Technical 48-53 8ba flathead engine issues

Im having an issue with my customers flathead. He decided to put a 2 duece intake on the motor purchased the carbs from Charlie Price. The issue I have is the motor seems to run rich on the rear cylinders 4 & 8 the remaining cylinders are firing great. So I changed the plugs to #12 hotter plug, wires to taylor and decided to change the distributor to a new mallory also. Fired up beautiful reveved up nice. Took it for a drive got back pulled the rear plugs and noticed they were blacking again. In a normal engine its valve seals. Not sure on flathead ? or I also noticed that the carbs I purchased from charlie they're progressive but the rear carb is right over the two pistons that are rich ?????and that carb still has jets usely they're blocked off ????. if there were a vacuum leak they would be running lean and not rich ??. I assuming the rear carb is the culprit any suggestions ......
Rubydoo

 

Don't you mean power valves and not jets?

 

I would advise checking the offending cylinders with a compression test before making any carburetor or intake changes.
Then let’s get into air and fuel issues.

 

That’s the first thing I usually do. A compression test.


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If it were me. I would ditch the progressive linkage. Go straight. Set both carbs to 1 1/2 turns out on the mixture screws. Make sure both carbs butterflies are opening equally. And buy yourself a vacuum puck. It goes on the top of the carb to make sure one carb isn’t working harder than the other. If that doesn’t fix the problem. I would make sure both carbs have the same size jets and that the accelerator pump is in the middle hole of the throttle rod. If it still runs rich I would change the jets to a smaller size


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Will the original Load -a-Matic distributor with vacuum advance work properly with dual carbs?
I think I have read that it may give problems when trying to use multiple carbs.

 

Does your manifold look like this or are the carburetors centered?

 

We really need to know more about the actual setup he is running before making blanket recommendations. I also have some tentative recommendations, but will wait for more information.

 

I had this exact same problem on my 51 flatty.
I am running an Edmunds intake. When I had it setup for progressive (per vintage speed recommendation) the rear cylinders were always a bit richer than the rest, and I could never get it to run right (even after replacing the carb base of the secondary carb for a better seal at the butterfly's so i didn't have to richen the primary up to compensate for the air leak...)
I finally got sick of messing with it and sent the carbs to Charlie Schwendler (CharlieNY on the FordBarn.)
He rebuilt the carbs, set me up a straight linkage, tuned them on his test engine and sent them back to me.
I took them out of the box, bolted them on and it ran great... I haven't looked back.
Turn around time was good and the price was very reasonable... he even provided some great phone support when I had a question about plugs and timing.
Here is his email address ([email protected])
You can PM me if you want his phone number
Chappy

 

^^^^^^^
This is probably the best solution unless someone wants the gain the experience (and frustration) of doing it themeslef.

 

I bet Chappy's solution was because CharlieNY rebuilt the junk carbs. Do a search on Charlie Price.

 

For clarity, I did the carb rebuild on a vintage set of 94's. but i did use vintage speed progressive linkage, power valve block off, and carb base (all at Mr. Price suggestion). And it ran much better than it did when I started. But I still wasn't happy with it...and it had the same symptoms as the OP.
I had heard good things about CharlieNY and contacted him and I am glad I did.
Chappy

 

First problem you have is that the carbs come from Charlie Price next as posted above two deuces are not meant to be run progressively. Link them together and tune them as one by using a uni-syn gauge and set the mixture screws with a vacuum gauge. The difference you experience will be surprising.
Ronnieroadster

 

This is the second time in two weeks we have had a thread on here from someone who got a bunch of parts and advice from Charlie Price and ended up with nothing but problems. When will people learn to stay away from him? Far, far away.

To me, it is obvious that manifolds like the one I pictured were designed to be run with progressive linkage, with the front carb as the primary. I have never used one, but it might be interesting to try to get one to run that way. If you tried to run both carbs at the same time with a straight linkage, I would expect you would have fuel distribution issues all of the time; it certainly would not be ideal. Now look at how the front carb is almost in the same position as a stock manifold. This tells me that it may have been intended to be used as a primary, giving relatively even fuel distribution at normal speeds. Only when it is fully open would the second carb cut in, feeding extra fuel to the rear set of intake ports. While this also would not give ideal fuel distribution, it would only be at WOT, which can mask a lot of problems. I would think the secondary (rear) carb should have no idle circuits, well fitted throttle blades, a plugged power valve, and perhaps smaller jets.

As I said, I have never done this, as I am a "Super Dual" guy and have avoided these things like the plague, but my curiosity has been aroused and I'd really like to see what could be done with one. (On somebody else's car.)

 

Ruben sent me some pictures of his setup, and he has an old Almquist manifold with the evenly spaced carbs that requires a straight linkage.Too bad; I'd like to try the dual progressive setup with the proper manifold just for fun some time.

 

I have run the Offenhauser street manifold for years. It is the one in Tubman's picture. It is set up that way so you can run the generator in the stock position but an added advantage is that you can run progressive linkage on it . There is no problem with fuel distribution as some may think. Think of a stock manifold and the difference in runner length for the end cylinders from the middle ones. Think of the runner difference in a stock inline 6 cylinder. The slight runner difference is not a big problem. I have run two '94s on this manifold for 20 years in both progressive and straight linkage. I didn't really notice much difference in performance from one to the other and I have never worried about gas mileage. The one problem I had was getting it to idle properly with the progressive linkage. If I shut the rear carburetor throttle blades right off they would stick in the bores. If I opened them a bit so they wouldn't stick then they bled air in and messed up the idle. I have since found you can buy bevelled throttle blades so they won't stick but haven't got around to it yet. I am going to go back to the straight linkage I think.

 

The only 2 carb manifold I would consider running progressive linkage on is the Edelbrock Slingshot.

 

I'd still like to try it. It looks to me that it would work better than a "Slingshot" but you'll never know until you try.

 

The two deuce Flathead intake manifold no matter what design that being set back carbs to clear the generator or the standard layout equally spaced apart all of them will work perfectly with both carbs running together all the time. No cylinder washing will take place this design was really never meant to be progressive. Since some have had good results running two carbs with progressive linkage I have not tried that so far. Not sure I ever would since the all out pull from two carbs working as one is a really good kick in the but feel when they are tuned correctly.
Ronnieroadster