Giving Up On Vacuum Advance Options

[Ansbacher]

Car = '74 2.0 Liter, Dual Dellorto Carbs

For years I have been 'adequately" running an 009 mechanical only distributor. Finally took the pervasive advice out there to go with a vacuum advance dizzy from a 1.8L 914. Since only one of my Dellorto carbs had an existing vacuum port (ported type), I had to drill a port in my other one (no problem there). I used good quality anti-pulse valves in the lines and measured a maximum vacuum of 12 inches of mercury with partial throttle.

Installed the 1.8 dizzy and set the timing, first without the vacuum lines attached. To satisfy my usual 30-32 degrees at 3500 RPM, the idle timing had to be at about 5-6 degrees (quite low for my setup which is happier at about 10 degrees. When I attached the vacuum lines my timing at 3500 RPM went sky high into the 40s. This seems way too high. Is this normal? Overall, I found the car to run better without the vacuum attached and the carbs plugged off.

Am I doing something wrong here? I don't like the numbers I am getting. Everyone said this was the way to go with carbs, but I am not seeing results. Advice appreciated.

Ansbacher

[BK911]

I've been running an 009 with carbs on a 1.7 for over 10 years now.
Car runs awesome.
If it ain't broke..........

[Rand]

I've been running an 009 with carbs on a 1.7 for over 10 years now.
Car runs awesome.
If it ain't broke..........

I love that yours runs awesome. But can you imagine a tuning that would bring another 20hp with the same mileage? I bet Joe Sharp could.

Back on topic, should he use vacuum advance or retard? I found it to be differential because of difference years, dizzyy's, etc.

I had one experience where the retard wasn't working and it made my idle high. Fixed with a part replacement. Carbs will be always suck when you get out of your optimum altitude. FI adjusts as needed. Is there really a need to keep debating it?

.

[72hardtop]

I've been running an 009 with carbs on a 1.7 for over 10 years now.
Car runs awesome.
If it ain't broke..........

I love that yours runs awesome. But can you imagine a tuning that would bring another 20hp with the same mileage? I bet Joe Sharp could.

Back on topic, should he use vacuum advance or retard? I found it to be differential because of difference years, dizzyy's, etc.

I had one experience where the retard wasn't working and it made my idle high. Fixed with a part replacement. Carbs will be always suck when you get out of your optimum altitude. FI adjusts as needed. Is there really a need to keep debating it?

.

Not a debate with an EFI system. But unless one is traveling between altitudes on a regular basis (most aren't). I prefer a dual set up. More horsepower. If one is going EFI go with a modern set up not the stock one.