Jump to content

ignition wires for a 248

deac

By deac
in Buick - Pre War

 Share

Recommended Posts

deac 10,000+ Points

deac

Posted
Posted

A few years back I had a 39 special coupe and was completely original with the spark plug cover. I bought and changed the spark plugs and 7mm wires and I went on a short road test and engine developed a misfire when under a load. I got back to my garage and double checked all the connections and off I went for another road test and that same type of misfire was still there. I removed the cover and drove it again and no misfire was felt. Few days of no cover on the engine it was smooth sailing. On a family trip I stopped in at Bob's and explained what was going on and they said to line the cover with an old bike tire inner tube. Got home and lined the cover and with it on I drove the car; no change! A few weeks went by and I drove my 39 Buick to a cars and coffee event at the Petersen car museum. A guy in his later years started looking at my Buick and said that he used to work on these cars at the Buick dealer and I chimed in and told him about the issue. He said there is a certain way to route the wires and further explained that it was a common issue and rerouting the wires would solve the problem. I took the car home and routed the wires the way he had explained and finally reinstalled the cover and went for a drive. By golly the misfire went away and my Buick drove very smooth.

 

1 Has anybody else run into this issue? Did the rerouting of wires solve it?

2 Will ignition wires thicker than 7mm fit through the relief on the spark plug cover?

3 My Buick distributor has been converted to electronic ignition, am I correct in assuming that the wires from won't work correctly and I should buy a wire set that work with a Pertronix modified ignition system?

 

 

Link to comment
Share on other sites
Bloo 25,000+ Points

Bloo

Posted
Posted

Only the spark plug gap and rotor gap will make much difference in the spark voltage, not brand of coil, etc... If only changing the coil, nothing will change. Pertronix makes no difference either if it is installed properly and working properly. Resistance wires, resistor plugs, etc. could have a little effect but probably not much.

 

Buick's hidden wires were always begging for trouble in my opinion. Running plug wires in parallel is a no-no. So is running them along a piece of metal. They mostly got away with it. It's possible taller spark plugs would cause more trouble by pushing the tops closer to the metal.

  • Like 2
Link to comment
Share on other sites
EmTee 25,000+ Points

EmTee

Posted
Posted

My '38 had bare sparkplug terminals when I received it.  I similarly thought I detected occasional misfire.  I did two things: (1) installed 90* sparkplug boots on the wires and (2) installed rubber fuel hose over the sparkplug cover retaining studs that covers the length from the head to the base of the threads.  I then carefully routed the wires under the cover.  So far, so good...  ;)

  • Like 5
Link to comment
Share on other sites
Morgan Wright 10,000+ Points

Morgan Wright

Posted
Posted (edited)

I used Packard 440 wire, it's designed for neon signs of 20,000 volts or higher, outdoors in the rain and ice and snow. It never shorts out even in a rainstorm. 7 mm wire with 3 layers of insulation synthetic rubber inner, then silicone, and a CPE jacket.

 

It has a tinned-copper core, I would never use inductive core wire because I have no idea how they even work.

 

Packard 440 wire hasn't changed in decades because it's the best wire in the world.

 

See the source image

Edited by Morgan Wright (see edit history)
Link to comment
Share on other sites
deac 10,000+ Points

deac

Posted
  • Author
Posted (edited)

This was 7 or 8 years ago. That's why I posted the story because I don't remember. I think he said to route the wires above the spark plugs and make sure they collect or meet inline with the spark plugs and not at the reveal of the cover. It's coming to me as I write this reply.

 

Bob's sells some rubber pieces that's supposed to be used with the wires. However I never bought it because I wasn't sure of how it's supposed to be used. Any suggestions on it's use?

Edited by deac (see edit history)
Link to comment
Share on other sites
dracenroc 1,000+ Points

dracenroc

Posted
Posted

Had the same problem as you. I'm using a converted electronic ignition with a common wire set like available from Bob's. I guess I use the Pertronix coil too but not sure since I changed the system 6 or seven years ago.

I remember I had some trouble with misfiring ignition wires too. As far as I remember the problem was coming from the slot the wires go under the cover. The picture was made quite some time ago and I'm not sure if this was the only spot making trouble.

Not sure if the point identified by the arrow is an additional isolation I added at this time.

 

A lot of "not sure" and "maybes" but I suggest you should check this point too.

If I'm on the car the next time I can have a closer look and come back.

 

 

Monosnap 2022-12-19 22-19-21.png

Link to comment
Share on other sites
Gary W 10,000+ Points

Gary W

Posted
Posted

DSC_0703.thumb.jpg.57f46e28759c4c950c3b92a5cabb0d90.jpg.1c36a9fe3e2c853bbe9fa32841a7d7d1.jpg

I used the 90 degree boots on each plug, made sure to run each wire nice and parallel, trying to avoid them bunching over each other.

 

 

DSC_0715.thumb.JPG.ff0543bb13a58dda7c729710d622a9d7.JPG.8fcceca5f23f4b475027a6f168ffe66a.JPG

There is a small metal clip under the spark cover that should reduce chafing where the wires exit.

And there is just enough room to lay them out evenly

 

 

DSC_0791.thumb.jpg.2419187962643e13978c6cf0683caae9.jpg.61ced66e23dd56f2bc0f85c724c48e7e.jpg

You can see how the wires exit without any upward pressure to chafe against the cover.

 

 

  • Like 11
Link to comment
Share on other sites
EmTee 25,000+ Points

EmTee

Posted
Posted

Gary, thanks for the excellent pictures.  Yours looks just like mine, except I split #1/#2 and #7/#8 by running one over and the other under the cover retaining stud.  Like I said, I put a piece of 5/16" hose on the studs to offer some protection for the wire jacket and get the wire core a little further away from ground potential.

 

I think I also shimmed the metal clip/loop that gathers the wires together to ensure the wires weren't so close that they would chafe on the edge of the pushrod cover.  The sparkplug cover has a rolled edge, so even if a wire touches it shouldn't be cut by the cover.  The edge of the pushrod cover, however, is raw and could eventually saw through the wire jacket.

 

DSC_0715.thumb.JPG.ff0543bb13a58dda7c729

 

  • Like 2
Link to comment
Share on other sites
Mark Shaw 25,000+ Points

Mark Shaw

Posted
Posted

Emtee did a nice job wiring his plugs. 

However, I believe Buick was using black rubber coated plug wires in most straight 8 engines. 

The shorting problem is most often caused by longer plugs when short plugs were no longer available. 

Simply adding a 1/4" gasket to the plug wire cover and/or using 90 degree insulators usually solves the problem.

  • Like 5
Link to comment
Share on other sites
DonMicheletti 10,000+ Points

DonMicheletti

Posted
Posted

The clips are on both ends. I thought they made sense for the longer wires. They keep the longer wires from drooping and being caught under the sparkplug cover.

I am not sure if the wires should go above or below the stud. I thought they made sense on those long end wires,

By the way, that photo above was an "in progress"  shot. The finished wiring is neater.

  • Like 4
Link to comment
Share on other sites
Kenneth Carr 2,500+ Points

Kenneth Carr

Posted
Posted (edited)

I can only comment for 1941. In 1941 the spark plug cables were "covered in black rubber; these wires are not date-coded.

Terminals are zinc-plated with black rubber insulators covering the connection to the wire at the coil and

distributor. There are no insulators at the spark plugs." That quote is from Restoration Facts, 1941 Buick by

William C. Anderson. I use Mr. Anderson's book for any questions I have regarding my 1941 Roadmaster.

Edited by Roadmaster71
spelling error (see edit history)
  • Like 1
Link to comment
Share on other sites
Kenneth Carr 2,500+ Points

Kenneth Carr

Posted
Posted
1 hour ago, drhach said:

I didn't know there was a book like that. I wish there was something for 1942.

Mr. Anderson is on the board of directors for the Buick Heritage Alliance. He may also be an AACA member. If you go to the BHA board page you can click on his name and send him an email. He may have an answer for you.

https://www.buickheritagealliance.org/about/board_members

Link to comment
Share on other sites
Buick35 10,000+ Points

Buick35

Posted
Posted
On 12/22/2022 at 12:35 PM, DonMicheletti said:

Originally there was a "U" shaped clip that fits on the studs to hold the end wires up.

I'm not sure if this is the correct orientation in the photo.

DSCN0139.JPG

I'll have to try to make some my 35s engine. Do you use a spark plug cover as well?

  • Like 1
Link to comment
Share on other sites
Kenneth Carr 2,500+ Points

Kenneth Carr

Posted
Posted (edited)
11 hours ago, Buick35 said:

I'll have to try to make some my 35s engine. Do you use a spark plug cover as well?

That clip looks a lot like the one that holds the sink drain plug lifter to the drain plug shaft that goes out the back of my bathroom sink. It might be easier to make than you think.

Edited by Roadmaster71
posted in wrong place (see edit history)
Link to comment
Share on other sites
deac 10,000+ Points

deac

Posted
  • Author
Posted (edited)

I saw these on Bob's website. I gather they do the same thing as the rubber coated clips pictured above, no?  They want $25.00 for them.....

 

swr390.jpg

1939-1940 Ser 40&60 Buick Spark Plug Wire Retainer Set

 

 

Edited by deac (see edit history)
Link to comment
Share on other sites
Buick35 10,000+ Points

Buick35

Posted
Posted

I had some Adel clamps that I installed.I removed the rubber from the inside of them and opened up the holes a little to get them to fit. I just looked at my 35 shop manual pictures and it doesn't show those clamps,just the lower horizontal one.They're on now anyway..

Link to comment
Share on other sites
  • 2 months later...
EmTee 25,000+ Points

EmTee

Posted
Posted

My '38 didn't have any clips on the cover studs either.  All I did was cut short pieces of 5/16" fuel line to slip over the cover studs so the wire going over it wouldn't rub directly against the stud.  I also installed 90° boots on the wires to prevent any shorts to the cover.

  • Like 2
Link to comment
Share on other sites
kgreen 10,000+ Points

kgreen

Posted
Posted

The two pieces that you show in the photo are for gathering the wires as they enter the spark plug shield.  I'm not sure what the other two pieces are.  A c-shaped, rubber coated metal band was then used in 1940 (your car possibly) at the spark plug cover studs to further gather and organize the wires.  Here's a photo showing the center piece in place.

IMG_2302.jpg.2aed66b3a3252d3d4be17985b291bee1.jpg

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing
×
×
  • Create New...