Hot Rods Does Ford 94 carb have vacuum ports?

I'm running two Ford 94 (Holly) 2 bbl carbs on my '50 Merc. I'm thinking about swapping my mallory dual point dizzy for a Pertronix. The Pertronix has a vacuum advance cannister, but I can't find a vacuum tap on either of my carbs.
Anybody run into this situation?
Thanks,
Matt

 

Classically, no.

You would need to drill and tap the manifold, or install spacers with ports.

Spacers are easiest, fairly cheap, and easy to install. They run about $40 each, less longer studs and gaskets.

You would need two, so as to not disturb the geometry of the throttle linkage.

 

There isn't anywhere on the intake where you could tap in for vacuum? On my Offenhauser 3 x 2 setup there is a small hole that could be used for vacuum. You can see it under the back carb in this pic.

 

My buddy ran into this problem and if I remember right he got some Y Block carbs?I think they were EBU's and had the vacuum port.

 

I've seen 94s with a vacuum port on the back. Not sure what vintage.

 

Do not use that port for vacuum for anything but a stock Ford "Load-A-Matic" distributor. It has a weird venturi vacuum signal that won't work right for a regular vacuum advance. You need full manifold vacuum for those. @GordonC shows a good example.

 

Again, you folks are a goldmine of info! Thanks again!

 

Does your pertronix want ported or manifold vacuum, or does it not matter ?

 

The later 94s had a port.

 

Reading this brought up something that I was going to try years ago and never got around to. The 8BA and late 94 carbs did have a vacuum port but as tubman pointed out it provides a weird venturi vacuum signal for the old Loadamatic distributors. However, it's actually a combination of venturi and ported manifold vacuum. Pull one apart and you'll find a passage that runs from the vacuum port down to a port in the throttle body that I believe is located just above the throttle butterfly when closed. I've always wondered if you could block the upper passage from the vacuum port to the venturi ports and then just use the remaining ported manifold vacuum for a modern distributor.


Just a thought... and if I remember to I'll pull one apart when I'm back at the shop next week and take a look.

 

from my understanding, ported and manifold vacuum is different, - not sure what you mean by “ported ported manifold vacuum “

anyway, this may or may not be of interest to you …….
https://www.eatonbalancing.com/2010...-barrel-for-late-model-distributors/#more-164
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Yes you can, and it is fairly easy. Somewhere not long ago there was a post about doing it and it was just what you would think. Take it apart, plug one passage and you're good. Also I think they suggested to drilling out the other passage because it was so small.
I would say do some searches for it but I can never find what I'm looking for by searching.

 

Yeah, I didn't explain that too well. First of all I added an extra "ported" in the sentence... fixed that. However, while we think of ported and manifold vacuum as being different, in reality once the throttle blades open past the port they'll both read the same.. just semantics I guess.

 

How a spark is made and how it is timed are two very different things. Whether to use ported or manifold vacuum is more a function of the springs and/or weights in the distributor and whether the goal is oriented more towards performance, fuel economy, or emissions.

 

Now that I swapped the leaking 7.5 Hg PVs for 3.5s, my '50 Merc (dual carbs, Mallory dual point diz) car is running better. Someone installed a cam with a bit of a lope, which I'm not real fond of. Any tips to get the best low to mid-range performance? Should I check the advance springs? Are they color coded?