The 3S-GTE is an in-line 4-cylinder 1998cc engine from Toyota, based on the 3S-GE with reduced compression ratio and addition of a turbocharger.
There are four generations of this engine, which were manufactured from 1986 to 2007.
| 3S-GTE Engines | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Generation | Years | Compr. | Power (Japan) | Torque | Used In | ||||
| 1st | 1986–1989 | 8.5:1 | 136 kW (182 hp) @6000 rpm | 250 Nm (184 ft·lbf) @3600 rpm | Celica GT-Four (ST165) | ||||
| 2nd | 1990–1993 | 8.8:1 | 165 kW (221 hp) @6000 rpm | 304 Nm (224 ft·lbf) @3200 rpm | Celica GT-Four (ST185), MR2 (SW20) | ||||
| 3rd | 1994–1999 | 8.5:1 | 180 kW (241 hp) @6000 rpm | 304 Nm (224 ft·lbf) @4000 rpm | Celica GT-Four (ST205), MR2 (SW20) | ||||
| 4th | 1999–2007 | 9.0:1 | 191 kW (256 hp) @6200 rpm | 324 Nm (239 ft·lbf) @4400 rpm | Caldina GT-T (ST215), Caldina GT-Four (ST246) | ||||
The turbochargers used in the 3S-GTE engines are Toyota designs. The first generation Toyota CT26 utilized a single entry turbine housing and a single wastegate port design. The second generation Toyota CT26 used a twin entry turbine housing with dual wastegate ports. The third-generation engine uses the (enthusiast-dubbed) Toyota CT20b turbo which was of the same design as the second generation but with a slightly improved turbine housing. The fourth generation engine uses a proprietary CT15b turbocharger whose exhaust housing is actually cast into the exhaust manifold, rather than the normal practice of a separate turbine housing after the cylinder exhaust manifold. The CT20b can be used on the second generation 3S-GTE head but it is not backwards compatible with the first generation 3S-GTE. The CT15b is backwards compatible with the third generation 3S-GTE cylinder head only. All Toyota's turbochargers for the 3S-GTE generations use an internal wastegate design.
Depending on where the engine was intended to be sold the exhaust turbine is either ceramic (Japanese) or steel (US). It was fitted to the MR2, Toyota Celica GT-Four, and the Caldina. Its cylinders are numbered 1-2-3-4, cylinder number 1 is beside the timing belt. The dual overhead cam (DOHC) 16 valve cylinder head designed by Yamaha is made of aluminum alloy. The pent-roof combustion chambers are complemented by a crossflow intake and exhaust layout. Spark plugs are located in the middle of the combustion chambers. A distributor based system is used to fire the cylinders in a 1-3-4-2 order.
The first and third Celica generation intake charge was cooled by a water-to-air intercooler while the second, third MR2, and fourth generation relied on an air-to-air system. Also, the second generation rally homologation Celica GT-Four (known as Group A Rallye in Australia, RC in Japan and Carlos Sainz Limited Edition in Europe) used a water-to-air intercooler.
The crankshaft, located within the crankcase, rotates on five aluminum 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 various other components.
On the first two generations the intake manifold has eight independent ports and benefits from the inertia build-up to improve engine torque at low and medium speeds. Due to the design of the intake manifold, cylinder number 3 runs lean under normal operation. Various aftermarket solutions exist all of which require replacing the intake headers or manifold. The first two generations of 3S-GTE engines are equipped with TVIS. The third generation uses a normal four-runner intake manifold. In fourth generation, intake manifold design was improved even further. Turbocharger turbine housing was combined with exhaust manifold [1]
A single timing belt drives the intake and exhaust camshaft along with the oil and water pumps. The cam journal is supported on five points between the valve lifters of each cylinder and on the front of the cylinder head. The cam journals are lubricated by oiler port located in the middle of the camshaft.
To adjust the valve clearance, adjust the shims above the valve lifters (shim over bucket system). This allows for the replacement of the shims without the need to remove the camshaft.
The pistons are made from an aluminum alloy, design to withstand high temperatures. An indentation is incorporated into the pistons to prevent the pistons from "knocking" into the valves. The compression ratio is 8.5:1 for the first and third generation and 8.8:1 for the second generation. Piston pins holding the pistons in place are locked by snap rings.
The first compression ring and the oil ring is made of steel, the second compression ring is made of cast iron. Compression ring 1 and 2, prevents gas leakages from the combustion chamber while the oil ring works to clear oil off the cylinder walls, preventing any excessive oil from entering the combustion chamber.
The cast iron cylinder block holds four 86mm pistons and has a stroke of 86mm. Built into the cylinder block are coolant channels, which cools the block which houses the crankshaft.
At the bottom of the cylinder block is an oil pan which stores the oil. A panel is used to ensure that there are sufficient oil available in the oil pan, as the oil moves around the reservoir during movement of the vehicle. This prevents oil from being shifted away from the oil pump suction pipe.