The Story of the 4AGE || Part I

Let’s talk about one of Toyota’s most famous engines, its evolution, and some of its interesting attributes - the 4age! It started life in 1983 and was produced until 1998. Let’s break down its naming convention. The “4” means the 4th revision of the A block. The “G” indicates it’s a performance cylinder head and the “E” is for electronic fuel injection. The first instances of the 4A engine family were far less impressive and performance-oriented than the almighty 4age, the first engine being the 4ac, used a carbureted single overhead cam 8valve platform, outputting around 70 hp. The next evolution of the 4A family was the 4AFE which introduced double-overhead cams and fuel injection. Soon after, the 4AGE was the performance option for the Corolla, Celica, MR2, and other midsize Toyota vehicles of the time. You can also find the 4age in the Geo Prizm and Chevrolet Nova, which are basically rebadged versions of the Corolla AE92. When it comes to the power output of the 4age, it started with 112hp in its first iteration and bumped up to 165 hp in its final generation. Fact: The 4age shares a lot with the Cosworth BDA. For those that don’t know, BDA means Belt-Drive Series A. It was one of the first racing and production engines to have both cam gears driven by a rubber-toothed belt. The 4age was also Toyota's first engine to have both cam gears driven by a rubber-toothed belt.
If you, like me, spent your teenage years watching the Initial D anime, you'd be familiar with that throaty, zingy, and glorious howl of the Toyota AE86 Trueno belonging to Takumi Fujiwara. Well, that howl, is real, and it comes from Toyota's legendary 4A-GE series of engines.
The first three generations of the 4A-GE utilized a 16-valve cylinder head. The first of the three is called the Blue Top (Early Bigport). This came out in 1983 as a replacement for Toyota's 2T-G engines. It was recognizable from the silver cam cover with black and blue letterings, plus three reinforcement ribs on the back of the engine block.
In the Japanese versions, where a manifold absolute pressure (MAP) sensor is used instead, output was 120 PS and 142 Nm, paltry by today's standards. But, the 120 PS was made at 6,000 rpm, which tells you about the rev-happy nature of this engine and powered the AE86 that weighed no more than a tonne. Furthermore, it is 15% lighter than its predecessor, the 2T-GEU. The 'bigport' nickname came from the large cross-section area in the intake ports. This meant good airflow at high engine speeds, but low-rev lethargy. To counter this, Toyota Variable Induction System, (T-VIS) was introduced to optimize airflow at low engine speeds. The Blue Top ended production in 1987. The second-generation Red & Black Top (Late Bigport) took over and brought larger diameter bearings for the connecting rods. The updated engine is also stronger thanks to seven reinforcement ribs on the back of the engine block, up from three.
T-VIS and AFM/MAP (market dependent) stayed on, but this second generation was only produced unitl 1988. Output remained largely the same as the earlier Blue Top. Then came the final iteration of the 16-valve 4A-GE, the Red Top (Smallport). Compression ratio for this engine was raised from 9.4: 1 to 10.3: 1. The 'smallport' name? Well, the intake ports were redesigned to a smaller cross-section, thus negating the need for T-VIS. Improvements to the engine design saw US (AFM) versions put out 125 PS and 149 Nm, with Japanese versions (MAP sensor) making 10 PS more. The Red Top was produced up until 1992, when a whole new cylinder head was introduced. The fourth-generation 4A-GE (1991 to 1995), is also the first-generation of the 20-valve ones (confused yet?). The Silver Top was named as such because.... well it had a silver cam cover with chrome letterings (thanks Sherlock). It brought even more improvements to eke out even more performance. 5 valves per cylinder, variable valve timing (intake side), higher compression ratio (10.5:1). Best of all, it ditched the old intake manifold and replaced it with individual throttle bodies. The result? Supreme throttle response and driveablity, in a package that still loved to rev. 157 PS now came at a heady 7,400 rpm, along with 162 Nm at 5,200 rpm. Curiously, the Silver Top retained the vane-type AFM system employed previously in American-market 16-valve 4A-GEs. This necessitated a plenum, with intake ports that are far more upright than the curved ones in the 16-valve units. And onto the crown jewel of the 4A-GE family (1995 to 2000), the final iteration of the lineage and also the most magnificent one, the Black Top 20-valve. Once again, the name is pretty self-explanatory (black cam cover, black letters, carry on Holmes).