1934 Dome distributor caps

[34 fordor owner]

Hello, I had a quick question about the distributor inner and outer caps. I recently changed the spark plug wires on my car and noticed when I got the inner and outer caps back on the distributor they didn't exactly line up. The outer caps have some small spaces around the caps and they are not fit to the dome distributor but they are still hooked in. Would this cause any problems within the ignition system or getting a spark to the plugs? New to this whole thing and I am learning as I go. Thank you!

[koates]

Are you sure you have the correct caps ? In 1936 the caps changed but look the same. The part number on the 36 caps starts with 68 which is moulded into them. Your original cap part number starts with 18. The rota also changed in 1936 to match the newer cap. You just cant mix them up otherwise the engine will not run. Regards, Kevin.

[34 fordor owner]

Originally Posted by koates

Are you sure you have the correct caps ? In 1936 the caps changed but look the same. The part number on the 36 caps starts with 68 which is moulded into them. Your original cap part number starts with 18. The rota also changed in 1936 to match the newer cap. You just cant mix them up otherwise the engine will not run. Regards, Kevin.

Yes, the caps fit before changing the wires.

[Brian]

Did you fit the gasket[s] between the inner and outer caps?

[Terry,OH]

No gasket on the inner cap just between the two caps. The inner cap has to fit all the way inside the recess of the distributor and be flush to the outer rim of the recess. You can change left to right they are not side specific. Sometimes new inner caps need to be slightly sanded to fit properly They should be a tight fit by hand with no wobble.

[jchochole]

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I think I found another problem, the doofus before me changed the plugs and got the inner caps wrong. My tooth will not line up with my dist housing.

Does anyone have a wiring diagram for this 34 which shows the two left and right caps?

[Terry,OH]

if you get the outter cap up the plug wires, you will find numbers on the inner cap corresponding to the cylinder plug wire that goes into each hole.

The cylinders are 1,2,3,4 pass side front to rear and 5,6,7,8 drivers side front to rear
Those are not original Ford inner caps since the Ford cap appear slightly different. There will be no part number on the inner cap

[Terry,OH]

The one tooth, on the distributor side of the inner cap will line up with the distributor notch. The other side of the inner cap has two notches for the outer cap to fit correctly.

[dean333]

I hate those helmet distributors, I’ve always upgraded to the crab style.

[Lawrie]

There is nothing wrong with the helmet type, if set up properly and use the correct parts and gaskets.
I hope Im not jinxing my 33, as I,m off away in it tomorrow for a week
Lawrie

[38 coupe]

It takes me a while to properly set up a helmet distributor. As mentioned earlier in this thread many inner caps do not properly slide in. This can be caused by either a cap too big or by the distributor housing being warped, I have seen both. I have also found many cases of the rotor and inner cap posts hitting. Whenever I use new or unknown parts I take the distributor off the car and test fit everything. I usually have to sand down the outside of at least one inner cap and file down at least one inner cap post. Once I have to file down a rotor tang as it hit all four posts.
Helmet distributors work great if you have the patience to do it right the first time. The distributor on my 38 Phaeton was done right back in 2007 for another car. I swapped it on to my 38 when the other car got sold and it still runs great with the same spark plug wires, rotor, cap, etc. now with over 15 years and over 10,000 miles.

[Lawrie]

All the gear in the helmet on my 33 must be working ok, as I'm out in it today.
I had just done a big pull up a steep hill in 2nd gear,
No drama

[petehoovie]

Originally Posted by Lawrie

All the gear in the helmet on my 33 must be working ok, as I'm out in it today.
I had just done a big pull up a steep hill in 2nd gear,
No drama

[Lawrie]

I will post some pics and stuff on my short week or so trip.
I am off out to meet up with the son my sister had to adopt out 56 yrs ago .
Lawrie

[rockfla]

Thanks for sharing Lawrie, fantastic as always