Hei vacuum advance hookup

hei vacuum advance hookup

Do you plug your vacuum for HEI distributors?

Discussion in High Performance Modifications started by mike shull, Oct 10, 2009 . Hello everyone, I have a HEI distributor with the vacuum advance, 454 motor, and a 750holley carb. Was talking to a Summit sales guy and he said most guys plug their vacuum for their distributors.

Why should I retain the vacuum advance on my distributor?

So there are significant advantages to retaining the vacuum advance on your distributor. In the case of the HEI, you can actually purchase an adjustable vacuum advance canister that will allow you to custom-tune the amount of timing advance.

How much vacuum advance can you add to a manifold?

Each clockwise turn of the Allen wrench will add about 1.5 degrees of additional advance above 5 to 7 inches of manifold vacuum. The maximum is about 14 degrees of vacuum advance. If too much advance is added, the engine will either start to knock or ping or perhaps it may surge slightly at very light throttle opening with high vacuum.

Does vacuum advance produce advance at idle?

I know that hooking up the vacuum advance to manifold vacuum will produce advance whenever there is a vacuum in the manifold, such as at idle, cruise, and light throttle, and will produce no vacuum at WOT.

What is the vacuum advance on a HEI distributor?

The vacuum advancement on HEI distributors (high engine ignition) is one of the first and most important changes for optimizing engine performance. So, how do you change the HEI distributor’s vacuum advance?

How does the HEI advance the spark plug?

The HEI also has two methods for advancing the spark. It has a vacuum advance that operates the base plate of the distributor. The distributor is in a semi-retarded position when the engine is starting. Once started, the vacuum produced turns the base plate and increases the advance for the spark.

Where can I buy a HEI distributor?

The HEI distributor can be purchased at any auto parts store and comes with three different spring tensions, from light to heavy. The advance curve can be changed with the springs. Don Bowman has been writing for various websites and several online magazines since 2008.

Can You widen the plug gap on a HEI distributor?

Tip: When you have installed your HEI distributor, its best to widen the plug gap as well. Tip: You should run a new power wire that is getting a full 12 volts. Simply splicing into the existing lead is not getting maximum power to the ignition, as that is a resistance wire.

Discussion in Engine Topic started by mrluckies, Jul 7, 2007 . Ported or Manifold Vacuum for Vacuum Advance? The Cliff Notes are: Try and use full time manifold vacuum for you vac advance on the distributor first. It will give you a smoother idle with lower throttle blade setting.

What is the maximum amount of vacuum advance on a motor?

Can you run too much vacuum advance at idle?

One problem with running too much vacuum advance (hes talking 24 degs in the vacuum can) at idle is when you hit your total mechanical advance at cruise it will be 62 degs btdc (38 degs total without vacuum as stated). Its one thing to run 20+ degrees initial with say 10 or so degs vacuum for a total of 30 - 32 degs initial and 36 total at WOT.

How many degrees of advance at idle?

If you hook your vacuum advance up to a manifold source then you will have 22 degrees total advance at idle and some portion thereof at cruising speed depending on engine load. If you hook your advance up to a ported source you will have 12 degrees at idle and 22 degrees when there is sufficient ported vacuum to give you all of your advance.

When do you add vacuum advance to a ported advance?

With ported advance, vacuum is applied once the throttle is opened past curb idle. Some tuners prefer to add vacuum advance at curb idle on engines with big camshafts to improve idle quality. If you choose to do this, be sure to remove the vacuum advance line from the vacuum source before checking initial timing.

What is the difference between mechanical advance and vacuum advance?

As an example, 10 degrees of initial and 24 degrees of mechanical advance creates 34 degrees BTDC of total timing. Vacuum advance is a separate system that uses a small diaphragm assembly attached to the side of the distributor.

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