REMOVING THE OLD ENGINE

We backed the car into it's bay where it would be sitting for a few days. First up the brackets at the bottom of the bonnet were unbolted, and the bonnet was removed. We then went through the engine bay unbolting and removing everything that would need to go to get the old engine out and the new one in. This included removing the air filter, air flow meter and inlet piping, the old coil and igniter, heater hoses going into the cabin, accelerator cable, strut brace and water reservoirs. We also drained the radiator and removed the radiator hoses and the radiator itself.

Next up all the engine wiring from the 20v had to be removed. We went through and unplugged everything from the engine. Each plug was clearly labeled, which should make life easier when the 20v is installed into it's next home (possibly an AE86, when my bank account recovers). We stripped the engine loom of most of it's convaluted tubing and electrical tape, so that it could be seperated from the car's orginal "accessories" wiring loom. This was actually quite easy, as there were only few wires from the 20v loom that had been spliced into the original loom - the wires were cut and labeled, and the 20v loom was unplugged from the ECU and pulled through the firewall. The computer itself was also removed from it's location below the dash at this stage.

The power steering pump and the air con compressor were unbolted from their brackets and swung out the way, so the engine could be removed without the need for a re-gas. We also removed the heat shield from the exhaust manifold and unbolted the manifold from the 20v's head.

The front end of the car was then jacked up and put on stands. The wheels were the next thing to come off the car, then off came the discs & hubs and the calipers were swung out of the way. The driveshafts then came out, along with a few litres of transmission oil. At this point the wheels were put back on and the car lowered back down. The engine crane was wheeled into place and linked onto the engine's lifting hooks. We jacked up the crane very slightly to take the weight off the mounting points of the engine, then went around and removed the bolts from each of the engine and gearbox mounts. Once these were out of the way, the 20v (with the g/box still attached) was able to swing freely, and was manouvred out of the engine bay and lowered onto an old tyre.

We now needed to remove the exhaust manifold, so a pipe cutter was used to seperate the factory 20v headers after the point where they join the single exhaust pipe. The whole lot was then pulled out from underneath.

That was enough work for one day.

INSTALLING THE NEW ENGINE

Tuesday morning was another early start - it's amazing how much you can achieve in one day if you start at 7am and keep working 'til after dark!

First job was to seperate the gearbox from the old engine - as the 20v gearbox was in decent condition and would bolt up to the 4A-GZE, we decided to use it to get the car running, and replace it with a stronger LSD-equipped gearbox sometime down the track. After splitting the g/box from the 20v, we found the clutch to be fairly worn, but decided to use it for the time being as the g/box was to be replaced at some stage anyway.

As the 4A-GZE was bought as a bare engine, the ancilleries from the 20v had to be removed so they could be transplanted onto the GZE. The bracketry and layout of ancilleries we had on the 20v was quite different to the GZE - which normally has the power steering pump, air con compresser and alternator all mounted on the right side (looking at the crank pulley) of the engine. This would not suit my setup, as we were using a distributor in place of the standard GZE Crank Angle Sensor, which would not allow the p/s pump to fit in it's normal location. We therefore decided to swap all the brackets over from the 20v (which originally came from my old 4A-FC) which, thankfully, will all bolt up to the 4A-GZE (note that the use of some spacers may be required). So, when looking from the front (crank pulley side) of the engine, you have the following: left side- power steering pump down low, right side- air con down low, alternator above it and below distributor.

Paul spent some time sorting out the above on the engine stand, whilst Shane F (Twincam16) and myself started on the wiring. A good part of that day was spent tracing through loom of the Microtech ECU trying to work out exactly what was what - most of it was pretty straight forward, but it was a little difficult trying to work out the ignition wiring without the help of a manual! (remember i bought the Microtech second-hand). We ended up getting on the phone to Microtech, who kindly informed we would need an extra Bosch ignition module for this setup - we organised to get this sent up (they're in NSW) and also a copy of the wiring diagram faxed through.

By this time the engine was ready to be dropped into place in the engine bay. We hooked up the crane, removed the GZE from the engine stand and dropped it onto a tyre in front of the car. We bolted up the 20v flywheel and aligned the clutch, then bolted on the 20v gearbox. I also took the opportunity to fit a new starter motor, as the old one had been playing up for the last couple of weeks. The 20v gearbox has a spot on each side of it to fit the starter, we had to use the back because of the turbo sitting in that very spot on the front :)

The engine and gearbox combination was hoisted into the air, swung over the corolla's engine bay, then, with a bit of twisting and shoving, lowered into place. The bolts go into the mounts, and everything is looking good! Time for some sleep.

Another early morning. The next step was to start hooking up the ancilleries. The engine alread had the inlet manifold, exhaust manifold, turbo and distributor bolted up when we dropped it into place. I used the brackets we had swapped over onto the GZE to bolt on the power steering pump and the air con compressor, both of which remained in the engine bay from the previous engine. Next I set to work bolting in bits and pieces including the coil, radiator, gear shift linkages, hooking up water hoses, heater hoses, fuel lines and vacuum lines for the brake booster, BOV, fuel regulator and boost guage. A new 9" fan was also installed on the front side of the radiator, as the original fan, located on the engine bay side of the radiator, would no longer fit due to the position of the turbo. Note the tight fit between the turbo and radiator and also the distributor and manifold.

Whilst I was playing under-bonnet games, Paul set to work on the piping. First was the dump - a difficult task given the large 3" piping and the lack of space between the turbo exhaust housing, the air con compressor and the radiator. The result is very impressive. The intercooler piping came next - thankfully this was relatively simple, due to the mounting position of the 'cooler just off to the side of the engine bay and under the bonnet vent. This location was decided on due to the ease of piping and the short length required. With an air feed from under the bumper, a small fan mounted beneath it (from a motorbike) and a vent above to draw the air through, it should get a resonable amount of airflow. Having said that, I will still most likely front-mount it sometime in the future (I just don't want to lose my aircon!). We also plumbed in a Turbosmart Type I blow-off valve in the inlet plumbing just before the throttle-body.

I bolted the intercooler into place using a few mounts made up from off-cuts of aluminium, and with all the piping sorted, clamped it all together with some nice silicon hose. The K&N air filter was simply clamped onto the inlet of the turbo for now - it will be relocated somewhere cooler later on, with some new 3" piping.

Thursday was the day the car was booked in to the local exhaust shop. The driveshafts were put into place and the wheels bolted back on, then the car was lowered to the ground and rolled outside where it was loaded onto a tow truck and taken down to the exhaust shop. Friday afternoon the car returned with it's new system, including a high-flow cat, 3" muffler and flex pipe and 3" piping all the way through. Some may consider 3" piping on a 1.6ltr engine an overkill, but 2.5" is too small for this application and 2.75" is too expensive as it is not a common size. The 3" piping also gives more potential for future modifications, and as I have found it since it is not overly loud or droning.

*** UNDER CONSTRUCTION - THE REST OF THIS ARTICLE IS COMING VERY SOON! ***

Current pricing breakdown:

The third article will detail the engine installation and tuning and the results achieved.

Compiled 14/10/01 by Steve - steve@turbocorolla.com
Photos by Shane - shane@4agze.com