TOYOTA TWIN CAM
Toyota Twin-Cam Evolution
Toyota is the largest producer of Twin Cam engines. Toyota offers more Twin Cam models than any other manufacturer.
The earliest and rarest production Toyota Twin Cam engines were the 3M and 9R. Both engines were produced during 1966 to 1969, and ironically did not carry G engine designations. The 3M was a 2 valve Twin Cam 6 cylinder engine with triple Mikunis used in the Toyota 2000 GT. The same generic M block, modified through the years became the 2M/4M/5MG/6MG/7MG engines- with totally different heads and crankshafts. The 9R was a 2 valve Twin Cam 4 cylinder with twin Mikunis used in the Corona 1600GT. The R block was Toyotas generic 4 cylinder blocks in the 60’s. Carrying different alpha numeric designations- the R blocks were actually a series of totally different blocks.
The Toyota 2000GT established many time/distance endurance records. In 1968 Carrol Shelby entered some SCCA events with 2-cars. The Corona 1600 GT was the original Sport Compact. When introduced, the package was unrivalled and unmatched by any other Japanese manufacturer. The production runs on the 3M and 9R engines were limited, but it showed Toyota the advantage of the Twin Cam design.
The 2TG and 18RG were the original mass-production Toyota Twin Cam engines. At introduction, these were the most widely available and produced Twin Cam engines for production cars in the whole world. The use of these engines in local (Japan) and regional (Asian) competition saw many major victories for Toyota world-wide and at this early time predicted Toyota’s future claim as a Technology Driven company.
The 2TG was introduced in Japan 1970 for the
Corolla / Sprinter series in Japan. It was available in various forms (through
the years) until 1984. The 1600cc 2TG came with twin-side Mikunis in 2TG, 2TGR,
and 2TGU models. Eventually it came with fuel injection as a 2TGEU. The last
model in this series engine was the 3TGTE. TRD and the aftermarket provided
many parts and 1750cc / 2000 cc conversions were extremely popular.
The 18RG was first introduced as an 8RG and as an interim 10RG (both 1968cc) in 1971 for the Celica GT models and the Mark II GSS, respectively. The 2000cc 18RG came out in 1974 with twin-side Mikunis in 18RG, 18RGR, and 18RGU models. Eventually it came with fuel injection as an 18RGEU. In the US, these were popular upgrades in Celicas and Toyota Pick-ups. The 2200cc conversion was very popular and some were even setup as 2400cc. Toyota also produced a limited number of twin-plug 18RGs that never reached production.
The 3TGTE replaced the 18RGEU in the Celicas in 1983. The 3TGTE (1770cc), a twin-plug version of the classic and trouble-free 8-valve 2TG / 18RG cylinder head had a CT20 Turbo, a proprietary Toyota design. The 4TGTE homologation version for Toyota's Group B Rally Car had different pistons and crankshaft. This engine took Championship honors in the FIA World Rally Cup Group B SuperCar series. .
These engines were never imported by Toyota USA. Through Toysport importations, these engines became very popular in all the Corollas, Carinas, Celicas, dune buggies, and Lotus 7 replicas.
The 2nd generation six-cylinder Twin Cam 5MG 2800 and 6MG 3000 arrived 1982, more than a decade after the 3M. The towering cam position looked impressive. The new Twin Cam head-design had innovative self-adjusting hydraulic lifters that required no extra maintenance for valve adjustment. Service simplicity allowed Toyota to use the engines on many high performance sedans, aside from the Supra and Soarer. This marked a significant step for Toyota, the first Twin Cams six available across the whole model range.
In Toyota-techno talk, the numerous letter designations quickly identify engine types. After the basic alpha/numeric engine family identification: G denotes twin cam “sport”; R for “regular gas”; U for ‘unleaded” meaning emission controlled; T for turbo; Z for Supercharger; E for fuel injection.
Directly transferred from racing activities, the 4 valve technology provided an opportunity for a simultaneous evolution of Toyota cylinder blocks and heads. (Prior to this point all Toyota blocks were basically the 1st generation blocks Toyota had for the different displacement and cylinder configurations: 4-cylinder K- under 1200, T- under 1600, R- under 2000; 6 cylinder M- 2000 and up. Ultimately, the K- evolved to 1800, the T to 1800, the R to 2400, and the M to 3000.)
In 1984, the 4th generation 4 valve Toyota Twin Cams, 4AGE/16 and 1GGE/24 were released. Originally designated as “Laser” lightweight series, significant changes were also made on the engine blocks- compact design, thin wall casting, and lightweight crankshafts. Fortunately Toyota decided against aluminum alloy cylinder blocks! The 4AGE 1600 16 Valve was followed by a 4AGZE supercharged model. Likewise, the 1GGE 2000 24 Valve also had a supercharged version 1GGZE / turbocharged 1GGTE. All these engines had “later” model versions, with port reconfiguration and piston changes for more HP.
In 1986, the 3SG 2000 and 7MG 3000 filled in the updated 4-valve engine range. Both models were followed by turbocharged versions 3SGTE and 7MGTE. The 3SGE/TE also had “later” models versions, with port reconfiguration and piston changes for more HP.
In 1990 the M block was finally replaced by the 1JZGE 2500 / 2JZGE 3000. With totally new bore / stroke configurations and further advanced thin wall casting and lightweight crankshafts- the long awaited “state-of-art” Toyota six cylinder Twin Cams finally arrived. Naturally the Turbo models1JZGTE / 2JZTGE supplemented the base models. As a tribute to Toyota engineers- the aftermarket reacted strongly and the performance envelope reached new heights- close to 800 HP capabilities on stock internals!
F Type High-Torque
The continuous development of the G Type Sport Twin Cam engines is complemented with applications for the more sedate sedans. A new Twin Cam design, F Type denoting “four valve” was introduced in 1987. This replaced all the SOHC (single overhead cam) heads on the E, A, and S block engines. The F heads are “narrow” Twin Cams that provided improved performance to compensate for emission regulations; and were tuned specifically for quick RPM response / high torque. A notable exception is the 4EFTE engine- it is the only “sport” engine using an F-Type head. The E series replaced the K engines in the under 1500cc class for car appliocations.
All subsequent new Toyota engines: the NZ (under 1500cc), the RZ and TZ (above 2000cc) 4 cylinder engines; the MZ V6 and UZ V8, were all introduced with F Type Twin Cam heads and were subsequently upgraded to VVT specification. Most of the current Toyota engines use an F type cylinder head, enabling Toyota to continue the claim- world's leading supplier of the Twin Cam engine design. and the V6 and V8s.
Variable Timing +
In 1992, the 4AGE 1600 received VVT (Variable Cam Timing), individual throttle bodies, and an extra Valve > 4AGE 20V! It produced 160 HP, the equivalent of 10 HP for every 100cc- racing engine output comparable to the early days of Twin Cams! By 1997, the JZ six cylinder models and the 3SGE Beams gained VVT heads too.
In it’s final reiteration the 3SGE gained Dual VVTi head and remains in production for the Altezza. The 3SGTE never had the VVTi head, but internal upgrades and different turbos allowed it to produce 260 HP.
The 2ZZGE 1800 is the newest and maybe LAST G series Twin Cam engine. The use of aluminum blocks is also a first for a Toyota performance engine. Up-graded features include variable timing and variable lift, and tuned intake manifold.
The Yamaha connection needs to be mentioned: Yamaha developed the Toyota 2000GT and was a Toyota partner in the design of most Type G heads. Most engines/heads, including the 3SGE/3SGTE (now in it's 4th generation), the Previa specific 2TZFE/Z (no relation to the old T engines), and the newest 2ZZGE engines were and are still designed and cast by Yamaha. Yamaha also assembles most of the Toyota G model engines.
(The 4AGE and 2JZGE heads are proprietary
Toyota designs and manufacture, although many components are still made and
supplied by Yamaha).
The classic Twin Cam design has worked very well for Toyota and has powered all milestone Toyota performance models. The current generation multi-valve / variable cam timing G Type Twin Cam 2JZGE, 3SGE, 2ZZGE engines showcase the ultimate evolution of Toyota performance engines; and the F Type engines, for the rest of Toyota’s fleet, powers the Scion and Lexus models too.
No other manufacturer can claim over-all superiority on production based Twin Cam engines. Although other manufacturers exploit the benefits of Twin Cam technology further, the Toyota engine has proven more durable bar none.
The Toyota Twin
Cam engines has been produced in more variations: 1000cc to 5700cc; 2 or 4 or 5
valves per cylinder; normally-aspirated, turbocharged, and supercharged.
Future Hybrid Twin Cam
Toyota Twin Cam engines will remain in the forefront of Toyota technology. With all current Toyota engines featuring Twin Cam head configurations of either Type F or G variety, it is assured that a Toyota Twin Cam will continue to power future Toyotas. The Prius 1NZFXE 1500cc proved Twin Cam compatibility for Hybrid applications. The new 3MZFE 3300cc has already been combined with Dual electric motors in engineering studies. “Electric Supercharger” is the operative term for the future.
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