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3800 ENGINE PERFORMANCE AND SPECIFICATIONS

IMPROVED PERFORMANCE FOR LN3 1988 3800 V6 ENGINE

VEHICLES AFFECTED: 1988 C, H AND E

The 1988 3800 LN3 engine takes the world's most proven V6 to new performance heights. Horsepower is up nearly 10% over 1987. Torque has increased up to 5%. Torque curve is expanded at the outer end for improved mid-range performance and higher RPM driving.- Maximum horsepower is now 165 hp @ 4800 RPM, and maximum torque is 210 lbs. ft. @ 2000 RPM.

Chief among the specific mechanical upgrades in the 3800 V6.are:

- 23 percent less reciprocating mass and a gear driven, balance shaft for improved smoothness.

- Repositioned fuel injectors and modified intake and exhaust porting for improved breathing and greater fuel economy.

- Transmission torque management control for improved transmission durability and shift smoothness.

- Precision machining plus lighter pistons and piston rings for reduced friction and better durability.

When an engine update was scheduled for 1988, the logical step's were to lengthen the block and shift the left side of the block forward and the right side rearward while revising the bore spacing appropriately. 'This placed the rods in the center line of the bore and on the center line of the piston. These seemingly simple changes produced a myriad of benefits.

First, the engine's reciprocating mass was reduced by some 23 percent, resulting in quicker throttle response and less vibration. Reduced piston friction from 30 percent lower ring tension resulted in improved fuel economy. Lengthening the block enabled B-O-C engineers to redesign the 3800's intake ports to ideally target the fuel injectors, permitting improved atomization and distribution for better cold start performance. An additional benefit was a substantial reduction in exhaust emissions. Simultaneously with these changes, the engine's cooling system was reconfigured resulting in increased combustion efficiency. Realignments in intake and exhaust port layout produced noticeably improved volumetric efficiency.

The 3800 V6 redesign incorporates a balance shaft, gear driven off the camshaft sprocket, that counterrotates at engine speed, eliminating first order primary imbalance. While the balance shaft results in significant gains in smoothness of the engine by itself, it also allowed B-O-C engineers to make further improvements in engine mounting systems. Dealing with significantly lowered vibrations, they could design engine mountings for smoothness over the whole range of engine and vehicle speeds.

The bottom line for all these enhancements is the best of both worlds - a 90 degree V6 engine that has the characteristics of a V8 but with the better fuel economy of a six.

Improved electronics technology also played a part in the development of the 3800 for 1988. GM's new GMP4 computer chip set, the virtual heart of the ECM (Electronic Control Module), offers much more capacity than the current chip set, thus allowing increased control of engine and transmission operation.

A digital EGR (Exhaust Gas Recirculation) system also helps performance by enabling more precise control of combustion, and aids smoothness by allowing less overlap in valve timing.

Electronics also permit a new concept called torque management which controls shift energy, minimizing - the impact of abusive shift maneuvers.

The torque management concept results in longer transmission life and smoother shifting by electronically reducing ignition spark for milliseconds during shifting and hard take offs, thereby increasing overall driveline life. Such things as the severe drive axle abuse typically encountered during reverse-to-drive-to-reverse shifting, as when trying to rock out of a snow- bank, are greatly diminished.

Additional engine improvements include a direct coupling of the all-new mass air flow sensor to the throttle body and intake manifold that greatly reduces the potential for unmetered air leakage. Also, a high-tech ignition system with a sensor connected directly to the crankshaft provides an extremely high resolution signal that is delivered to the ECM at 18 pulses per crankshaft revolution, and from there to the coil pack which fires the spark plugs through special wires designed to withstand thermal cycling.

In the 25 years since its introduction in 1962, the 90 degree V6 engine has become a widely used engine and a mainstay in GM passenger cars. From its start as a 198 cubic inch displacement engine developed from a small block V8, to the introduction of the evenfire crankshaft in 1978, multi-port fuel injection in 1985, and roller lifters in 1987, the 90 degree V6 has proven its reliability and versatility.

Now for 1988, with its increased horsepower, torque, fuel economy and smoothness, the 3800 V6 offers real proof of GM's continuing emphasis on improving the quality of driving.

The new 3800 engine for 1988 is standard on the Oldsmobile Ninety-Eight and Toronado, and is available vs. an option on the Delta 88.

3800 ENGINE ENHANCEMENTS

- Increased Torque and Horsepower output

- Greater Fuel Economy - over 1 MPG increase

- Balance Shaft added for improved smoothness

- 23% Less reciprocating Mass and Centered Rods to reduce rotating inertia

- Lighter Piston Ring loads to reduce friction

- O-Ring Gasketing to enhance engine sealability

- New Cylinder Heads with improved Fuel Injector Targeting and Porting to improve fueling response

- Fast-Start Ignition and Software Innovations for starting and driveability

- Engine/Transmission Torque Management Control to improve shift smoothness and reduce reverse to drive to reverse abuse

- A highly responsive and reliable integrated Mass Airflow Sensor and Throttle Body

- Expanded electronics with the high speed/high capacity GMP4 ECM Module having extended diagnostics capability plus many other integrated features

- Greater reliability and durability from design and processing/improvements in several areas such as Engine Accessories, Fastening, Metallurgy and Precision Machining

- Noticeable increases in performance and driver pleasability

- Digital EGR for more precise control

3800 ENGINE GENERAL SPECIFICATIONS ----------------------

Engine 3800 V6

Type Sequential Port Fuel Injected with Electronic Mass Air Flow measurement, 90 degree V6 arrangement with Balance Shaft, Electronic Computer Controlled Coil Ignition, EGR Valve, styled under- hood appearance.

Valve Arrangements Overhead Valve

Bore & Stroke 96.5 mm 86.4 mm (3.8 in x 3.4 in)

Displacement 3.8L (231 cu.in.)

Cylinder Head & Block Material Cast Iron

Compression Ratio 8.5:1

Net/Installed HP & Engine RPM 165 @ 4800

Net/Installed Torque (LB-FT) & Engine RPM 210 @ 2000

Recommended Fuel No Lead - 87 Octane

Fuel System Type Sequential Port Fuel Injection

Transmission Transverse Front Wheel Drive 4 Speed Automatic Type W/Torque Converter Clutch Lock-up in 3rd & 4th Gear Ratio First - 2.92 Second - 1.57 Third - 1.00 Fourth - .70 Reverse (R) - 2.38

Final Drive Ratios 2.73, 2.84, 2.97

Redline 6000 RPM

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