Information on a 3100 SFI V6 Engineby Rob Wagner
General Motors produced the 3100 SFI (Sequential Fuel Injection) V-6 engine for its cars from 1993 to 2003. Cars powered by this engine during those years included the Chevrolet Malibu, Pontiac Grand Prix and the Oldsmobile Cutlass Supreme.
Size and Construction
The 3100 SFI V-6 displaces 3.2 liters (191 cubic inches). It has a 3.51-inch cylinder bore and 3.31-inch stroke. The block is built from cast iron and the cylinder heads are cast aluminum.
This engine features a 9.6-to-1 compression ratio to develop 175 horsepower at 5,200 rpm and 195 foot-pounds of torque at 4,000 rpm. The ignition system is an electronic control module system with three coils and a remote timing senor. The alternator generates 105 amps at peak operation with 68 amps at idle. A sequential fuel injection system delivers 87-octane regular unleaded fuel to the engine.
Compatibility and Performance
GM matched the 3100 to a four-speed 4T65E automatic transmission with a first gear ratio of 2.92-to-1, second 1.57-to-1, 1.00-to-1 third and 0.71-to-1 fourth. When new, the engine was rated at 20 mpg in city driving and 30 mpg on country roads.