Make Your Own Copper Head Gaskets

I was faced with an engine rebuild after I had a crankshaft bearing fail at 45,000 miles. I noticed when I removed the cylinder head that I had a groove from the copper fire ring in the composite gasket that I was using. 

Indent is visible on exhaust (left hand) side

I didn’t want to skim the head because it was flat, and I didn’t want to exacerbate the problem by using another copper ring gasket. After talking to some old timers I came up with another solution: make a copper head gasket.

The main advantage to using a copper gasket is reusability. A copper gasket can be reheated and reused an infinite amount of times. They are also stronger and less likely to suffer a blowout than a composite gasket. Since I’ve blown gaskets in the past I thought it was worth trying.

No one sells copper gaskets for Heinkels, so I made one myself (and you can too). Here's how:

Selecting the Copper: You can’t go to just any store to buy sheets of copper. I needed copper that was about the same thickness as the gasket I had been using. The best source of copper I found was roof flashing from my local lumberyard.  It was available in .030 thickness and widths of 6,8,10,and 12 inches. I decided to purchase a foot-long piece of 10” copper that I could use to make up to 4 gaskets (in case I made an error).

Copper Sheet for Making a Head Gasket

Determining the Design: I had a regular head gasket that I used as a template. I traced the holes onto a piece of thin plywood. 

Using Heinkel Factory Gasket as a Template

Centering Marks for Holes

Then I realized I could cut them all at once by stacking alternating layers of thin plywood and copper. The plywood would prevent (or minimize) tearout of the copper and keep the sheets flat. It would be a more risky approach but would save time,

A copper and plywood sandwich

Alternating layers for the gaskets

I cut the copper with aviation snips and the plywood with a chop saw into 4 corresponding plates, then stacked and attached them.

Cutting the Gasket: Copper is pretty soft but I don’t have metalworking tools. I do have wood working tools, so I decided to use them. If you are going to try this it would be very helpful to have a drill press. I stacked the "sandwich" and then attached the assembly with drywall screws to a piece of plywood, which I then clamped onto my drill press table.

To cut the big hole I used a circle cutter.The circle cutter features an adjustable arm that lets you precisely set the hole size.

Circle cutter mounted in drill press, with assembly clamped to work table

The circle cutter in action on the Heinkel head gaskets

To cut the stud holes I used a 23/64” (.91cm) titanium nitride- coated high speed steel drill bit.

Cutting the stud holes for the gasket

Cutting out the pushrod shafts was going to be a little tricky. I decided to drill out the outline with a small diameter bit and then use a file to smooth out the holes

Trimming the pushrod holes for the Heinkel head gasket

Comparing holes to factory gasket

Once I was done I needed to trim the exterior. For this step I went to the band saw and used a ¼” (6mm) 15 teeth per inch blade. This probably wasn’t the best choice, as the blade was pretty dull by the time I was done.

Trimming the gasket to final shape in the bandsaw

Now it was time to take the sandwich apart and see how I did: Not too bad!

Test fit of Heinkel Gasket

Two of the stud holes were a little tight, so I elongated them with a Dremel. I also had to ease the edges of the cuts. Because I used a saw (rather than a punch like a regular gasket maker would do) I had a tiny edge of copper protruding from the saw kerf. I cleaned this up with a Dremel stone and the basic gasket was done.

Annealing the Gasket: While copper is soft, you should anneal it to make it pliable and reusable. In my mind this is the real benefit of using a copper gasket. The theory is that each time you want to reuse it you anneal it which makes it soft and compressible again.

To anneal the gasket you heat it with a torch until it is red hot, then cool it quickly. I used MAP gas instead of propane, which heated the gasket up quickly.

Annealing the copper  Heinkel head gasket by making it red hot 

Once it was done I dropped it in a bucket of cold water to cool it quickly.

Cooling quickly is the second step of annealing

These gaskets are done, except for cleaning off the soot.

Completed Heinkel copper head gaskets

Installing the gaskets: I installed the gasket using a layer of Hylomar Blue (a non-settting sealer designed for gasket sealing applications).  I torqued it a little higher than the 22 lbs for a normal gasket. The next day I ran a compression test and the engine passed at 120 lbs.

This engine won't be on the road foe some time, so you'll have to wait for a full report. I don't expect any issues. The cost was relatively inexpensive (probably $4.00 each).