The Toyota 3S-GE (originally titled 3S-GELU’ in transversely-mounted applications with Japanese emission controls), is an in-line 4 cylinder engine in the S engine family, manufactured by Toyota and designed in conjunction with Yamaha. While the block is iron, the cylinder head is made of aluminium alloy. The pent-roof combustion chambers are complemented by a cross-flow intake and exhaust layout. The spark plug is located in the center of the combustion chamber. The firing order is 1-3-4-2, with cylinder number 1 adjacent to the timing belt. The 3S-GE was designed to be light, the first iteration 3S-GELU weighing in at a low 143 kg (315 lb).
The forged crankshaft, located within the crankcase, rotates on five aluminium alloy bearings and is balanced by eight weights. Oil holes are located in the middle of the crankshaft to provide oil to the connecting rods, bearing, pistons and other moving components. The intake manifold has four independent ports and benefits from inertia build up to improve engine torque at low and medium speeds.
A single timing belt drives the intake and exhaust camshaft. The cam journals are supported on five points between the valve lifters of each cylinder and on the front of the cylinder head, and are lubricated by an oiler port located in the middle of the camshaft.
The pistons are made from an aluminium alloy, designed to withstand high temperatures. An indentation is incorporated into the piston head to prevent the pistons from hitting the valves, should the timing belt break (this is not true of the later BEAMS – an acronym which stands for Breakthrough Engine with Advanced Mechanism System – motors). This is commonly referred to as a “non-interference” engine. Piston pins holding the pistons in place are locked by snap rings. The “Outer Shim Type System” allows for the replacement of the shims without the need to remove the camshaft. To adjust the valve clearance, adjust the shims above the valve lifters.
The first compression ring and the oil ring are made of steel, the second compression ring is made of cast iron. Compression rings 1 and 2 prevent exhaust leakage from the combustion chamber while the oil ring works to clear oil off the cylinder walls, preventing excessive oil from entering the combustion chamber. An oil pan baffle is used to ensure that there is sufficient oil available in the oil pan.
There are five generations of the 3S-GE, which were used in the Toyota Celica, MR2, Caldina, RAV4, and Altezza. All 3S-GE engines had a displacement of 2.0 L (1,998 cc). Additionally, the turbocharged 3S-GTE engines are based on the 3S-GE platform.
The first-generation 3S-GE was produced from May 1984 to 1989, arriving in both Northern American versions, as well as In Japan as a second variation. The Northern American engine was slightly less powerful, producing around 135 bhp (101 kW). This engine was the only 3S-GE to come to North America, in the Celica GT-S (ST162). Among other things, the Japanese market version sported a more aggressive ECU and lacked the EGR valve system, pushing the output to somewhere around 160 PS (118 kW) at 6,400 rpm and 19.0 kg•m (186 N•m) of torque. The engine was originally available in particular in the Toyota Camry/Vista Twin Cam 2000 (3S-GELU for V10s, 3S-GE for V20s) and Toyota Corona *T150 (limited chassis version – ST162 with 3S-GELU).
The second generation was produced from 1990 to 1993, receiving a slight boost in output to 165 PS (121 kW), 156 PS (115 kW) in European markets. Peak torque went to 19.5 kg•m (191 N•m). It also proved to be a slightly more reliable engine. The second generation also did away with the T-VIS system, which was replaced by the ACIS (Acoustic Control Induction System), proving to be much more efficient. T-VIS was, however, retained on the second-generation 3S-GTE, the turbocharged counterpart.
The third-generation 3S-GE was produced from 1994 to 1999. Power output for the Japanese market was increased to 180 PS (132 kW; 178 hp) as the compression ratio was increased to 10.3:1, while motors for other markets received a minor revision in 1996 for emissions (EGR) which reduced power output slightly to 170 PS (125 kW; 168 hp) at 7,000 rpm. Torque remains the same for both at 19.5 kg•m (191 N•m).
The fourth-generation 3S-GE, also known as the ‘Red Top BEAMS’ 3S-GE began production in 1997. BEAMS is an acronym which stands for Breakthrough Engine with Advanced Mechanism System.
The first version was equipped with VVT-i and produced 200 PS (147 kW; 197 hp) at 7,000 rpm when coupled to a manual transmission. The automatic version produced 190 PS (140 kW; 187 bhp) at 7000 rpm; this is believed to be an ECU restriction implemented by Toyota due to gearbox limitations. It was available in a few models sold only in Japan: the MR2 G and G-Limited, the Celica ST202 SS-II and SS-III and the Caldina.
The second version generation 4 3S-GE, the ‘Grey Top BEAMS’ 3S-GE, was an available engine option in the RAV4 and second-generation Caldina Active Sports GT in Japan. Even though the valve cover on this engine is black, it is referred to as the “Grey Top”, taking its name from the grey intake plenum colouring. This naming is as such to differentiate it from the fifth-generation Dual-VVTi “Black Top” in the Altezza. Power output is 180 PS (132 kW; 178 hp) at 6,600 rpm in the RAV4 and 190 PS (140 kW; 187 hp) in the Caldina GT. The mechanical differences between the Red Top and Grey Top is the headers and the ECU. Wiring is identical.
Casting provisions exist in the heads for Exhaust VVT solenoid, and RWD water gallery is open, behind the altinator mount. Rear oil drain at the back of the head is in a different position.
Gen 4 also runs a manual throttle body.
This engine was used in some TTE WRC Corollas (modified for Turbo).
BEAMS 3S-GE 5th-generation engine (“Black Top”)
In 1998, the fifth version of the 3S-GE was released, found only in the Japanese-delivered Altezza RS200. The ‘Black Top’ as it came to be referred to as, was fitted with a dual VVT-i system that adjusted timing on both intake and exhaust camshafts and came in two different spec levels dependent on which transmission it was coupled to.
Gen 5 uses electronic controlled throttle with cable (semi-drive by wire), so no idle speed controller is required. A returnless fuel rail is also used.
The MT version that came equipped with the J160 6-speed manual transmission featured larger diameter titanium intake valves measuring 35mm, larger exhaust valves measuring 29.5mm also made from titanium, a larger 33mm bucket and a compression ratio of 11.5:1. It made 210 PS (154 kW; 207 hp) at 7,600 rpm and 22.0 kg•m (216 N•m) at 6,400 rpm.
Compared to the MT version, the 5-speed AT version came equipped with the A650E Tiptronic automatic transmission and had a lower compression ratio of 11.1:1, a less aggressive cam profile, smaller steel-alloy valves and smaller 31mm buckets. This engine made 200 PS (147 kW; 197 hp) at 7,000 rpm and 22.0 kg•m (216 N•m) at a considerably lower 4,800 rpm. Externally, the AT model can be identified by differences in the wiring loom and the lack of an acoustic blanket on the intake plenum.