Vacuum takeoff on Edelbrock Triple Manifold

[macdonge]

Looking for advice... I bought a triple carb Edelbrock manifold for my '39 Merc block but there is no takeoff (tapped hole) for the vacuum source I'll need for the crab distributor I plan to use. The Edelbrock website's picture of this part depicts two such holes (on the front and rear carb positions) but mine has nothing. If I drill and tap my own takeoff, wouldn't it make sense to put it adjacent to the middle (or 'primary') carb? Anyone else encountered this? Thanks

 

[scicala]

Whether the port for manifold vacuum is by the front, center or rear carb, it shouldn't make a difference. It's all the same manifold vacuum.


Sal

 

[51 MERC-CT]

Ran across one some time back that someone did sort of a belt and suspenders installation on, sort of like this.

 

[Ritzy1]

I believe Jim Linder (Bubba's) told me the vacuum advance wouldn't work with multiple carbs, so I put a plug in the front cover where the original line came out. Because I was going with power disc brakes though, I had my machine shop drill and tap a hole in the manifold to supply vacuum to the booster. Edelbrock suggested the hole be centered on my intake.

 

[34PKUP]

I believe Jim Linder (Bubba's) told me the vacuum advance wouldn't work with multiple carbs, so I put a plug in the front cover where the original line came out. Because I was going with power disc brakes though, I had my machine shop drill and tap a hole in the manifold to supply vacuum to the booster. Edelbrock suggested the hole be centered on my intake.

Just wondering what 'multiple' carburetors/or carburetor you are using on the manifold you show?

 

[Frank Miller]

I believe Jim Linder (Bubba's) told me the vacuum advance wouldn't work with multiple carbs, so I put a plug in the front cover where the original line came out. Because I was going with power disc brakes though, I had my machine shop drill and tap a hole in the manifold to supply vacuum to the booster. Edelbrock suggested the hole be centered on my intake.

I beleve this to be true for the loadamatic distributors but the earlier ones just used manifold, not ported vacuum.

 

[Ol' Ron]

I made three 1" spacers under the carbs to make the progressive throttle linkage easier to operate. In each spacer I put a vacuum port the front one is for the PVC valve the center is for the distributor and the last one is for the windshield wipers. The vacuum advance works just fine.

 

[Ritzy1]

Just wondering what 'multiple' carburetors/or carburetor you are using on the manifold you show?

That's the base of an Edelbrock Slingshot. Using twin Stromberg 97s.

 

[macdonge]

Ol' Ron... I like your idea. I will be using progressive linkage and was worried that, depending on where I put the port(s), the fitting (or associated hose/tubing) might interfere with it.

 

[scicala]

I believe Jim Linder (Bubba's) told me the vacuum advance wouldn't work with multiple carbs, so I put a plug in the front cover where the original line came out. Because I was going with power disc brakes though, I had my machine shop drill and tap a hole in the manifold to supply vacuum to the booster. Edelbrock suggested the hole be centered on my intake.

The vacuum to the distributor brake will be different when using Holley 94 type carbs setup for Loadomatic (venturi suction/ported vacuum), plus there is no vacuum supplied at idle.
Taking vacuum from the manifold for the brake should work with multiple carbs.


Sal

 

[macdonge]

I agree Scicala. Thanks for everyone's input! I plan to drill & tap one port which will tee off to the Crab's brake and a vacuum gauge.