After an interesting experiment with the 3TC, and much discussion.... another motor needed to be chosen. The next on the list for a small, late model, toyota NA motor was the 3S-GE. A Generation 2 motor out of a Corona was chosen, and all the necessary bits were sourced. What follows are details of the conversion, thanks to Mark, Matt, Tim, Lance & Reo from Garage Dori team, Brendan from Niteparts, Stu, and Aiden from Drive Inn, Carl & Dan from Appco, Scott & Neil at Fraser Cars

Last update: 18/01/2005

Sourcing Parts:

Purchased a 3S-GE complete from Alan in Wellington. Apparently low 100,000km's and a good runner. He took my 3TC motor away which was useful.
Bought a bellhousing to match the block to W55 gearbox off Mark, sent it to Frasers to be skimmed up.
Bought a GEN2 carb manifold, unfinished off Fraser Cars too.
My old Redtop 4AGE that we put in Keiths car after Round 4, was swapped for 2T alternator and 20V quads at the time. The quads became useful for this conversion.
1G Starter motor from the 3T conversion was used.
Still had Megasquirt Ecu which would do fuelling. Std 3S ecu for ignition.
Extractors to be made by Lance
Driveshaft to be cut down by Aiden at Drive Inn
Clutch was the same from 3T Conversion

Fitting the Motor:

With all motors that we fit, I like to fit new seals were possible. So new cam seals and rear main were fitted. The motor was then given a good wash with kero.
The old 3T was pulled out, and then the 3S lowered in place with a crane. It was not going to sit in there nicely, but too far forward. So, the firewall had to be given a beat with a 10lb sledge. It was knocked back about 2-3 inches to clear the standard distributor cap and water outlets.

With the engine able to hang in a suitable spot, it was yanked out and the clutch & flywheel fitted. Then, the gearbox was bolted on and the motor was lowered back into the bay.
The gearbox mount bolted onto the front 4 bolts, as per the 4AGE install. The 3T and box bolted to the rear 4 bolts, as per 3A Auto I believe.
Brendan lined up the motor and propped it up so it was stable, then helped with making cardboard cutouts of the new mounts. With the cutouts marked up on some steel Lance gas-axed them out, and then I cleaned them up.
Test fitting the cutouts on the motor required them to be drilled and one side bolted to the block, with the other side bolted to the chassis mount. Final positions for the mounts were decided and they were tacked up in the engine bay. Brendans work again.
Back to Lance's work to weld them up, then a bit of a clean and the most horrible job (IMHO) was done. The motor sat pretty well.

Then, a suitable driveshaft was found to be cut down by Aiden from Drive Inn. The usual fast turn around and great deal ensured this part was painless. The set-up was starting to look good.

Making the Intake Manifold:

There was no way I was going to try and use the standard manifold, it was ugly, bulky, and for the hassle it seemed better to just fit quad throttles from a 20V Silvertop 4AGE.
With the Weber carburretor manifold from Fraser Cars, I chopped the edge of the weber bolt flange off, and Stu welded on the 20V flange supplied by Brendan. 1+2 and 3+4 ports could be roughly located together, with the center gap bigger then normal.
Then, with Lances help, the 20V face and manifold face were drilled. Then the ITB's were lined up again and their bolt holes marked, to be drilled and tapped. Once done, with the quads bolted on, the linkages needed to be extended. Once again, Lance on the welder with some steel tabs.
Lastly, we drilled and tapped the ports to run a brake booster, fuel pressure regulator, and MAP feed for MegaSquirt.
With the manifold bolted on, with the quads, there's only just room for 70mm trumpets if the brake fluid splitter is moved.

Wiring & Tuning:

The standard ecu was retained for spark only, with the water and air temp sensors faked with resistors. The map sensor is plugged in but is open all the time, injectors not in use of course. Spark is currently set around 20-25 base with max advance about 35, but under load only 25deg. I can't get any more advance on it due to the bolts in the distributor housing. In hindsight, The standard ECU may have required the knock sensor to be plugged in for it to run more timing at higher rpms.
Initially, 2 cyls were used for map for MS, and 2 for the fpr. However, it bumps around a lot like that, so I've added a standard Toyota dampener in and now all 4 are used for the MS. Idle is about 69-70KPA.
Hindsight again, the manifold wasn't completely flush with the head and was leaking a little on #4. With the manifold cleaned up, idle dropped to 50kpa, which is comparable with 4age ITB's and other ITB installs.
It's running really well and I'm getting about 150kms for 17ltrs. Plenty of room for improvement.
The MS is loaded up with the EXTRA code now, which contains 12x12 tables, and all sorts of other goodies which I'm unlikely to use. It's heavily biased between 100 and 90, in 2KPA increments.
I'm using a 4AGE oil pressure sender, but as it's in the back of the head instead of the block its reading is pretty different to a 4age. about 1/3 instead of 2/3, and it drops away when it gets hot.
Man the wiring is messy here, I should have really tidied it up. And the nonstandard megasquirt case is not pretty. Oh well.

Other bits and pieces:

Lance made up some 4->1 extractors out of 45mm pipe, and it joins up with the rest of the 2.5" exhaust (from turbo days).
Theres water running around the block for the thermostat bypass and oil cooling, however all this has been removed and it just runs no thermostat.
The first motor ran a bearing on the track: Because, on the way to the track, as the oil filter bolt was shortened, but it wasn't square, so the oil filter seal crapped out at high revs and dropped all the oil. After fixing this and putting some oil in it, the motor was slow and quickly ran a bearing.
So, another motor was sourced from Dan this time, and it's in great condition... 109kW at the wheels on the Torque Performance dyno.
It's a bit like having a turbo for the first time.... I only drove the last one around the track for one lap, as I was tuning whilst Brendan drove it on the way down. So it had been a few months with no driving. However, I started using it daily for a month and put 2000kms on this setup.

As usual, hit me up on the forum if you've got any questions.

Old Megasquirt Config - 3SGE-Gen2-ITB MSnS-EXTRA 020i

However, I recommend using the following Fuel Table (VEX format) and using the latest MSnS-Extra code.
3SGE Gen2 ITB Fuel Table