This document summarizes the creation of an ignition coil bracket for an engine. It details the materials used which were sourced from McMaster Carr and includes aluminum, phenolic, and clinch nuts. The bracket was designed to mount the coils to existing valve cover mounts in a way that minimizes modifications to the engine and keeps plug wires as short as possible. Standoffs were welded to a small aluminum plate to support the coils and phenolic spacers were added to prevent binding. The bracket was mocked up on the car where it was found that two plug wires needed custom fitting to work with the new design.

1. Ignition Coil Bracket
Materials Used from McMaster Carr:
1) 1’ length 6061 Aluminum 5/8” OD $9.29
2) Garolite (phenolic) ¾” OD x ¼” ID 40” length $14.58
3) 20 6mmx1 Clinch Style Captive Nut $11.60
4) Various pieces of aluminum from the shop $FREE!
Subtotal $35.47
Tax $2.48
Shipping $6.78
Total $44.73
Engine bay real estate is becoming a valuable commodity as more upgrades
are needed. I wanted to mount the coils in a way that nothing in or on the engine
would have to be modified or moved, they would also need to be kept away from
a heat source as well. I also wanted to make sure the plug wires are as short as
possible. The only viable mounting point was to attach them to existing valve
cover mounts.

2. This led to some interesting stand offs for the coil plate. As seen in the
pictures below, the length of the long side of the standoff is 1.250” and the angle
is 30°. The co-bore is 13/32” and steps to a depth of 1” leaving .250” at the
bottom. The through bore is 15/64” this is clearance for the 6mm valve cover
bolt.
I tried to keep the plate as small as I could since I am only able to pick up two of
the bolts, keeping the bracket small, and strong enough to support the weight of
the four coils was essential. The plate measures 3 5/8” wide x 9 3/8” long with a
simple lay out of the coil mounting points which measure about 2.845”on center.
Instead of tapping the aluminum I used, what I call insert nuts, but, McMaster
Carr refers to them as clinch nuts. Whatever they are called it is much better than
the thin 1/8” aluminum plate trying to hold the threads.

4. I made a quick jig to hold the standoffs in line with the plate, and then tack
welded the mounts to the plate…..the welds are little dirty, but it will do fine for
mock up purposes.
Next, I needed to hold the coils up off of the bracket. It is the way the coil
are made, if I just ran a bolt through the mount the coil wants to be pulled
downward on one side, putting the coil in a bind. This is where the phenolic
comes in. I was able to find ¾” OD with a ¼” ID already made up. All I had to do
was cut off the length at .560”. This holds the coil a touch off the bracket.

5. Now I can mock everything on the car!!
I ran into a small issue at this point. The number one and four coil plug wires are
too short for my comfort. Remember, these wires were off the shelf GM parts, I
was crossing my fingers that I could get everything to fit, but it looks like I will
need to custom fit two of the four plug wires to make it work. This is a very minor
detail though.

6. Everything else clears without issue.

7. Last, I played around with a plate to cover up the ugly spark plug openings. This
plate was an S.O.B. to get right. I do not know how many pieces of aluminum I
scrapped trying to get it to look right, but I finally prevailed…LOL!! The grommets
are off the shelf 3/8” ID x ½” OD that I slit to slip over the plug wires.

8. Next I need to custom make the two plug wires that are too short, and then splice
in the wiring for the trigger, power and ground for the other three cylinders.
Then, I hope to have the dwell control in order to tune for this upgrade.