Honda R18 engine

The Honda R18 type engine (Honda Rgata engine) is an in-line 4-cylinder 1.8L gasoline engine for medium-sized vehicles manufactured by Honda Motor Co., Ltd. As of September 2019, only products for export to Japan are manufactured.

History

The 1,800cc R18A was adopted for the first time in the 8th generation Civic announced on September 28, 2005.This model was developed as a successor to the D17A and B20B, each with two intake and exhaust valves. The valves are opened and closed via rocker arms by timing chain driven camshafts. On the intake side, I-VTEC 's "variable intake air volume control" is adopted, and by switching between the Miller cycle and the Otto cycle, both high output and low fuel consumption are achieved. In the Miller cycle, one side of the intake valve closes late during low-load driving, and the air- fuel mixture that has been taken in is pushed back during the upward stroke of the piston. Delayed closing of the intake valve is realized by switching to a cam with a wider working angle than usual. In addition, the use of drive-by-wire reduces throttle throttling and reduces pumping loss.

The bore pitch of the cylinder block has been expanded from 84mm of the D type to 88mm, but the narrow cam chain and chain case with built-in oil pump have succeeded in making it compact and lightweight. The piston is cooled by an oil jet to increase the compression ratio. There is no exhaust manifold, and the distance between the engine and the three-way catalyst is brought closer, making it possible to purify the exhaust gas from an early stage even when it is cold, contributing to weight reduction and compactness.

R18A

• Valve mechanism: SOHC I-VTEC chain drive intake 2 exhaust 2
• Displacement: 1,799cc
• Inner Diameter x Stroke:  81 mm × 87.3 mm (3.19 in × 3.44 in)
• Compression ratio: 10.5:1
• Fuel supply device type: Electronically controlled fuel injection type (PGM-FI)
• Reference specs (RN6 stream)
• Maximum output: 140 PS /6,300rpm
• Maximum torque: 174 Nm (17.7 kgm) / 4,300 rpm
• Redline: 6800 rpm

R18Z

• Displacement: 1.8 L; 109.8 cu in (1,799 cc)
• SOHC iVTEC (Chain driven cam) Single valve mode at low RPMs
• Compression: 10.6:1 
• Bore & stroke: 81 mm × 87.3 mm (3.19 in × 3.44 in)
• Power: 145 PS (107 kW; 143 hp) at 6,500 rpm
• Torque: 17.8 kg⋅m (175 N⋅m; 129 lb⋅ft) at 4,300 rpm
• Redline: 6800

Installed vehicle 

• Honda  Stream (RN6/7)
• Honda City
• Honda Civic (FC6 FD1 FN1 FK2 FK5 FB2, FG3)
• Honda Crossroad (RT1/2)
• Honda FR-V (EDIX for Europe)
• Honda HR-V
• Honda Jade