Home Built Z 'Full video build'

[Home Built by Jeff]

59 minutes ago, 240260280 said:

Some guys in your country did a lot of dyno pulls to compare carbs to EFI and also advance on a 510. The results were not significantly different.... either this is the finding or they did not test properly.

 

Outright power would generally be the same between well tuned carbies and EFI, but EFI can be tuned throughout the rev range so you can have better driveability cold starts, etc. 

The issue with my car though is the lack of vacuum advance so any dizzy would have to be set on a compromise static timing. 

[tzagi1]

Jeff, the vac advance problem is easily solved, You can take manifold vacuum and run it via a solenoid controlled by a micro switch on the throttle, what you are looking for is to cut off the vacuum at idle.  it will simulate ported vacuum just fine. been there, done that, worn off the t shirt.

[240260280]

The problem I noticed with a triple carbed L engine and timing is:

• Z's like a lot of timing at idle (20 to 25) but not when starting (kick back)... 5 to 10 is nice when cranking
• A lot of timing at idle is not great for emissions (lean, slow burn likes lots of advance)
• too much early timing will ping fast on acceleration
• ~34 to 38 seems to be best range for L heads at max advance under load.... depends on chamber, cam, and compression

Without vacuum advance, setting a 280zx distributor at ~ 18 initial and ~35 at final is an ok compromise... no advance for lean cruise is sad

 

One idea I have not tried yet is to connect the choke cable where the vacuum advance connects. The cable could be pushed in to reduce the crank advance, then pulled back when running.

Edited March 20, 2019 by 240260280

[Home Built by Jeff]

I was under the impression it was more linear, rather than on/off? 

Either way, the 123 system I believe has a range of advance maps that can be tuned via Bluetooth so it can sort out all of that without worry about vacuum for a signal. 

[Mark Maras]

 

 

 

5 minutes ago, 240260280 said:

 

 

One idea I have not tried yet is to connect the choke cable where the vacuum advance connects. The cable could be pushed in to reduce the crank advance, then pulled back when running.

 It will work just fine. Ford Model A's (and others) had a lever on either side of the steering wheel. One for ignition timing, the other was a throttle. Are you going to mount it next to the choke?

[Captain Obvious]

4 hours ago, Home Built by Jeff said:

I have done some more tracing of wires and it looks like there is a faulty ignition switch which is not sending out the power to the green/(white I think it is) which is why there is no power going in to my tacho.

Cool. Glad you got to the bottom of that and glad it was that simple.

I've been inside of multiple ignition switches to date, and I believe it is time for everyone to replace their switches because they all look like this inside:

[Home Built by Jeff]

Just now, Captain Obvious said:

Cool. Glad you got to the bottom of that and glad it was that simple.

I've been inside of multiple ignition switches to date, and I believe it is time for everyone to replace their switches because they all look like this inside:

I pulled the part out but I didn’t spilt it. Does the black section just clip in?

[Captain Obvious]

No, there's a rolled over metal beaded edge. I chucked it up in a lathe and cut the bead off just as exploratory surgery.

Sorry if I gave you any false hope. It's an autopsy.

[rcb280z]

5 minutes ago, Captain Obvious said:

I believe it is time for everyone to replace their switches

Yep, that's exactly why I replaced mine a year ago.

[240260280]

It is linear but over a very short range.

 

606-52 "Euro" distributor mechanical  ~12degrees is all in at 1000rpm

 

 

D6K8 280zx distributor mechanical  ~17degrees is all in at 1250rpm

[Home Built by Jeff]

I finally get it started!!! Wooo Hooo!. I had to cobble some bits together, but it starts and runs!

 

 

[240260280]

Well now you have unleashed the meanest, baddest, fastest beast in your herd.... and it will put a smile on your face once you get it on the road. 

Most notably, after you drive a z for a few hours then pop into another car, you immediately miss the torque.

 

Congratulations!!!