6 cylinder engines 960

Применимость

B6244FS NEW Engine code 92

Cylinder volume 2,382 cc. Intended for Thailand only, to meet special tax regulations. Has 120 kW power output and approx. 215 Nm (preliminary data) of torque, bore 81 mm, stroke 77 mm, compression ratio 10.3:1 and modified pistons. Sold with automatic transmission AW43.

B6254FS NEW Engine code 93

Cylinder volume 2,473 cc. Power output 125 kW at 5,700 rpm and maximum torque of 230 Nm at 4,400 rpm. It differs from the 3 Liter engine in the following ways:

• Camshafts with lower maximum lift.
• Cylinder head gasket, pistons and cylinder bore adapted for cylinder diameter 81 mm instead of 83 mm. The cylinder liner thickness is increased by 1 mm.
• Crankshaft adapted for 80 mm stroke instead of 90 mm.
• Lowered compression ratio, 10.5:1 instead of 10.7:1.
• Adapted control modules for the Motronic engine management system as well as an automatic transmission.

Available with normal AW43 automatic transmission as well as an M90 manual transmission and a two mass flywheel. The final drive ratio is high: 4.10:1 for the AW43 and 3.91:1 for the M91, giving the engine a strong feel in the medium-speed range and in high gears.

B6304FS (1) Engine code 95

Previously used engine with 150 kW maximum power output and 267 Nm maximum torque.

B6304FS (2) NEW Engine code 96

Special version of the previous engine intended for USA/Canada. The torque curve has been moved down so that the engine is more powerful in those speed ranges used for normal driving. This flatter torque curve improves driving performance and the number of gear changes decreases. At approx. 2,400 rpm the torque is raised from approx. 225 Nm to approx. 250 Nm. Maximum power is approx. 135 kW at 4,100 rpm.These modifications have been obtained by altering the maximum lift of the camshafts as well as the program for the Motronic control module. The automatic transmission control module (TCM) has also been reprogrammed.

B6304GS Engine code 98

Previously engine in a G version, intended for markets with leaded gasoline

B6254GS NEW Engine code 99

Primarily the same engine as the B6254F, engine code 93, but in the G version intended for markets with leaded gasoline. As on the B6304GS there is no secondary air injection system, EGR or oxygen sensor (HO2S). The catalytic converter contains no precious metals and the mass air flow (MAF) sensor has an adjustment screw for CO. Sold with manual transmission M90 only.

General modifications to 6 cylinder engines

Extended replacement interval for the timing belt

The timing belt is widened from 23 to 28 mm on 6 cylinder engines and therefore the replacement interval can be extended to 120,000 km (in the USA 70,000 miles). All toothed belt components such as idler pulleys and toothed belt wheels are widened as is the timing gear cover. In order to ensure a long service life for the timing belt, the diameter of the toothed belt pulleys for the camshafts, crankshaft and water pump has also been increased. The new belt is thus wider and longer than the previous type.

Belt tensioner with lower tensioning force

To reduce noise a new belt tensioner that gives the belt lower force has been added. The check values for the timing belt should now lie in the 2.5-3.5 range. To reduce the noise level further every third tooth on the water pump wheel has been removed.

Modified auxiliaries installation

Since the timing belt assembly is 5 mm further forward, the drive pulleys for the auxiliaries have been moved forward by an equal amount. Since the air conditioning (A/C) compressor and crankshaft pulley are also larger diameter, the auxiliaries drive belt is new.

Single fuel pump

The main fuel pump under the rear floor is discontinued and replaced by a combined pre- and main pump mounted on the fuel level sensor in the tank, in the same manner as on the 850.

Modified idle air control (IAC) valve

The 6 cylinder have a larger idle air control (IAC) valve in order to admit more air to the engine. This is used in engine braking to reduce the vacuum and so reduce oil flow through the valve guides.

Modified injection mounting

The mounting of the injectors in the fuel distribution was modified during the spring by adding a rail that allows the injectors to be installed in only one position. The rubber rings between the manifold rail and the injectors and between injectors and intake manifolds were discontinued. This new mounting means that the special tools used to attach the injectors when the fuel distribution manifold is removed are not needed.

Modified mass air flow (MAF) sensor

The mass air flow (MAF) sensor has been modified by improving the support for the measuring duct and wires. The output signal for a given quantity of air is slightly different from the previous type of mass air flow (MAF) sensor neither the mass air flow (MAF) sensor or the control module is interchangeable with existing versions.

Modified oxygen sensor (HO2S) connection

The circuit for the oxygen sensor signal cable is no longer grounded through its screw mounting in the exhaust system but has a separate ground lead (to control module terminal 19) so that four cables run to the sensor as on the 850. This ensures a good earth irrespective of the condition of the exhaust system.

Pulse damper

The pressure hose to the fuel rail now contains a pulse damper to suppress noise generated as the two injector groups open and close.

Modified rear silencer

The exhaust system has a new silencer in order to give the engine sound a different character at lower engine speeds that better reflects the power of the 6 cylinder engines, at the same time as the exhaust sound is somewhat reduced at higher engine speeds.

Engine, miscellaneous

• During the spring a new black plastic fuel tank filler cap has replaced the earlier type on both the 940 and the 960.
• Because the new integrated relay/fusebox in the engine compartment takes up some space the air cleaner (ACL) cover and the fresh air intake have been altered.
• The California specification B6304S is now fitted with EV6 injectors, fitted to other 6 cylinder since 1993
• The Volvo 960 is only sold with 6 cylinder engines.