Background: Some time ago I picked up this running, driving, small rust spots on the outside, but immaculate interior, white car with about 300k miles on the clock for the low low price of "come pick it up and it's yours." Between obtaining it and when it was last parked, I sold off a couple of commuter cars that I had around and drove this daily for about 6 months. That's when the poor little 3AC (1.5L carbureted engine with 61hp, no that's not a typo sixty-one horsepower) gave up the ghost on the way home one hot Texas summer day, spewing oil everywhere; it still leaks in my driveway just sitting there untouched. It got me home though, but I just know the internals are not going to be in good shape after that and it was destined for more. In the 6 months I was driving it I even found a pristine condition and untouched Suzuki Swift in a junkyard to pull the TBI setup, computers, harness, etc. off of for a carb-to-TBI conversion, but alas it was not meant to be. On to bigger/torque-y-er things!

Some info on what makes this a little more out of the ordinary than a typical put-the-engine-back-together sort of thing: Nearly all car manufacturers have some sort of naming/designation system for their engines (and sometimes other components, but we won't touch on that just yet) as variations of each engines will be put in different models, trim levels, and/or meant for different purposes. Toyota, being wonderful, has a easy to understand and consistent naming convention along with a general policy of using each engine they develop in as many models as is possible opening options to parts interchangeability. So let's break down what the original engine, 3AC, and the new engine, 7AGE, names mean.

The number in Toyota engine nomenclature always stands for the iteration or generation of the engine. So the 3 in 3AC stand for the third iteration of the engine family (covered next) while the 7 in 7AGE, yep you guess it, stands for the 7th iteration. So by swapping from the 3AC to the 7AGE I'm jumping forward four iterations (and the technological progress associated) of this engine family.

The second character in this engine designates the family to which it belongs. In this case the A engine family, which consists of 4-cylinder, iron block, aluminum head engines; with the first iteration introduced in 1978 and the family of engines being produced until 2006. The family designation is not only important to find the base aspects, but also the general parts compatibility options. The Toyota A series engines ranged from as low as 1.3L to a high of 1.8L and, at least theoretically as every permutation hasn't been tried, being that they are in the same family one should be able to swap major part assemblies from one engine iteration to another. For example, of the eight generations of this engine, you should be able to take the first generation block (the lower portion of the engine that houses the crankshaft, pistons, and rods), put in a 5th generation crankshaft, 3rd generation pistons, 6th generation rods, and 4th generation head (top portion of engine that houses camshafts, valves, and moves the air into and out of an engine, more on this later), with little trouble and so long as you do your work with the associated parts to make them play nicely have a working engine that never existed prior. Now, while slapdash assembly of these random parts should work, that gives no guarantee that it's a good idea to use this combination and I just threw that out there as an example without checking things like piston-to-valve clearance, deck height, etc. so there's a solid chance that the random combo above will just slam a piston into the head the first time you try to start it ruining all your hard work. Families of engines can also broadly use transmissions from each other, so a car that came with a 2nd generation engine should be able to have an engine from the 7th generation attach directly to the 2nd generation car's transmission with little to no modification necessary to work. Which is, of course, key to my application.

The third character in these engine designations is where it starts to get interesting/complicated. For the original, 3AC, engine the third character is "C", but this is actually for the type of fueling the engine uses and so will correspond with the 4th character in the 7AGE engine which I'll cover next. All (or at least all that I can think of) modern inline engines use an OverHead Camshaft (OHC) design, meaning the camshaft that actuates the valves is on top of the head instead of inside the block and working via pushrods in OverHead Valve designs (as seen in many American V8 designs). Toyota did not use any letter designation for engines with a Single OverHead Camshaft (SOHC), making this essentially a blank space in the 3AC designation. So 3AC becomes 3A(blank-space-because-sohc-head)C. In what will seemingly further complicate matters (but actually simplifies it since Toyota exclusively uses Dual OHC engines now) is the two different types of head designations in DOHC engines. Toyota has F and G letters for this designation with F standing for the economical (read: fuel efficient) variant and G standing for the performance variant of the head design; for my engine the head design is the latter designation in 7AGE.

The final character tells you how the engine is fueled. In the case of the original engine the C in 3AC stand for carbureted (an older technology where a venturi is used to draw a metered amount of fuel into the engine) while the new engine uses electronic fuel injection as indicated by the E in 7AGE. There are other designations that aren't applicable here that fit into various spots in the engine code based the attribute such as high compression (older engines), turbocharging/supercharging, and Atkinson cycle hybrid engines.

So by now you're thinking "Thanks, but that seems like an unnecessarily long way to say you're going from a 3rd generation engine to a 7th generation engine." Well... not exactly. You see, the 7AGE model engine doesn't actually exist in the original context of Toyota engines. Toyota only ever made a 7AFE engine, a 1.8L fuel efficient mill meant for commuter cars like the Corolla. "So where does the G performance designation come from?" you (quite likely did not) ask? From the 4th generation of the engine family! Isn't this fun?! - Of the A series engine family, the 4th generation is the most famous. The 4th generation was the only one that had a performance variant and was used in the 80's MR2, the Formula Atlantic open wheel race series, and if you're an manga/anime fan it's the engine used in Takumi Fujiwara's AE86 Corolla drift car from the Initial D series. It's an extremely robust, capable, compact, and high revving 1.6L DOHC engine that made very good power for the time, is still no slouch today, and is still sought after by many.

Remember what I said about engine family parts interchangeability? Yep, that's how this works. I'm going from the original 1.5L SOHC, carbureted, eight valve engine to a 1.8L DOHC, fuel injected, sixteen valve engine by combining parts from the 7th generation, 3rd generation, three iterations of the 4th generation, and a Peugeot engine to make a "big block" Toyota 4 cylinder engine that will effortlessly more than double the power of the original engine and still bolt up to the only-available-in-this-model transmission. This engine's major components consist of a 1.8L 7AFE shortblock (bottom end) from a 1995 Toyota Celica ($250 shipped to my door), 4AGE "smallport" high compression pistons from a 1991 Toyota Corolla GTS, 4AGE high flow oil pump the 1995 Toyota Corolla, 4AGE "bigport" head from a 1985 Toyota MR2 ($75 from a guy I stalked at a donut shop, long story), 3AC oil pan and pickup (because special transmission needs oil pan from original engine, with an adapter, to fit) along with flywheel because it's smaller than other gens to fit in the special transmission, and a timing belt (with a rebroached Toyota timing gear) from a late 80's Peugeot 505 because the tooth count and profile matches what is needed with the higher deck of the bigger block and the new high flow oil pump.