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Project Gunieapig...

Posted: Wed Jul 20, 2005 7:14 pm
by nicke
I know this is not for a transaxle car... But it is an Alfa. I just got throttle bodies and a GoTech computer for a '69 105.

So far all is well (the engine is still beeing built so this is all hypotetical) but the Dizzy seem to be the biggest puzzle...

1. The L-Jet Dizzy for the 6cyl cars is apperantly all working well with the GoTech ECU.

2. The L-Jet Dizzy for the 4cyl cars (here in the US, Spiders) are from what I understand no good... Last night I looked at a wiring diagram for 4cyl L-Jet and there are 2 wires coming out of that Dizzy one for the Tach and one for the ECU, but the TDC and or Revs is suposedly coming out of the crank sensor... I'm confused. There's some kind of magnetic thingamabob... I'll borrow a Spider dizzy tomorrow and do some more research...

3. The L-Jet for Fiat Spyders take RPM and TDC from the Dizzy... More confusion.

4. As it seems the best solution for the Dizzy/GoTech interface seem to be someting with a Hall Sensor. My current plan is to Frankenstein the guts of a Golf dizzy with a Hall Sensor with a 80's Spider dizzy. Anoyone have any other brilliant ideas. Any help is welcome!

5. I really don't feel like putting a late model 2L fly wheel on my '69 1750, and I could always add a 164 sensor on the old flywheel, or rig something on the harmonic balancer in the front, but the Dizzy seem like a more elegant solution, especially as I just sent out the Crank, Rods and pistons to be balanced...

This is too much fun!

Cheers, Nick

Posted: Thu Jul 21, 2005 10:31 am
by 4agedub
Ok I see that you're going to run with the std Gotech MFI v4.

You need a distributor with a 6 blade chopper plate (6 triggers per 360') then it should be good.

Please do check the rotor phasing as explained here

http://www.gotech.co.za/support%20rotorphasing.htm

Posted: Thu Jul 21, 2005 10:57 am
by nicke
I found an Alfa Dizzy that will work. The 80-81 Spider L-Jet has a hall sensor. But I have no idea what the output pins are. Anyone have a diagram? I need pin-out info on the white cable going out of the distributor, it's about 6ft long and ends in a black terminator.

Posted: Thu Jul 21, 2005 2:32 pm
by Andrew.b
Hi,

Would you not need a 4 blade chopper plate for a 4 cylinder Alfa engine?

I think you need a dizzy from a '88-91, 1.8 ALFA 75 injection.

They ran with bosch motronic injection, and the dizzy would be perfect.

hope this helps

Found a Dizzy

Posted: Thu Jul 21, 2005 6:30 pm
by nicke
The 80-81 L-Jet Spider dizzy's have Hall sensors! And I found one. Spent the evening rebuilding it, I also found a brand new Hall sensor from a Fiat 132 that fits right in. No vacum advance, no extra magnets, it's all good. It has 4 blades and should work fine. The ignition for those Spiders also have a coil sitting in a HUGE heat sink with an ignition module under the coil, I kinda like the idea of not running the ignition pulse straight trough the ECU, now I have to figure out what nice coil will work with that setup.

Cheers, Nick

Posted: Thu Jul 21, 2005 10:14 pm
by 4agedub
On a four cylinder you want a four blade chopper.

The sensor in the dissy posted last allmost looks like a magnetic type pickup. These should be ok as well if it generates enough volts.

Posted: Fri Jul 22, 2005 12:17 am
by Mats
Andrew: Have you verified this? My 75 TS motronic distributors are all very empty as they have the 60-2 on the crank.
Bummer for me. :/

Posted: Fri Jul 22, 2005 3:23 am
by 4agedub
With the 60-2 wheel at the bottom you can go for the Gotech MFI Pro ecu and just use the distributor to distribute the spark. :wink:

Posted: Fri Jul 22, 2005 4:28 am
by Mats
Yes, of course, If I used the TS engine. But this was a question about the dizzy. ;)

Posted: Fri Jul 22, 2005 5:15 am
by 4agedub
Whell you can always modify the distributor. ?

Posted: Fri Jul 22, 2005 11:59 am
by Mats
That is what I will do id I cant find an OEM solution.

Nice blister on my hand...

Posted: Fri Sep 02, 2005 6:37 pm
by nicke
I've spent most of the day porting and polishing a 40mm, 1600 Weber manifold to fit my rather obscene 45mm throttle-bodies... The original 38mm spica manifolds are a bit small in comparison... The only odd thing is the odd off-center match of the 45mm rubber spacers (that I'm way lucky to have found), 1mm on top and 4mm or so at the bottom... See the pic at the bottom.

Tomorrow I'm planning to match the manifold to the head and do some light polishing. I'm not going too crazy on the head as US pump gas is not too exciting and I'm planning to run old school 1600 GTA cams with OK lift and SILLY long duration... I want to have some low-end torque left... The funny thing witth the 1600 manifold is that he bottom heavy offset carries on to the head... TPS and MAP mix will be interesting with that long overlap.

I'm also using 10:5:1 J&E pistons, over-sized liners and a polished/knifed crank...

This engine should be interesting to map, and it'll be my first one... hence Project Gunnieapig...


Cheers, Nick