Editing Quad 4 engine (section)

=== LD2 ===
[[File:Quad4-89Calais.jpg|thumb|right|280 px|A 2.3-liter Quad&nbsp;4 in 1989 Cutlass Calais]]
The LD2 is the original version of the Quad&nbsp;4, introduced in 1987 for the 1988 model year. Bore × stroke are {{cvt|92| × |85|mm|in|1}}, for a displacement of {{cvt|2260|cc|cuin|1}}. In base form it put out {{cvt|150|bhp|kW|0}} from 1988 to 1989 and {{cvt|160|bhp|kW|0}} from 1990 to 1992. The naturally aspirated Quad&nbsp;4 was able to produce that power with a 9.5:1 [[compression ratio]], and was able to meet [[emission standards]] without using an [[Exhaust gas recirculation|EGR]] system. 

Minor running changes to the base Quad&nbsp;4 included different crankshafts, cams, and [[manifold (automotive)|manifold]]s, all meant to increase torque and reduce NVH. 

A slightly augmented version of the LD2 was offered in some [[Oldsmobile Achieva]] models with the SC (and possibly SL) trim packages. In this application the LD2 engine had a device called a vortex valve installed in the throttle body, and a ram-air cold-air intake was installed near the driver's side headlamp with ducting to direct the air to the engine intake.<ref name="mcg-scc"/><ref name="bf-jul2022"/> While some references rate this engine at 180&nbsp;hp, Oldsmobile's own literature reports a number of {{cvt|170|hp|kW}}.<ref name="brochure-1994"/>

Applications:
* 1988–1991 [[Buick Skylark]]
* 1992–1994 [[Oldsmobile Achieva]]
* 1988–1991 [[Oldsmobile Cutlass Calais]]
* 1990–1991 [[Oldsmobile Cutlass Supreme]]
* 1988–1994 [[Pontiac Grand Am]]
* 1990–1991 [[Pontiac Grand Prix]]
* 1993–1997 [[Pontiac Trans Sport]] (Europe only)

==== 1995 ====
[[File:Quad4-95Z24.jpg|thumb|right|240 px|A 2.3-liter Quad&nbsp;4 in 1995 Chevrolet Cavalier Z24]]
For 1995 only, a balance shaft-equipped version of the 2.3-liter engine was produced. This arrangement ensures a constant load on the shafts: the crank drives one shaft, which drives the second, which then drives the [[Oil pump (internal combustion engine)|oil pump]]. The shafts spin at twice the engine [[Revolutions per minute|rpm]], forcing the [[redline]] to be reduced from 6800 to 6500&nbsp;rpm. Output is {{cvt|150|bhp|kW|0}} and {{cvt|150|lbft|Nm|0}}. This was the only Quad&nbsp;4 produced in 1995, and was known as a transitional year for the engine family.

Applications:
* 1995 [[Pontiac Sunfire]] GT
* 1995 [[Chevrolet Cavalier]] Z24
* 1995 [[Pontiac Grand Am]]
* 1995 [[Oldsmobile Achieva]]
* 1995 [[Buick Skylark]]
{{clear}}