97 vs 94

J

jeepguy1948

Well-known member
Could one of you gentleman explain to me how a 94 differs from a 97? I have worked with 97s but have never even seen a 94.
 
The 97 uses a mechanically operated power valve, under the accelerator pump. The 94 uses a vacuum operated power valve. Both work well as a single carb but the 94 is more trouble when using dual carbs. For touring 1 carb is all that is needed.
 
Thanks you Jim, that article spells out the differences pretty clearly. Might be interesting to try a 94 some day, I’ll be keeping my eyes open for a good affordable used one (new is out of the question LoL).
 
I know that the Stromberg "97" has .97" venturies, I suspect that a "94" has .94" venturies.
 
I had a new Stromberg 97 on my warmed up a(I pulled it off to put on my mum's hopped up burtz with a second new 97), I replaced it with a one of the later larger 94's from a yblock, there doesn't seem to be much if any difference in power between the two but the off idle and low speed engine characteristics are much more responsive with the 94, I think the 94 drives nicer than the 97 and my town sedan does have a little better fuel mileage than the 97, especially around town, in a single carb setup I'd definitely use a 94 again
 
The Holley design for metering is better than the Stromberg design. The big problem in the modern era is the fit of the early Holley power valves and the fact that they don't make that particular design any more. Modifying the body to fit the modern power valve can be done. Charlie NY still does that stuff but we can't PM him on here any more. Holley still makes all sorts of different vacuum level power valves. A person has to use the best size number for multiple carb use. In some cases, certain power valves have to be removed and plugged so that the flow fits with the engine size for best running mixture ratio or F/A ratio. It takes some tuning to get it just right.
 
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Good information, Thom leads me to want a 94 but rotor shows it to be either impossible or at least not economically feasible :(
 
alexiskai said:
Consider the Stromberg 81, also available new. (Price shown is MSRP. There are a number of independent Stromberg dealers who will sell it to you almost at wholesale. Check around.)
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I ran an original 81 on a hill climb, it ran very well but It went up the hill about 3/10ths of a second quicker with the bigger 97. For most touring either will work nicely.
 
3/10ths of a second? Wow, your a better driver than me I would never be consistent enough to determine any numbers even close to that LoL.
 
jeepguy1948 said:
Good information, Thom leads me to want a 94 but rotor shows it to be either impossible or at least not economically feasible :(
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It's neither impossible nor expensive to work with the 94s. The challenges are minimal and 94s are less expensive. A person just needs to know what to do and where to get what's needed. If you're unsure then get the 97s.
 
Sourcing the correct power valve for the 94 is nearly impossible new. However, harvesting the power valves from junk 94’s works..7.5 inches vacuum is the correct setting for an A, the valves are stamped with the crack pressure.

94 is a ‘smart’ carb, it listens to engine vacuum to enrich the fuel air mixture during acceleration.

Couple it with a mechanical advance distributor, high compression head and a more aggressive cam than stock and the engine really wakes up.. Ford detuned hell out of them.. the best part is the torque rises as well , that's what makes the A fun to drive stock.. it funner with the engine efficiency is raised and potential is realized.Some believe you are abusing the engine ‘hopping’ it up.. it’s the contrary, it actually runs efficiently and cooler, with no risk to properly maintained rod and main bearings
 
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Holley made an equivelent to the Stromberg 81. It is the Holley 92, with the small venturis and was the replacement for the S 81 on the Ford v8 60 engine. Very nice touring carb and good on multi carb setups. A little more CFM flow than the S 81. Cheaper than the S 81 if you can find one. (Like JB above with the Stroms, the Holley 94s were a touch quicker up the hill than the H 92,; but it does run nice.
 
"Smart carb"??? I always tell people that carbs are stupid, all they know is how much air is flowing thru them, and they add the necessary amount of fuel, as needed. -:)
 
It’s smart in the sense it uses engine vacuum signal to operate as opposed to just air flow, the Stromberg’s emulsion tube design runs on air flow, the Holley airflow and vacuum.. ok maybe smart is a poor choice of words Mr B, better to say above or below the throttle plate.
 
I have a 94 Carb did not install it because they say the reproduction power valves are not good and leak, if you check out Charlie Price on YouTube, he claims to have improved and sell his own power valve for the 94.
 
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