20V Quads on modified 16V Bigport > Ignition > Dizzy-to- CAS conversion

[GeeEss]

Sleepless in Sydney (again). . .

I am looking at DLI for my Quads on Bigport conversion.

I want to keep the original Bigport Dizzy intact in case I need it later so am looking around for another to use as a CAS.

1. Can 86kW Dizzy be converted to a CAS (Adaptronic ECU) or do I need to source either a 4AGE / 4AGZE type?

If YES what mods do I need to make and how? i.e. if I have to grind off 3 of 4 rotors how accurate does metal removal have to be WRT balance of dizzy? Is it necessary to cut down shaft to base of rotor?

1b. Further to the above; can an early (Cap+Rotor) 4AGZE distributor be converted to a CAS by above method?

1c. Has anyone used internal 4AGE Dizzy Dust Cover (19121‑16160) and siliconed that in place as a Dust Cover?

2. I have ordered a rebuild kit from KBOX & spiral gear, but mechanical parts aside whatever Dizzy I get is still 20+ yrs old; what are the chances I will have issues with the transistors and if so; can u buy them and how much are they from Denso?

3. Re. attached pictures; Can s/one confirm if Dizzy in 1st picture has had 3/4 rotors removed and why it only has 4 teeth Vs 24 on the 100kW unit?

4. Is the original ignitor still used or removed / replaced in COP Ignition?

[knightrous]

1. Can 86kW Dizzy be converted to a CAS (Adaptronic ECU) or do I need to source either a 4AGE / 4AGZE type?

It can be, I've used it with my megasquirt driving the stock igniter and single coil setup. However, if your going for sequential fuel or spark, it just doesn't have enough teeth to provide decent resolution. The 24 tooth dizzy from a smallport is better.

3. Re. attached pictures; Can s/one confirm if Dizzy in 1st picture has had 3/4 rotors removed and why it only has 4 teeth Vs 24 on the 100kW unit?

No, none of the teeth have been removed on the first dizzy. That is just the stock bigport dizzy, it has two pick wheels in it, a 4 tooth NE wheels and a 1 tooth G wheel. The NE wheel is used for working out the position of the crank and the G wheel is a home signal to let the ECU know when it gets to Cyl#1 TDC. You'll notice the small port 24 wheel is similar, it has a 24 tooth NE wheel and a 1 tooth G wheel.

4. Is the original ignitor still used or removed / replaced in COP Ignition?

It it removed. However, with the stock 4AGE 4 tooth dizzy, the igniter is a apart of the Toyota VAST system, and the igniter actually connects to the dizzy and the coil. It provides an nice square wave out pulse tach signal which you can feed to the ECU. Infact, the VAST type igniter doesn't even need an ECU to make the ignition system work, you can crank the motor over with the ecu unplugged and spray fuel in the intake (start ya bastard spray) and it will run. So you could keep the stock igniter (with the coil unplugged) purely for the fact it gives you a nice tach signal to connect to your aftermarket ecu.

Most COP's like the 1NZFE or 1ZZFE COP's have internal igniters in them and are triggered with 5v signals. If you use COP's that don't have the internal igniter (1MZFE), you with need external igniters to run them.

Next month, I'm actually going to be doing a MegaSquirt 2 install on a mates AW11 which has a 4AGE with bigport head, small port block, 288 cams and AE111 quads on it. We will be using the stock bigport dizzy, coil and igniter and running batch fired fuel and stock single coil ignition. Eventually we will source a small port 24 tooth dizzy and upgrade it to full sequential fuel and install some COP's for sequential spark as well.

[GeeEss]

Many thanks; that helped me a lot but I have never come across a Dizzy with internals like either of those cars in the photos.

My Dizzy internals < see photo> are identical to those in a 6/1991 ADM 100 kW SX Hatch I had a few years ago; in that they have a 24 tooth NE wheel and a 4 tooth G wheel.

I looked up my car (JDM 1988 AE92 FXGT) in ToyoDIY and the Dizzy part number (19100-16160) is correct; and was used in various AE9X chassis until 7/1991 so that would seem to make sense.

Is it a late big/smallport hybrid or something and more importantly, does this mean I can use it* as a CAS by just removing CAP+Rotor and fabricating a Cover, or would I have to grind off 3 of the 4 teeth on the G wheel??

Any ideas?

[GeeEss]

For the reference of anyone interested; Anthony from Kaizen Garage responded @ follows;

Thats just a normal big port dizzy. You cant run it as a full cycle cas as there is no cam reset. To have a cam or crank reset. The maximum number of teeth you can have for those resets is 2, preferably 1. SO yes you would have to grind off 3 of the teeth from the 4 tooth wheel (the 4 tooth wheel is called a period reset, meaning the ECU knows the next cylinder period is about to start, it just can’t tell which cylinder that is).

1st picture is of an AFM MR2 distributor.