Ignition questions - 50 flathead

[hammondite]

Hi all.


I finally was able to get a flathead 'powered' rod; a 30 Tudor with a 50 truck engine. It's an estate car; the owner died before getting it all together, but a lot of mechanical work was done.


The engine is rebuilt, with dual Primary 9 carbs on an Offy manifold (appears to be a Speedway kit) and an original (rebuilt?) distributor. And is set up for 12v neg ground.



I have two ignition questions.


1. Connecting the coil output to the distributor. I'm familiar with chevy distributors that have a wire coming out of the distributor to connect to the '-' side of the coil to the points. I haven't found that wire on this distributor. Is there a connector on the distributor, no connection at all, broken wire, or???


2. Vacuum advance connection. Where can I connect it? The carbs have no ported vacuum, the only vacuum I can find is on the manifold. My chevy experience tells me that's not useful for ignition advance.


The car also came with an HEI distributor and coil, so I could just put it in, which would solve #1. It also has vacuum advance, so problem 2 isn't solved.


For background - I built a 40 chevy coup, frame off, doing most of the work myself. And my uncle and dad are both flathead fans. My uncle has been helpful so far, but his memory is rusty on this. Unfortunately, my dad is in late stage Alzheimers, so can't help. My short term dream is to fire the engine off in the next 10 days, video it and show it to him on his birthday on the 24th.


Thanks in advance.
Paul

 

[Ggmac]

Under the distributor there should be a stud with a nut . Thats where the wire would go , if its the 8ba distributor that would of come in that motor. Just use the HEI , much better , youll need to drill the manifold or use a spacer plate under one of the carbs for vacuum. I find it hard to believe that there’s no vacuum ports .

 

[tubman]

Are we correct in assuming that the distributor now in the car is the stock "Load-a-Matic"? If so, it should have a terminal on the bottom of the distributor for the distributor hookup. It's been a long time since I fooled with a stock distributor in one of these, but I believe that's where it is. See the crappy picture

Now, if it's a "Speedway Setup", can we assume those are Speedway's "9Super7" carbs? If so, there are two things you should know : first, they are generally inferior carbs, prone to leaks, and second, they have no provision for the venturi vacuum required by the stock distributor. The easiest thing for you to do is to get a couple of the proper Holley 94 carbs with the venturi vacuum port on the back. Some people say that the "Load-a-Matic" will perform OK when hooked up to one (or both, with a "tee") of the proper vacuum ports on the carbs. I don't know; I've never tried it.

If the HEI has been converted to fit the front cover on the 8BA, it may be the easiest way to go. (It's also the ugliest). It will at least get it running (maybe). My opinion is that you should get either an old Mallory dual point or a converted standard SBC distributor for the car.

Good luck with your endeavors.

 

[TerryOH]

It would be VERY useful if you send photos of the original distributor, the intake on the drivers side. Send the Carb type if 94 then what model look for any other numbers

 

[hammondite]

Thanks, all. I found the terminal on the bottom, once you told me what to look for. That's wired in.


This is the carb/manifold setup that came with the car - https://www.speedwaymotors.com/9-Su...take-Manifold-Kit-1949-53-Flathead,37429.html


The manifold does have a vacuum port, I'm just not sure if it will be too much for the ignition.


I'm am considering the HEI ignition as well, but thought the stock one would do to get the motor started.



I'll try to add pictures. I'm using my workstation, will need to log in on the phone.

 

[tubman]

Since I know of no other distributor with the terminal on the bottom, I think we can safely assume that you have a stock "Load-a-Matic" distributor installed in the engine. Full manifold vacuum will not work with it. Also, I would have to believe that if the original owner had spent the time and money to purchase an aftermarket HEI distributor (or the time and money to have a GM distributor converted), it would already be installed in the engine. The one you have probably won't even fit in the engine. Try it; I hope I'm wrong.

If all you want to do is to get the engine started, the existing distributor should work just fine; just don't expect driveability on the street.

 

[40cpe]

There are HEI ignitions made for the flathead engines. Compare the drive ends of the two distributors and see if they appear to match. As said above, the engine will run well enough in a static position with either of them. Just set the timing to 8-10 degrees and enjoy the flathead sound.