1938 Ford Deluxe Distributor

[Will D]

1938 Ford Deluxe late model with 24 stud V8. From what I can tell from comparing pictures and parts on MacAuto, the distributor on this thing is a 46' - 48'. When setting the dual points, do I still set dwell at 22 1/2 with combined 36?

I found instructions on how to set the advance with 2 rulers off the key on the shaft, then found a directions for a template to set dwell. Once advance is set and points gapped, do I further adjust the points to achieve correct dwell? Sorry I'm new to all this....

-Will

[deuce_roadster]

Plenty of info here if you search for it. Sounds like you have the right idea. One advantage of running it on a machine is you can let the rubbing blocks on the points seat in by running it for a while and then recheck the dwell as it will have changed.

[JSeery]

Will, do you understand how the vacuum brake works and the mechanical advance? It is different than modern vacuum advance. It works as a brake to slow the mechanical advance when the engine is under a load. With modern fuel it can normally be backed off until it is appling light pressure.

[35fordtn]

Ensure you spin it in the direction it is intended to on the engine or else it will be off.

I set the LH set at 22 - 22.5 and the combined at 34 if new points are used, and a combined of 36 if you are setting up used points.

When you say setting the advance using rulers, I presume you meant the initial timing.

[Will D]

Originally Posted by JSeery

Will, do you understand how the vacuum brake works and the mechanical advance? It is different than modern vacuum advance. It works as a brake to slow the mechanical advance when the engine is under a load. With modern fuel it can normally be backed off until it is appling light pressure.

Thank you. When I pulled the distributor off it looked like the vacuum hole was filled with gasket maker (not sure if intentional or unintended) and the brake had a 1/8 groove worn into it. I've ordered a new brake, is it an O-ring that should be around brass vacuum inlet on back side of distributor?

What kind of fuel should I be running? Previous owner was using 94 octane. Is that necessary being it's not a high compression engine?

[Will D]

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Originally Posted by 35fordtn

Ensure you spin it in the direction it is intended to on the engine or else it will be off.

I set the LH set at 22 - 22.5 and the combined at 34 if new points are used, and a combined of 36 if you are setting up used points.

When you say setting the advance using rulers, I presume you meant the initial timing.

Yes I meant initial timing. How do you set the advance? I read a lot of guys saying to advance timing 4 degrees.

[JSeery]

I read a lot of guys saying to advance timing 4 degrees.

There is a screw that is located on the side of the housing, should be some hash marks as well. It is ID in these drawings.

What kind of fuel should I be running? Previous owner was using 94 octane. Is that necessary being it's not a high compression engine?

Should run fine on 87 octane, no need for anything higher.

There is some information you might find interesting on Bubba's site: http://www.bubbasignition.com/crab-42-48.html

Added a photo of a distributor gasket.

[Will D]

Awesome, thanks for the link.

[Will D]

Originally Posted by JSeery

There is a screw that is located on the side of the housing, should be some hash marks as well. It is ID in these drawings.

Would I be correct in thinking if advance screw is slid all the way to top toward vacuum brake neck it would be no advance? And as you slide it down is a degree for each hash mark for advance?

[JSeery]

No, that would not be correct, LOL. The center position is the starting point and down is advanced and up is retarded (I think). Believe most set it up two marks advanced.

[tubman]

I'm an 8BA guy and know nothing about these old front-mounted distributors, but I have to ask, Can't you set the initial timing on these like everything else? I hardly ever use a timing light any more, but use a vacuum gauge instead, especially on modified engines. Unhook and plug the vacuum line, advance it to the highest vacuum reading, and then retard it just a tisch?

[JSeery]

Originally Posted by tubman

I'm an 8BA guy and know nothing about these old front-mounted distributors, but I have to ask, Can't you set the initial timing on these like everything else? I hardly ever use a timing light any more, but use a vacuum gauge instead, especially on modified engines. Unhook and plug the vacuum line, advance it to the highest vacuum reading, and then retard it just a tisch?

But you have very limited ability to do that, the timing is mainly set by the points gap. The distributor itself is fixed and only allows for fine tuning with a side adjustment screw.

[tubman]

Then why do they have the slot and the bolt on the side? Once you get the dwell (or gap) set right, are you telling me that there is not enough range on the bolt and the slot? I really can't see moving the gap to 27 degrees (or even 40 degrees) just to get the timing right.

[flatjack9]

There is no timing pointer on the early engines. I set the dwell and timing on the Sun machine. On the engine the timing can be varied up or down by loosening the bolt on the side and making an adjustment if wanted. The distributor body itself is fixed when bolted in.

[tubman]

I am not totally unfamiliar with the early distributors and know enough to know that moving the bolt on the side moves the point plate in relation to the cam and rotor to change the timing. When I use a vacuum gauge on a later engine (flathead or other), I completely disregard the pointer. So I guess my question is still, "Why won't this work on the early front mount distributors?".

[JSeery]

Never heard of anyone setting the timing on a crab with a vacuum gauge, so I'm not the one to answer this question. Here is what Bubba had to say on the carb adjustment once the initial setup is done.

Normally, if the points are set correctly, the Index slide will be one notch counter-clockwise from center ... not centered. No matter what, it needs to be set on each distributor. Each notch represents 2 distributor or 4 crankshaft degrees. This means that on an 11A distributor you can expect 22 degrees of mechanical advance PLUS 4 degrees for each notch. If you want more than 34 degrees (!) at the third notch, you can fiddle with the point gap and squeeze out a little more advance.

...8 degrees of mechanical advance means the weights will add up to 8 distributor degrees OR 16 crankshaft degrees as the engine revs up. The later 11A will add up to 11 dist or 22 crank degrees. The crank turns 2X for every 1 distributor rotation.

4 degrees per notch is quite a bit, so guess it would work, I just have no experience with trying it that way. Sounds a little awkward, but?

[35fordtn]

Moving the adjuster down advances the timing on the 42-48 distributor you have pictured on the 32-41's it is opposite. Setting it in the middle does not mean that is the starting point. You HAVE to set the timing on a machine or fixture of sorts. That determines the starting point at 2 degrees BTDC

[JSeery]

Ya, didn't word it very well. Was trying to say setting around the center is a goal for a starting point. I don't set these up, it is one thing I always have done.