Nissan QR engine

The QR family of inline-four piston engines by Nissan were introduced in 2000 and range from 2.0 to 2.5 L (1,998 to 2,488 cc) in displacement. These motors are aluminum, dual overhead camshaft (DOHC), four-valve designs with variable valve timing and optional direct injection. The engine shares much of its architecture with the YD diesel engine.

Nissan QR engine
A Nissan QR25DE Engine
Overview
ManufacturerNissan (Nissan Machinery)
Production2000–present
Layout
ConfigurationInline-four
Displacement2.0–2.5 L (1,998–2,488 cc)
Cylinder bore89 mm (3.5 in)
Piston stroke80.3 mm (3.16 in)
100 mm (3.94 in)
Cylinder block materialAluminum
Cylinder head materialAluminum
ValvetrainDOHC 4 valves x cyl. with VVT
Compression ratio9.1:1-10.5:1
Combustion
SuperchargerOn QR25DER only
Fuel systemPort Fuel Injection or Direct Fuel Injection
Fuel typeGasoline
Cooling systemWater-cooled
Output
Power output103–186 kW (140–253 PS; 138–250 hp)
Torque output200–330 N⋅m (148–243 lb⋅ft)
Chronology
PredecessorNissan SR engine
Nissan KA engine

QR20DE
QR20DE

The 2.0 L (1,998 cc) QR20DE produces 140 PS (103 kW; 138 hp) at 6000 rpm and 200 N⋅m (148 lb⋅ft) at 4000 rpm. The bore and stroke is 89 mm × 80.3 mm (3.50 in × 3.16 in) and a compression ratio of 9.9:1.[1] The QR20DE was replaced with the MR20DE engine in most applications in early 2005.

Vehicle applications:

QR20DD

The QR20DD is similar to the QR20DE but features NEO direct injection to improve fuel economy and to reduce emissions. It produces 150 PS (110 kW; 148 hp) at 6000 rpm and 200 N⋅m (148 lb⋅ft) at 4400 rpm.[1]

Vehicle applications:

QR25DE
Nissan QR25DE Engine

The QR25DE is a 2.5 L (2,488 cc) variant built with cast steel connecting rods, a steel timing chain, counter-rotating balance shafts, and an aluminum intake manifold. The engine bore and stroke is 89 mm × 100 mm (3.50 in × 3.94 in) and a compression ratio ranging from 9.5:1 to 10.5:1 depending on the vehicle.[2]

Output is rated 175 hp (130 kW; 177 PS) at 6000 rpm with 244 N⋅m (180 lb⋅ft) of torque at 4000 rpm in the Altima 2.5 and Sentra SE-R models. Altimas that are PZEV compliant create 170 hp (127 kW; 172 PS) and 175 lb⋅ft (237 N⋅m) of torque. In the 2005+ Nissan Frontier the QR25DE generates 152 hp (113 kW; 154 PS) and 171 lb⋅ft (232 N⋅m) of torque.

2007+ QR25DE

The revised QR25DE found in the 2007+ Sentra, Altima, Rogue, etc. has a number of improvements over the older QR25DE. These include:

  • A simpler, larger diameter single path resin intake manifold replaced the old dual path design. (Note: California emissions models do have a swirl control valve located in the intake)
  • Revised piston crown shape to support a higher compression ratio of 9.6:1.(10.5:1 in Sentra SE-R Spec V.)
  • The balancer system has been moved back slightly from the crank pulley to a more centric location in the block.
  • Revised cam shaft profile.
  • Reinforced connecting rods only available in the Sentra SE-R Spec V 2007-2012 .
  • Reduced friction likely through Nissan's extensive use of coatings on pistons, journal bearings, etc.
  • Additional engine mount on the top of the motor, pulley side.
  • Higher rev limit and improved power output.
Vehicle applications:


QR25DD

The QR25DD is similar to the QR25DE but increases the compression ratio to 10.5:1 and includes direct injection. This engine is also the first QR to use DLC coating on the valve lifter buckets for reduced friction. It produces 125 kW (170 PS; 168 hp) at 5600 rpm and 245 N⋅m (181 lb⋅ft) at 4000 rpm.[1]

Vehicle applications:

QR25DER

The QR25DER is similar to the QR25DE but has a supercharger for increased power and is coupled with a 15 kW (20 hp) electric motor, Dual Clutch System, and lithium-ion battery for increased fuel efficiency. The engine has a compression ratio of 9.1:1 (10.0:1 in 2014 Infiniti QX70, others may be similar) and produces a combined 250 hp (186 kW; 253 PS) at 5600 rpm and 243 lb⋅ft (329 N⋅m) at 3600 rpm.[3]

Vehicle applications:

See also

References
  1. Yamaguchi, Jack. "Two midsize Nissans for Japan and Europe". SAE International. Archived from the original on 2004-06-25.
  2. nissannews.com
  3. "Nissan Online Newsroom". Archived from the original on 2014-04-26.

General references
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