Any of you guys using this intake with 4 97s and are running vac advance on their setup? If so, how did ya'all go about it ? If its all too much of a PITA, I may go with mech advance. Thanx in advance Rat
Just plug it into the port for the factory wipers (if it has one) It's pretty simple to drill and tap a port. The vacuum advance only moves a diaphragm a little bit and it is not a vacuum leak unless it's broken so it can be plugged in anywhere in the intake. I'm not racing anybody and I can use all the extra gas mileage that it brings. I have cleaned this up some since I bought it but you can see it here.
Hehe...sure FO. I can use mechanical, all my other rides do but they're set up for more go so economy is'nt an issue. Just picking up vacuum from an intake runner isn't the correct way to do it is it ? Or is that sufficient/the right way to do it? School me...... Rat
Go over to the Ford Barn and check out Walt Dupont's thread-he's running 4 twos on the street and getting great gas mileage.
Sorry I should have realized that you were talking about a flat head. No the flathead distributor uses a completely different system. I just used an old original Mallory with only the centrifugal advance on my old Merc flathead.
Sorry again I'm not to good on codes I was thinking it might be an overhead. If it is a SBC then the vacuum advance goes to the intake manifold as I said first. The factory vac adv plugged into the side of the carb on most applications but that port went straight down under the butterflies.... to manifold vacuum. The distributor above on my Stude motor is a Delco unit. When I first got the truck it would fall on it's face when I nailed it from a light. I finally figured out that the points plate was rewired with a heavy gauge wire by the PO. When I nailed it the timing retarded as it was supposed to do and disconnected the points. when the vacuum came back and advanced the plate the wire made contact again. It always looked OK when I pulled the cap. A nice flexible wire cured all of my ills once I looked close enough.
Some manifolds don't have enough space behind the rear carb to run a large diameter distributor with vacuum advance. You can run an earlier ('55-'61) factory Chevrolet "snap cap" iron bodied distributor, or an aftermarket small diameter bodied distributor in either case. If there's plenty of room, this is all a moot point. Many street engine builders will go full mechanical advance distributor when they have installed a large camshaft, which has a very low vacuum signal, or when you have a large carb, or multiple carbs set-up opening non-progressive, all instances where the vacuum signal is very low or erratic. The Factorys all knew this, when they built a "power-pack" engine or during the "muscle car" era, certain cars had more camshaft timing and more carburetion, so they offered these engines with distributors having mechanical advance solely and eliminating the vacuum advance. I think, in any case, if you are going to run a vacuum advance, I would strive to pull vacuum from the strongest and most stable source. Tapping into just one leg of a V-8s intake manifold would mostly give you that cylinder's vacuum signal, for the most part, and it may even "pulse" as that intake valve opens and closes. I would tap into a plenum area somewhere near the manifold's center, where the vacuum would be most uniform and even from all cylinders, rather than from a carb or runner in a multi-carb set-up. By the way,....the approximate airflow CFM of one Stromberg 97 is 155 CFM. The approximate CFM potential of four 97s on the Weiand WC4D is 620 CFM. The Stromberg 48 flows approximately 170 CFM, giving 680 total CFM in a four carb set-up.
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