Distributor Vacuum

[Guest alexpink]

I'm running twin 40s on a 2.0 pinto with a brake servo and distributor. I understand that I need to connect the servo vacuum to the inlet manifold, but what do I do with the distributor vacuum connections?

[richardm6994]

For the vac on your dizzy to work correctly, you'll need a vac take off on all 4 inlets and connect them together to a small plenum and then take your dizzy vac from them plenum.

If you don't do this, the vac advance on your dizzy will be erratic / pulse.

[IanS]

Distributor vacuum is there as a fuel economy measure.

How many miles are you going to be doing at cruise?

If the answer is low then just do not connect.

Through a plenum half works as the max vacuum does not get generated better than nothing for MPG but could be improved by a mapped ignition.

[Guest Gargoil]

Just a question, would Alex need a vac if the dizzy had electronic ignition?

[IanS]

If it is a mapped system then no but distributor would probably need to have all its advance locked.

If it is the contactless system with a seperate amplifier then it is no different than a contact system as advance is provided in the distributor.