1949-53 8ba Flathead Electronic Distributor
- Thread starter 34pocho
- Start date
51 MERC-CT
Well-known member
Sounds more like a rich fuel mixture problem rather than spark intensity.
Phil Gillespie
Well-known member
As above diagnose the problem first.
What carb are you running? Jet size? What is your ignition timing set at?
What plugs are you presently running?
I am running an 8ba with a stromberg 97 and chev type distributor with a vacuum advance from Charlie NY. This set up runs great.
Phil NZ
What carb are you running? Jet size? What is your ignition timing set at?
What plugs are you presently running?
I am running an 8ba with a stromberg 97 and chev type distributor with a vacuum advance from Charlie NY. This set up runs great.
Phil NZ
Gene1949
Well-known member
I would ***-ume you are running it at the drag strip ONLY.
Because if you are trying to run it on the street you don't have near enough advance [ignition timing] in that motor
A good place to start assuming the carb if functioning normally.
MSD makes an "all in one" electronic distributor for the 8BA. I can't speak to the reliability but friends are very happy with the unit
Check if you have a mechanical advance/retard - if so you don´t need the vacuum and have enough advance (probably too much as the std flathead seems to be happy with 22 degr or thereabouts). Never tell if you run a "fake" stromberg carb from GB as you will not get advice (happened to me).
Seriously check the fuellevel in your carb and check the pressure reaching your carb. I went well below the recommended 2,5 psi and lowered float level a lot to get rid of the rich smell following me. (I´m running two carbs)
What plugs are you running? If they are of too cold a range they will never get hot enough under running conditions to burn the carbon soot off.
So first check is that the float valve closes properly, next step is to check that carb does not leak into the manifold. Check ignition settings, go for a ride longer than 1/2 hour to warm the engine a bit and have then a look at the plugs. If they reach their working temperature and the engine is in recent tune and not an oilburner, they should not be black and/or wet. If engine runs good, try hotter plugs first. If engine is low on compression, unwilling to rev and down on power, it´s probably time to have a look inside.....
Seriously check the fuellevel in your carb and check the pressure reaching your carb. I went well below the recommended 2,5 psi and lowered float level a lot to get rid of the rich smell following me. (I´m running two carbs)
What plugs are you running? If they are of too cold a range they will never get hot enough under running conditions to burn the carbon soot off.
So first check is that the float valve closes properly, next step is to check that carb does not leak into the manifold. Check ignition settings, go for a ride longer than 1/2 hour to warm the engine a bit and have then a look at the plugs. If they reach their working temperature and the engine is in recent tune and not an oilburner, they should not be black and/or wet. If engine runs good, try hotter plugs first. If engine is low on compression, unwilling to rev and down on power, it´s probably time to have a look inside.....
tubman
Well-known member
First of all, it is not my intention to turn this into a "points vs. electronic" discussion, especially since the O/P is a new member. That being said, I would like to make some comments on post #5. First of all there are thousands of flatheads out there running mechanical advance only distributors on the street with no problems. The only problem with them is that they may not deliver optimum fuel economy. I am running two myself, one on my '51 Ford and one on my "Hot Rod" engine. I use the '51 as my summer daily driver and it performs flawlessly. It delivers 14 MPG around town and 19 MPG on the highway with no OD.
Secondly, the method that a distributor uses to advance the spark has absolutely nothing to do with the amount of total advance. Flatheads like a total advance in the low 20 degrees neighborhood, and whether that is done solely by vacuum (as in a stock Load-a-Matic) or mechanical only, or a combination of the two is irrelevant. The main problem is that most aftermarket distributors for flatheads come with a built in advance curve more suited to an overhead valve engine than a flathead. Most have a maximum of about 36 degrees, which is fine for a SBC but way too much for the average flathead. If the present distributor was converted by someone who knew what they were doing (and most do), it will have the total advance limited to the proper amount, and if in good shape, should be a perfect fit for the engine.
I realize that it may be tempting to throw the latest gizmo at a problem and hope that it fixes it, but that way is usually counter-productive and often expensive, I checked and see that the MSD unit mentioned above is north of $600! I had an MSD distributor in a 276 Merc in a '36 coupe I had 25 years ago, and while it produced a good hot spark, the engine always had an overheating problem. It turned out that the distributor had the dreaded "Chevrolet curve" and the engine was running way advanced.
As another poster has already mentioned, this sounds more like an over-rich carburetion problem rather than an ignition problem. I would start addressing this problem by checking the fuel system. I would check that the fuel pump is putting out the proper pressure (2 1/2 to 3 psi) and no more; this is one case where more is not better, as too high fuel pressure will overwhelm the needle valve in the carburetor and produce an over-rich condition. If the fuel pressure is proper, I would then turn my attention to the carburetor. Is it dirty? Has it got the proper jets? Does the power valve leak? Any one of these conditions can cause the problems you are experiencing. If you feel you are not up to tackling the carburetor yourself, there is a member on this forum ("Charlie ny") who is an absolute whiz at these things and can make your carburetor perform better than new. And I'll bet it will cost about half what the fancy MSD unit will set you back, and solve your problem. I am making the assumption that the O/P's vehicle has a stock carburetor.
I also find the last line in the post recommending an MSD distributor to be quite curious.
Secondly, the method that a distributor uses to advance the spark has absolutely nothing to do with the amount of total advance. Flatheads like a total advance in the low 20 degrees neighborhood, and whether that is done solely by vacuum (as in a stock Load-a-Matic) or mechanical only, or a combination of the two is irrelevant. The main problem is that most aftermarket distributors for flatheads come with a built in advance curve more suited to an overhead valve engine than a flathead. Most have a maximum of about 36 degrees, which is fine for a SBC but way too much for the average flathead. If the present distributor was converted by someone who knew what they were doing (and most do), it will have the total advance limited to the proper amount, and if in good shape, should be a perfect fit for the engine.
I realize that it may be tempting to throw the latest gizmo at a problem and hope that it fixes it, but that way is usually counter-productive and often expensive, I checked and see that the MSD unit mentioned above is north of $600! I had an MSD distributor in a 276 Merc in a '36 coupe I had 25 years ago, and while it produced a good hot spark, the engine always had an overheating problem. It turned out that the distributor had the dreaded "Chevrolet curve" and the engine was running way advanced.
As another poster has already mentioned, this sounds more like an over-rich carburetion problem rather than an ignition problem. I would start addressing this problem by checking the fuel system. I would check that the fuel pump is putting out the proper pressure (2 1/2 to 3 psi) and no more; this is one case where more is not better, as too high fuel pressure will overwhelm the needle valve in the carburetor and produce an over-rich condition. If the fuel pressure is proper, I would then turn my attention to the carburetor. Is it dirty? Has it got the proper jets? Does the power valve leak? Any one of these conditions can cause the problems you are experiencing. If you feel you are not up to tackling the carburetor yourself, there is a member on this forum ("Charlie ny") who is an absolute whiz at these things and can make your carburetor perform better than new. And I'll bet it will cost about half what the fancy MSD unit will set you back, and solve your problem. I am making the assumption that the O/P's vehicle has a stock carburetor.
I also find the last line in the post recommending an MSD distributor to be quite curious.
Last edited:
1948F-1Pickup
Well-known member
Does anyone know what would be the best electronic distributor to use on my ‘49-53 8ba Flathead? My spark plugs are constantly turning black. I think I need a hotter spark. I’m currently running a converted single point sbc distributor and it doesn’t have a vacuum port. Thanks
Part of your situation undoubtedly (as other have mentioned) is carburetor-related. I would check into that situation first.
Also, the lack of vacuum advance on your single point converted GM distributor is also contributing to your fouled plugs situation. (to say nothing about lost fuel efficiency)
At idle and low loads a properly set up vacuum canister will have the engine running more advance, which keeps plugs cleaner, makes for a cleaner combustion chamber burn, etc.
I don't know on the flathead but on an OHV engine, properly tuned with a factory dual point vs that same engine properly tuned with a single point distributor with vacuum advance there's probably 2 mpg difference right off the bat and much cleaner (and longer lasting) sparkplugs with the vac can.
On my 8BA I run one of those GM distributors too, with an old Hays reluctor and a Chrysler pickup. It's got a vacuum can as well, which I spent a lot of time dialing in. Works like a charm. Plugs stay clean.
