I have a 1950 ford flathead with a ford ab or holley 94 carb that i rebuilt, it starts and idles fine, it has 18 inches of vacuum, but the car will just not get up and go. It boggs down and gets stumbley and doesnt flatten out. Theres #50 jets and the stock or at least last rebuild powervalve because that one didnt leak, the one in the rebuild kid did. The idle mixture screw on the drivers side does absolutly nothing while the one on the passengerside works.The plunger is in the middle hole. I have cleaned the carb multiple times blew it out and still the same problems. any suggestions on what to try or if i should get different jets or power valve,the engines all stock.
anyone? iv searched all over the internet and could only find people doing duel carb setups. so tuning doesnt apply.
That carb should have #56 jets in it, at least. If it idles fine, the problem isn't the mixture screws. You should notice a difference when adjusting the screws though... What's the condition of the nozzle bars? All the holes clear? I'd be checking the main jets for debris/clogging if it's flat at speed (ie: when it's running on the main jets) It sounds like it's not getting enough fuel at speed. Are you taking the vacuum signal from the carb port? Are you sure it's not leaking vacuum there? Flatman
The cheapy kits have a blue rubber accel pump seal, they dont seem to even touch the wall of the bore, so that could be something to look at.. does it squirt a shot of fuel when the throttle is cracked? If its a stock 8BA have a good look at the distributor, they can be a major source of tuning problems due to their marginal metered vacuum signal setup. when you say blew it out do you mean completely dissasembled and checked every passage/orifice?
I have been using leather accelerator pumps in those because the ethanol in the gas is too dry and rips the blue pumps up.You also have to be careful about the power valves you use-some of the new ones don't seal right on the casting. It also sounds like something is still clogged,if you need help pm me I'm in Jersey too.
The stock jets are # 51's, so you are close with # 50's. Having an idle mixture circuit not responding is a sign some passages are not clear, as has been suggested. The use of a spray can carb cleaner works great in checking and cleaning all the small passages and circuits. Also, make sure you have the accelerator check ball installed at the bottom of the pump well, under the circlip. Bob
The checkball is installed, the plunger pumps gas ,i have cleaned the carb throughout with a total dismantal, i blew everything with carb cleaner and compressed air. i will take it apart once more and see what happens. The vacuume reading was taken from the port that goes to the wiper, if this is the wrong port should i hook it up to the vacuume advance port instead? what size powervalve should be installed here.
I'd run a 7.5 PV. Correct me If I'm wrong. Vacuum pressure divided by 2. Which would make yours a 9 PV, but that sounds high. 7.5's are a good starting point. Have you set the float level correctly? If the idle screw isn't doing anything, I would suggest it's a vacuum leak.
i set the float to the specs in the rebuild kit but if there is a better spec or one you guys know works let me hear it.
Is it the right carb for the engine? 8BA's use a different carb than 59a's, the venturi vacuum advance won't work with anything but the proper carb, causing symptoms much as you describe.
50' Flathead, assuming it's 8ba not a 59a right? Yes this is a dual carb. thread but the float settings still apply. http://www.jalopyjournal.com/forum/showthread.php?t=429393&highlight=holley+94+float+settings
The stock power valve is 7.5. The wiper port on the intake is OK for an engine vacuum reading, not the distributor port on the rear of the 8BA carb. Have you checked or do you know what the timing and dwell are? Should be 2° BTDC ( pionter lined up with the "bump" on the pulley) with the distributor vacuum line disconnected and plugged. Set dwell to 27°. Your 18" vacuum reading sounds good and is normal. Bob
It says ford 8ba on the side of the carb, im gonna try putting in a 7.5 pv and some 56 jets and see how it runs, after i get it running i will check the timing and dwell meter, i have one just never had any car old enough to use it on either they were converted to hei from points or it already had hei, this car is the first that had points that i get the chance to work on.
If this is a stock engine I wouldn't put 56 jets in. 51's if you want. That's just me though. What PV was in the carb now?
51 jets are correct. 56's are used in the Y block carbs. Curious that it idles well without one circuit working. I would be suspicious of the power valve leaking. If it is, it would allow gas to go down the vacuum passage directly to the engine. Still you would think that that would effect both idle screws. Also, look down the throats while idling to be sure no fuel is coming from the main venturis at idle. Also, the marking on the power valve will have nothing to do with how a stock engine will idle.
Ok fellas i got the carb reassembled with a newer style 6.5 pv modified the spot to clear it. I stuck in 59 jets because those are the smallest in my jet kit from my camaro, and bolted it back together and it runs great, i forgot to mention this car has duel 1 3/4 exhaust and thrush turbo mufflers if it matters. Im gona go to the speed shop on monday and see if they have any jets that are smaller in the 56 range or smaller. Also put in new cap rotor wires and plugs and point.after i got the carb to work fine. And now its smoothe as silk but i cant go for a test drive because as i was pulling out of the driveway the brake pedal went to the floor.
Great! Yeah don't think the exhaust would let you run 59 jets over 51's. Caps, rotor, and plugs will always help. What was your old PV... just curious.
Glad it's running fine. Those jets are way too big. Since you haven't been able to drive it, you've only been running off the idle circuit.
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