4A-GE Variants

"What's in a name?.."
Okay, kiddos... Do you know which 4A-GE you have in your car? You'll hear some people refer to 'em as a "red top" or "blue top" blah blah blah... These descriptions are taken from the color of the raised lettering on the valve covers. As the names imply, "red top" motors supposedly have some lettering in a red color; "blue top" motors have some lettering in blue. When motorheads (or the occasional riceboys) get together, they use these terms to let others know whether or not their 4A-GE has the stronger bottom end and high compression.

"So, why can't I use that terminology to describe which 4A-GE I have?"
Well, life would be much easier if we could stick to those descriptions alone, but the Toyota Motor Corporation decided to make our lives a little more interesting. See, over the lifespan of the 4A-GE, Toyota gradually changed the external (and some internal) parts--the new variations didn't follow any fixed time periods for their introduction. Also, different markets around the world sometimes got different engine assemblies (internal and/or external differences) than other markets during the same time period. Just think of the introduction and incorporation of the 4A-GE's over time as a "trickle effect" that eventually covered all markets, but not at the same rate. As such, you can't expect to see the same "top" during the same time period in different markets. For example, the earlier 4A-GE's (AE86 and AW11 chassis) mostly had valve covers with some blue lettering. Those engines still had the less robust bottom ends, big ports, and lower compression. But, some 4A-GE's that I've seen in AE92's have the same "blue top" even though Toyota started using the newer, stronger 4A-GE's--the only trait that changed when you compare the AW11/AE86 4A-GE to the '88-'89 AE92 4A-GE is the stronger bottom end. Big ports, T-VIS, compression? Yup, they're all the same. Toyota may have changed the ECU's ignition/fuel maps just a little bit, but they're all the same.

My AE92 and 4A-GE are one of the earliest production examples for this generation model--my car has a production date of September '87, which is just a month behind the first cars--ever seen an AE92 coupe with just lap belts in the rear seat instead of the 3-point belts? Well, that's how old my car is! I have a low compression (relatively speaking), T-VIS-equipped, big port, and stronger bottom end 4A-GE. Unfortunately, I don't have the nice oil squirters/piston coolers that Toyota made standard around Sept. of '89.

"Can't I still use that terminology as a general description?"
Sure, you can still use that as a general description, but don't be surprised when you and the person whom you're conversing with aren't agreeing on the details. Plus, it just lets the other person (assuming that they know better) know that you need to get more acquainted with your 4A-GE history. So, puh-leeze, don't use "red top" or "blue top" anymore.

"Yeah, yeah, Obi-Wan Kenobi... Show me the correct way..."
Okay, young padawan learner. When you refer to your engine, use the visible mechanical differences to describe your particular 4A-GE. For example, over the 4A-GE's lifespan, there are external differences on the block that you can readily see. Some variants have a noticeable plate that's sandwiched in between the head and the intake manifold (the T-VIS system along with a "name tag" affixed to the top of the manifold log). Some used either a MAP or AFM sensor to read the engine load (the amount of air getting into the engine)--but, we'll skip this characteristic because there are some 4A-GE's out there that have used MAP and AFM during the same time period depending on the market. Others had an external oil drain at the intake side of the head/block. Still, other differences aren't readily apparent unless the engine's disassembled. Read on and become enlightened. =)