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.

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.

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.

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.

Everything else clears without issue.

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.

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.