The New Engine Decision
So I needed a new engine. I could have done a straight swap for a 4A-GE 16v but 2nd hand ones are getting on with high mileage and a bit ropey now, I'd need a rebuilt one. There is a blue top (big port) with 112bhp, this is the standard AE86 engine. There is a red top (small port) 4AGE version which came in the AE92 with 130bhp. If I needed to go to work to change an engine, I thought now would be the time to do a conversion, so I looked at alternatives too.
Engine conversions for the AE86 is virtually limitless now. I have seen 240bhp S2000 engines put in, V8 1JZE's, Even a very long straight 6 supra twin turbo engine put in (requiring elongation of the bodywork). As I had basic fabrication skills, none of these really appealed due to the work required, I didn't even consider them for that reason.
Fortunately the 4A series is a long term engine with lots of variations. On top of the 16v varients, there is 20v silvertop with 165bhp and 20v blacktop with 170bhp. There is several supercharged versions from 145bhp-165bhp. Or the most desired Formula Atlantic spec N/A 16v with 240bhp revving to over 10k rpm.
I ruled out the Formula Atlantic engine due to lack of support, availability, life span (needs rebuilding every few thousand miles) and of course the price. The options left gave me a 20v high revving, glorious sounding engine, or a torque packed supercharge whineing block. the 4AGZE's are still 16v so mount easier in the AE86 chassis, and have more tuning potential as the internals are forged, a future turbo swap wouldn't require opening of the engine if desired, a few more conversion bits would be needed for a 20V and for these reasons I decided to go for a 4AGZE.
The 4AGZE Decision
Further research showed I had to make another decision, there is actually 4 varients of the 4AGZE from different cars.
1. From the original mk1 MR2 AW11 was a 4AGZE with 145bhp, an air flow meter (AFM) and the sparks operated by a traditional distributer.
2. The AE92 Corolla in early 4AGZE form maintained the AFM but got rid of the Distributer for distribution less ignition (DLI). I believe this was around the 145bhp mark still.
3. Later version of the AE92 Corolla had a 4AGZE with the new DLI still but with electronics evolving got rid of the AFM and replaced with a manifold absolute pressure (MAP) sensor. This was far superior from the AFM and the power got up to the 160bhp mark.
4. The 4AGZE was last used in the AE101 Corolla alongside the 20v 4AGE. This came with the DLI and MAP sensor upgrades with a few more tweeks boasted 165bhp. Due to Honda's VTEC system, N/A engines were more popular in Japan so the AE111 Corolla did not have a 4AGZE but kept the better selling 20v engine.
I wasn't keen on the phase 1 engine as they were getting old now too just like the blue top 16v, it was a late 80s engine afterall. Any of the others will do so I'd have the first that came available.
A few months passed and I had no luck finding one. A engine importer said he'd have one I just had to wait, it was always 'on the next shipment', it never was though.
More searching and I came up with a Malaysian engine builder specialising in 4AGE's, result! Not only that he had all versions of the 4AGZE in stock and rebuilt them for customers and modified for different applications. Didn't take long for me to make an order, with a small different between the phase 1 4AGZE and phase 4 4AGZE I went for the latest one, and so the project was back on track.
