Single 97 or dual B Zeniths?

[blgitn]

I want to run with traffic at 60 mph.
If I run a 6:1 Snyder, Stipe re-grind and 1.7" intakes, which set up will breathe best at speed; a single 97 downdraft, or a scalded dog dual with "B" Zeniths?

Thanks for chiming in, and Merry Christmas!!

[DougVieyra]

Stromberg 97 will give you a bit more 'zip', but comes with a number of small iritating characteristics (leaky and finiky) and risk of dripping gas into your engine.

The Model B up-draft carburetor will give you all you need to achieve you goal of 60 mph, without the maintenance and risk hazzle of the down-draft V-8 carburetor.

[blgitn]

Thanks Doug.
Do you mean one "B" Zenith will do it, or will I need two?

[48thames]

I run a Stromberg 48, seems to work good. Only drawback with my setup is carb sits to high and runs out of gas before tank is empty with gravity feed only.

[Pete]

Stromberg 97's or 48's absolutely will not leak and will hold 8 lb of fuel pressure with a Daytona Float Valve.
http://strombergcarburetor.com/float.php

[DougVieyra]

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blgitn - Post # 3 :

My standard Zenith (made for Model A) works quite well at speeding my '28 Phaeton along at 60 mpn. My 1930 Std. Coupe, with it's '34 4-cylinder 'C' engine and it's "A' Zenith purred along nicely at 60 mph, although it did like running at 55 mph a little better.

I have had a 'B' intake manifold with 'B' carburetor ready to go on one of my cars for about 20 years now, but have never had the need to put it on, even though it threoriticly should 'go' a little faster.

My late '31 Dlx Coupe does have a Stromberg 97 on it, along with a host of other 'improvements' for 'Touring'. It is a strong and powerful running machine - More than I need or care to use. 'Speed Kills' is a slogan that does have some meat to it.

Even though all of my cars (whether Zenith or Stromberg) are quite capable of comfortably cruising at 60 mph, I seldom do so. But it can be done, easily. There are a number of reasons (subject for another thread) why I don't feel comfortable with a 72 year old man driving an 85 year old car at a sustained 60 miles per hour speed. Although both of my cars have the capacity to go 65 mph, I feel MUCH more comfortable driving at 55 miles per hour, which is quite a respectable speed for Freeway driving.

A lot has to to with the caution that comes with maturity (I like that word better than, say, 'Old', or 'Aged'). And too, along with maturity comes a lessening of skill and ability to successfully compete with YOUTH (anybody under 50) ! If one were to think of driving on the Freeway and at Freeway speeds (60 mph), one must think in terms of a Race Track, where skills, agility, reaction time, vision, a tolerance of risk, etc. all play a role. One that has the potential of being a 'life or death' contest.

I choose not to play.

- Doug Vieyra

[KenCoupe]

A couple of years ago, I drove my 31 coupe from the San Diego MARC National meet to northwest of Los Angeles - about 160 miles. I had a stock Zenith carb, 5.9:1 head and my engine has been rebuilt with lightened flywheel, B cam, etc. I went about 58 mph most of the way with no apparent problems.

[denis4x4]

First off, if you decide to go with a 97, don't screw around, buy one of the English carbs from a speed shop instead of going with a used or rebuilt carb. I also have a B with a CRAGAR head with a single barrel carb off of a late forties Ford flat six truck engine. The intake on the B is a rare Stromberg-Bendix that was sold through Ford dealers in the early thirties.

[Bob Bidonde]

It has been my experience that the Model 94 V8 carburetor is superior to the Stromberg 97.

[31Tudor]

I run a 97 with a Thomas 7:1 head. Lots of power and speed. No leaks, no problems. I have about 9,000 miles on the engine and still going strong.

[48thames]

Originally Posted by Pete

Stromberg 97's or 48's absolutely will not leak and will hold 8 lb of fuel pressure with a Daytona Float Valve.
http://strombergcarburetor.com/float.php

I emailed
them yesterday and they said that they don't make a Daytona float valve for a Stromberg 48 carb yet, but to check back in 3 month's.

[Purdy Swoft]

I haven't run a single Stromberg 97 But there are many problems that you can have with down draft carburetors that you will never have with a dual updraft setup. The throat or venturi on two B carbs appear larger than that of the two barrell 97 carb . A down draft carburetor does have gravity on its side but can flood and fill the oil pan with gas. Down draft carbs are more sensitive to jet size and fuel pressure and generally may not even run if jet size and fuel pressure isn't just right. In most cases a fuel pump and pressure regulator is required with downdraft carburetor setups.

I run my dual updraft setups on old period correct cast iron manifolds.I only use the choke on the front carburetor. This gives the same controls as for choke and GAV control as original. I leave the rear GAV closed all the time and use the GAV and choke on the front carb as normally used originally. I have had good results with original model B carbs that I picked up at swap meets used with original jets. This setup has worked great for me and actually gets better gas milage than my 31 tudor with a single side bowl Zenith.

I can't say how much actual power that the dual B updraft carb setup gives. I use this setup with a 5.9 head, Winfield super street 3/4 race cam, warmed up original ignition with a 40.000 volt flame thrower coil . I also run a model B flywheel and enlarged intake ports with smoothed exhaust ports. This car has pep similar to a modern car, I can actually accelerate up hills at 75 mph that a stock engine would slow to 30 mph on. I can't say that dual updrafts give as much power as dual down drafts. Its not a racing engine but just a mild but peppy street engine . It looks cool to me and is the easy way to go as far as dual carbs on a model A is concerned .

As for cruising at 60 mph I can do that with a stock enging in cood condition and tune .

[denis4x4]

One of this disadvantages I see using a pair of updraft carbs is the inability to fit tube headers.

[Purdy Swoft]

The original exhaust manifold is good for 100 horsepower. I run a completely gutted and modified muffler