I plan on using two Ford 94 carbs on a 303 Rocket Olds. But I was wondering if the two carbs together make enough CFM to get the Olds running right. The Rocket will be pretty much stock except for a Schneider 288-H cam and a 0.030 overbore. What do you guys think?
The old 2x2 manifolds I've seen were designed for the 4 bolt Stromberg "aerotype" script carbs such as model AAV-26 etc. These were also used on the stock twin carb Buick straight 8's. I have no idea on flow CFMs for those or the 94's, but I know I have seen CFMs listed for 94s on hamb. There are usually some good Aerotype pics on that "auction site". Look for 40s Cad, Buick, and 40-41 Stude as well as typing in "stromberg" under Vintage Auto Parts=fuel delivery=. I've seen some Aerotypes with 3 bolts also. How often will you run full throttle for long durations A smaller carb should run just fine, but lack the flow at the top end, like in racing. JMO
Thanks for your reply! I have two Rochester AA's that can go with the manifold. The thing is that they are in need of a rebuild and rebuild kits are pricey for them. The same goes for the airfilters. Damn difficult to find and expensive too. I have a couple of Ford 94's that are ready to run, so I figured why not run them.
i was talking with a bunch of guys about this for my motor...i was going to be lazy and run the center 2 carbs on my 6 carb manifold for my 303...and other than lack of fuel to the outer 4 cylenders they said its nothing close to what you want in cfm. the 2x2 is different than the log of course which would give you better fuel distribution but you wont get close to the performance you want. there telling me 3 or 4 is a safe bet and what they always used with best results back in the 50s and 60s. hope that helps a bit
I plan on running 2x2 94's or 97's on my 303 which should give about the same cfm as a early 4 bbl carb. I have seen these 2x2's run before on the rocket motors and they seem to be pretty good. Unless you want flat out carburetion I think 2x2 94's will be good, plus they just look a lot better IMHO.
Look at it this way: a stock flathead had what 239 cid? If one can feed that, then 2 should work okay on yours. I've run one on a 250 Chevy six, as it was rebuilt and I needed a carb for it. It worked great, but it was not a hopped up engine. Or, you could try a pair of Rochester 2g's, if you wanted more capacity.
Take a look at the primary butterflies on the stock 4 barrel carb that it came with. They are smaller than the 94 butterflies and you have 2 of the 94s. The original 4 bbl primaries worked just fine until that time when you needed to floor it and open the secondaries. The 94s will do the same. If you aren't racing it, it will never matter. If you are racing and are worried about running out of oomph on the bottom end of the quarter then you'll probably want a different carb set up. For the street they will work just fine once you get them sorted out. Also running 2 center carbs on a six pack will not lean out the end cylinders any more than a 2 bbl carb on any other V8. The air fuel mixture takes place in the carb before it enters the manifold.
An engine's CFM requirements are largely based on displacement and RPM. A 303 cube motor turning normal "street RPMs" won't need more than two 94s on it.
394's came with two barrel carbs in some models... as did 389 Pontiacs. two 94's will be fines as long as you aren't running 6000 rpm's all day. Back in the day we used to horribly over-carb our engines... now the smart guys put on six two's and only use four... and many times two.
seem to remember the typical 94 is rated at about 185 cfm but have also read that they actually flow about 165-175 the larger 1" and 1-1/16" versions will flow a little more, around 210 cfm. like said above, 300-400 cfm should be fine for a mild 303 around town
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