Howell V4 Distributor

[scooby]

This engine is my first that uses a distributor so I need some help understanding how it goes together correctly.

Here is the rotor contact assembly and rotor drawing.

The rotor contact assembly is superglued on rotor. It says in one of the sheets "the rotor inside the cap should clear the rivets by only a few thousandths" and "the rotor contact tip should be flush with rotor top so it won't get snagged on a rivet"
If the rotor contact were glued in this way that would give .005 between the top of rotor and contact tip ( .020 - (.003 + .012)) like this next picture simply shows. Why would the drawing of rotor show .020 depth and not .015?

Where the center rivet is, the piece of contact strip would be .017 below it. Does it spark from center rivet to contact strip?

Here is a pic of distributor cap and rivets that come with it.

Do I put the spark plug wires through holes in the top of distributor cap, solder it to rivets, then superglue rivets in bottom of distributor cap?

 

[gbritnell]

When I make a distributor cap I make up the rivets with a solid shank. I leave the shank long so it protrudes into the cap. I then make small brass washer to go over the shanks. I put a countersink in each washer to the point of not enlarging the shank diameter hole. I insert the rivet into the terminal end of the cap and hold it in place with the open part of the cap up. Using an electric soldering gun I solder each washer to the shank of the rivet. I then chuck the cap in the lathe and taking light cuts remove material from the shank and washer until there is only about .010 stock remaining. For my wires I strip a small amount of insulation back and then splay out the wire strands. With the wire in place in the terminal post I make a boot by sliding a piece of shrink tubing over the wire and up against the terminal. I then slide another larger piece of shrink tubing over the terminal and the other piece of shrink tubing. I then heat both pieces of shrink tubing until it forms around the distributor terminal. The reason for 2 pieces of shrink tubing is because a piece large enough to fit over the terminal usually won't shrink down enough to grab the wire so I use the smaller diameter tubing to make up the difference in diameter. I thought maybe I had a close up of one of my distributors but apparently not. The picture is of my Ford 300 inline six. If you zoom up the picture you can just make out the wire boots.

 

[scooby]

I found some pictures you had of your distributor from your thread. I looks like the rotor contact is bent to allow it to touch the center of distributor cap connection. The Howell plans don't say anything about bending it, that's why I wasn't sure if the spark is supposed to jump or not.

Foketry made his own distributor said he put a graphite contact with a small spring that keeps it always pressed against the rotor and has brass screws coming out the top. (pic)

I was thinking something of doing something like this:

Instead of press fitting the brass piece I could tap distributor cap and make brass stud/screw to hold the spring back and provide a connector. Also, instead of the rivets the distributor cap comes with, I could tap them like he did and make brass rod/screw for them.


I have these connectors (male and female) and was thinking of soldering the male ones to the end of the brass studs/screws in distributor cap and putting the female one in the vacuum connector with it being soldered to spark plug wire.

I'd appreciate your input on whether all this would work or not.

 

[lantain1982]

When I made my Howell V4 [ some time ago] I pushed the rivets into the cap then inserted a rod with about a 60 degree point on it and supporting the rivet heat inside the cap I tapped the rivet stem which splayed it out and locked the rivet in place. I bent the contact arm up to make contact with central rivet. The plug leads were soldered to close fitting brass pins which are pushed down in to the rivets and held in place by heat shrink over the cap pillars.
I found getting the the distributor to function correctly was a bit fiddly but using a multi meter will help establish contacts. Hope this is of some help?

 

[scooby]

I was thinking that if I made the 4 contacts threaded rod instead of rivets, I could use multimeter and screw in unit I get continuity then back off a little for each contact so there is only a small amount of clearance. Did you bend contact arm 45 degrees or like the pic in my previous post?

 

[lantain1982]

I purchased my dist. cap from Jerry Howell. Found that with the rivets in place the contact arm was bent up very slightly to make contact with the high tension rivet. The small amount the arm was bent should give you clearance over the s/plug lead rivets. The machining of the distributor components is fairly tight and any runout will effect the contacting. You should get an idea when you attach the hall sensor. Your are looking for 4 signals when rotated.
If you use adjusting screws as you suggested it reflects in a run out problem.

 

[scooby]

Because I'm a picture person and have to read things over and over again just to understand what's being said, here is my plan in pictures:

Step 1:

Step 2: After rivet is in secured in place, I see what a press fit would be in rivet, and what diameter I should make other end so connector can be put on.

Step 3: Solder connecter to end of brass piece

Step 4: Make tool on right so I can press brass piece in.

Are those connectors (pic where I showed male/female ones) ok to use for a connection? Feel free to let me know if anything won't work.

 

[lantain1982]

Having secured the rivet by swaging you may/will find the resultant opening is quite small and the fitting you suggest would be a fairly difficult operation. In my case I made some brass plugs which were a neat fit [finger pressure fit] into the cap pedestals. To these plugs i had previously drill out a depth and soldered the spark plug leads in place. This allowed the the plug to be pushed down onto the swaged area of the rivet, thus making a good contact.
Contact can be confirmed with a multi meter. Good luck with your ongoing project.

 

[scooby]

So I made this tool (and who doesn't like making tools) after seeing a pic of something called a tubular rivet clincher.

then turned down piece of brass that would support the other end when pressing rivet

The rivets are now secured and the hole through it hasn't changed size

The other side that had the piece of brass I was pressing the rivet against, I can tell they are not all the same height.
I used the tailstock to press, not hammer, so maybe that could be the reason for height issue

I'm debating on if I should try to press the 3 ones that stick out more to match the lowest one, not sure how hard that will be to do.

Other idea is to hold in soft jaws on lathe and face the outer 4 rivets until the are all even. The thing about that is the possibility of a rivet being faced too much and it's no longer held secure in the distributor cap.

 

[scooby]

In hindsight I probably could have avoided issue if I made the brass piece like this, with a counterbore depth equal to the rivet head height, that way it would not be compressed and cause different heights

 

[gbritnell]

For the difference of a couple of thousands it won't make much difference. If you wanted them all the same then just go back and tap the high ones a little more.

 

[scooby]

I got a new distributor cap with rivets from Howell (yeah, I know it wasn't necessary), but the rivets that came with it don't look like they are made of brass.
They are shiny and non-magnetic. Do the rivets need to be made of brass or will any metal do for the distributor contacts?

 

[RobConway]

Would you consider making your own version of the rivet with a flat face and hole to take the wire. Solder the wire into the contact and then thread the cable through the inside of the dist.cap then silastic the wire in place, from the top.

That way you could also consider the contact protruding 3mm through the inside of the cap and then the rotor could make contact on the side of the contact and not the face. That way we manage the length of the rotor and not its height. Just like a real dist rotor/ cap where the contacts were machined in the cap.

 

[scooby]

Made new connectors, because the connecters I had were too big and I didn't want to drill the distributor cap holes larger.

First, the female side that is going in the vacuum fitting/spark plug wire. Drilled, turned and made small slit


Made the male part that's going in distributor cap



Made a counterbore in delrin to use for pressing in







All together



Now that I know this will work, I'll repeat when new distributor cap and rivets come in

 

[RobConway]

Hi, nice job

Where did you buy the rubber boots for the dist cap and plug end

 

[scooby]

I googled the part number mentioned in one of the last sheets
It is vacu-tite 47410

I cut one side of them all to same length by sticking pin in them and using blade with light pressure while slowly spinning around

 

[RobConway]

Haha. Im still years away from looking at last sheets. Thanks Ill take a look at my plan set, as they do look good

 

[scooby]

I made the part that the cap will have a screw in by putting some round brass stock in a collet block, milling the contour, then transferring lathe to cut it off


I wanted a way to hold it so could align it with the cap for soldering. I tried with piece of brass with v notch on left of pic, but it didn't hold it very well, so I made the matching contour in a piece of brass and used that to clamp. I put the pin in and aligned everything


Then removed cap, soldered, flipped and did same for other side



I have a couple questions.. But first, here it shows the notch for distributor cap, and hole for locating pin

Where the yellow circle is where the key in distributor cap is

It is not at 45 degrees, so the mounts look off. I'm assuming the 2 threaded holes in the bottom the drawing had are for when the cap was held by clamps and that is what attached them.

My questions are:

1) Is this right, regarding how I have things orientated?
2) The pin mentioned in the drawing, is that supposed to stay in distributor, or do I take it out after everything is together?

Thanks