Suggestions for mild cam & muiltple carb setup with Columbia rearend

[flathead47]

Looking for some input. I am installing a Columbia in my 47 Ford convertible , it has a Edelbrock 3 x 2 carb intake with three 94's installed , only the centre carb operating , other 2 carbs blocked off. I am not sure what cam is installed in the motor , but would like to install a mild street cam with a working muiltiple carb setup , 2 x 2 or use the existing 3 x 2 setup , 97's or 94's. Do I need to worry about vacuum levels with the mild street cam & Columbia operation. What recommendations / setups are you using with your Columbia ? Thanks

[drolston]

I am running Offy 3x2 97's on progressive linkage on a 284" 59A/B. The key to trouble free operation of 3x2 anything is attention to detail in setting up the linkage. First, do not buy the cheap linkage; it flexes. Be sure the throttle shafts are not worn; air leaks there cause idle adjustment problems. Be sure there is no sticking of the throttle plates when coming off of full closed, or binding of the throttle shaft at any point. Important: set up the linkage with the carb tops off, so you can closely observe that both end carbs are completely and tightly closed when with no pull on the center throttle. Both end carbs need the driver side return/close spring. Fully close the idle adjust screws on the end carbs. Idle is completely controlled by the center carb.

I am very pleased with the street performance of the Schneider 248f cam. The low end torque is excellent, which is essential for drivability with the 3.25 rear end gears I am running to get Interstate speed without going to Columbia. Vacuum at idle is 15-16 psi, versus 17-18 for a stock cam. Should not be a problem

[john in illinois]

I agree ^^^

I have 2 97,s on a 276' engine. I also have the Schneider 248 cam with a 3.25 rear end. The cam has torque at a low rpm and also good high speed power. I am very happy with it.

Should work well with a Columbia.

John

[blucar]

The engine in my '36 cpe is a 59AB that has extensive modifications, .60 over bore, 9.0 heads, Weber F1 cam, Offy Super manifold with two 97's and an HC ignition. The Columbia under my car is a '46-48 unit w/3.78 ratio. The combination works great.

[scicala]

Very good advice from drolston in post #2.


Sal

[PeterC]

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I am happy with my 59A 284cid with Schneider 270F (365 lift / 112 lobe separation) and dual 48 Strombergs - has a ScoT Blower - lots of vacuum for the Columbia

[flathead47]

Thanks for all the input ... a few more questions ..... drolston ... the progressive linkage you use , what manufacture & who sells it ? John , blucar & peterc are your 2 x 2 setups direct linkage or can it be setup as progressive. You all have used stromburgs ... better performance or easier to setup with multiple carbs. Drolston , john you both use the Schneider 248 cam , if I read the specs right it is just a bit more aggressive then the 53 merc & ford eab cam , what does it sound like at idle .... tried to find a sound clip , but could not. Can you all post pictures of your carb linkage setups ... Thanks Ian

[john in illinois]

The 248F cam is a low end torque cam with good power at all rpms. This is what I wanted using .325 rear gears. It has a fairly smooth idle. I went back and forth with wanting a rumpetty cam. Now every time I drive it I am glad with my choice.

I would suggest you buy JWLs book flahead facts. He has chapters of dyno tests and recomendations for cams and carbs.
http://www.vanpeltsalesstore.com/L-1...son_p_511.html

Also Jerry at Schneider cams could help with cam recommendations He helped me decide.

I have straight linkage.

John

[PeterC]

My dual 48 Strombergs are direct linkage - both with choke plates present- however only one choke plate functions while the other is locked in the open position.
Peter

[drolston]

You are right, the stock '53 Merc cam is a pretty good street cam; that is what I have in the '34 pickup. The Schneider 248f has a little more lift, duration, and overlap, but is still a pretty mild cam. You will not impress anyone at the drive-in with a raucous idle, but you will appreciate the tractability driving in traffic, and the neck-snapping mid-rpm throttle response.

I used Stromberg progressive linkage from Summit Racing:

https://www.summitracing.com/parts/sbc-9246pro

At $175, three times the price of the cheap "universal" product, which is prone to flexing and binding. To allow banjo fuel fittings and retain the hand throttle on the center carb, I put my 97's on 2" risers and inverted the linkage to swing below the carb base, instead of above.

My three reasons for Stromberg 97 versus Holly 94: 1) No blown out leaky power valve problems, ever. 2) You can pull the horn off of the 97 and precisely adjust the float level; the fuel inlet and float valve are on the top of the '94 and setting float level is a pain. 3) They are more "traditional hot rod" and just cooler looking. But the Hollys work fine and are cheaper.

[drolston]

John,
I love those air cleaners. What are they and where did you find them?

[john in illinois]

Drolston,thank you. Nothing like 3 dueces . I like your engine.
The air cleaners are made of pretty simple parts.
Bases from speedway louvered air cleaner. I like the clamp on mount rather than screw.

Top covers from Speedway 4” air cleaner 910-11018

Filters are K&N [url]https://www.knfilters.com/search/product.aspx?prod=E-3130&pkid=5877701&rw=1[/ur

John

[flathead47]

Thanks for the pictures & info on linkages , good looking setups .... john I will investigate jwl's book ..... so the 248f has a smooth idle only , but is a good performer from low the high rpm. John you are using the sling shot & drolston you are using spacers on your manifold , do you think the length of the runners are helping with the performance of this cam ? Drolston from the pictures it appears this is the setup in your avatar 41 coupe , my 47 convertible would be close to the same weight , if I read your comments right your are very happy the modifications you have made , they are good all around , in town & on the highway.

[drolston]

The setup described is in my '41 coupe. The carb risers are supposed to improve torque, but only effective at high rpm. I used them only so I could invert the progressive linkage. Doesn't hurt that it puts the chrome carbs up where they can be seen better. Yes the performance is very good in town; I can get away with 3.25 rear end gears because of the torque of the 284" engine. Would not recommend gears that tall for an engine smaller than 276". Performance on the highway is great; cruises happily and quietly (for a flathead) at 65 to 70, at about 2600 to 2700 rpm. 17 mpg highway. At those speeds you need Bendix brakes, at least on the front.

[blucar]

FWIW.. The engine in my car was originally built in 1954, last rebuild in 1961. the car was originally my daily driver, getting me to work, etc., but then on weekends I would run it on the drag strips and/or street racing from time to time. When the engine was rebuilt in '61 it was de-tuned a bit, lowered the compression from 10.1 to 9.0 to make it more drive able. The Weber F1 cam was not a very radical grind, good performance, a little lumpy on the idle. Howard made a cam called an M8 in the early '50's that was very popular for street use, I wanted the M8 but got talked out of it.
I think the big plus on the Stromburg 97's was the ease of re-jetting, which was a constant function if the car was driven daily. My job for two years required me to drive to different elevations, where I might have to stay for several weeks. I carried a box of jets and the special jet wrench in the glove compartment to reject the carbs as needed. The oil bath air cleaners on my engine are not pretty, more practical compared to the traditional chrome bonnets, and they are quieter.

The linkage on my carbs is direct, and I have always ran a fuel block mounted on the firewall to distribute the fuel to the carbs.

[tubman]

"blucar" - It's not real obvious from the picture, but that is a "super" dual manifold, isn't it?