1981 Engine

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[[Category:Engine Mechanical]

To comply with 1981 emission standards, improve fuel economy and increase driveability, the A-series engines for USA and Canada have undergone several modifications.

Datsun 210

An A15 engine has replace the A14 engine model formerly used with the manual transmission. The A14 engine has also replaced the A15 engine in MPG models, providing a new addition to the current selection of models available for non-California and Canada destinations.

Datsun 310

An A15 engine has also replaced the A14 engine formerly used in the N10 Pulsar front wheel drive chassis.

Engine Mechanical System

To meet emission control standards and to improve combustion properties, the following modifications have been made:

* In order to increase the "skish" effect, the combustion chamber design has been modified and the lower surface area of the combustion chamber has been reduced. In conjunction with these change the valve seat has been installed in a slightly higher position. 

• The spark plug has been moved 6 mm (0.24 in) closer to the center of the combustion chamber for increased ignition performance.
• Weirs have been added inside the intake port to increase the "swirl" effect. Additionally, the cross-sectional area of the port has been increased in relation to the reduction of the intake valve diameter at the bevel.

Valve

To accomodate the new combustion chamber design, the intake and exhaust valves have been shortened by 4 mm (0.16 in) and the diameter of the intake valve at the bevel portion reduce from 37 mm dia. to 35 mm dia.

• 1981 length: 100 mm
• 1980 length: 104 mm

• Exhaust valve head: 30 mm
• Intake valve head 1980: 37 mm
• Intake valve head 1981: 35 mm

Piston

The crest of the piston has been redesigned to accomodate the new combustion chamber design. The piston ring groove has also been modified to match the new top ring design.

The specifications for the piston rings used in the A14 and A15 engines have been revised for lower oil consumption.

Top Ring:

• 1980 : Barrel type face 1.2 mm steel
• 1981 A14: Taper type face 2.0 mm cast iron
• 1981 A15: Taper type face 1.2 mm steel

2nd Ring:

• 1980: Taper type 2.0 mm cast iron
• 1981: Under-cut type 2.0 mm cast iron