racing cars used an overbored 1300cc A12, or the special hemi-head AY12 engine.

1300cc A12

An overbored version of the A12 was used in period race cars, including Nissan factory 'works' racing Datsun 1200s. Many A12s were bored from the original 73 mm to 76.76 mm and fitted with Tomei forged pistons for a displacement of 1296 cc while others used the Datsun Competition forged pistons of 76 mm to displace 1270cc. These legendary engines competed in Japan's Touring Sedan (TS) class races against the 1200's archrival Toyota Starlet.

See Racing History

AY12 Engine

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.

AY12 was used in under-1300cc class racing with 76 to 76.8mm pistons. Intake valve was 40-41mm and exhaust valves that have been used are 33mm and 34mm. The piston was also special design. Because of the hemi combustion chamber, the pushrod-activated valve rocker system was different from the regular A12.