How do you connect Vacuum Advance with triple Dellortos?

[warrenz]

Hello to all you people running triple Dellorto carbies.

 

Getting close to putting the triples on the 240, linkage kit and trumpets arrived today and part way through putting a rebuild kit through all 3 carbies. I am confused with how to connect the vacuum advance from the distributor. Des Hammill's book does not mention it.

 

The Dellorto has a vacuum port on it, but from what I have read with 1 choke per cylinder this vacuum pulses, I assume it is used to tune the carby with a vacuum gauge. But if the vacuum line is connected to the manifold then the vacuum is constant so not good at idle. My Cannon manifold does not have a port for the distributor vacuum line so would have to be drilled and tapped.

 

I am running the standard distributor with a Pertronix electronic ignition.

 

What do you guys do, a picture would be nice.

 

Cheers

Warren

[Toecutter]

Hi Warren,

 

I drilled and tapped the redline manifold at the front. I'm pretty sure that the vacuum created when at idle is so low it will not effect your timing advance but when you give it a rev obviously the carbs pull air through pretty hard and there's the advance when you need it at revs.

 

I've seen a few that have the balancing tube that runs along the top and assume it would provide more vacuum for brake booster!

 

I'm happy with how mine is pulling through the rev range. You can check it out this coming weekend if you like.

 

Sulio

[Glen]

If your running tripples i wouldnt have thought fuel economy would be a priorty. I know the name does suggest that it advances the timming which it does but only when cruising on a freeway. If you dropped off the vacum line while doing a qtr mile run it would make absoulity no difference in performance.

hope this helps

 

Edit: spelling

[gav240z]

If your running tripples i wouldnt have thought fuel economy would'nt be a priorty. I know the name does suggest that it advances the timming which it does but only when cruising on a freeway. If you dropped off the vacum line while doing a qtr mile run it would make absoulity no difference in performance.

hope this helps

 

Good point, I would suggest dropping the vacuum advance and getting the distributor regraphed to suit your camshaft profile. If budget permits, otherwise I guess try Sulio's method.

 

FWIW I don't run a vacuum advance on my Z only mechanical advance.