millennium cylinder spark plugs

[ragwingrick]

I have just purchased a gently used pre owned C-145 from one of the members. It has Millennium cylinders. When I pulled #1 cyl spark plug to find TDC for the propeller instlation, I noticed there wasn't a copper washer or a crush gasket between the cyl and spark plug.
All the plugs are the same way. Where could I find the instlation instructions for spark plugs in Mellennium cylinders, I would also like to know the proper torque.
Thanks
Ragwingrick

[Bruce Fenstermacher]

Hmmm. Thinking the seal between a head and spark plug would be a combination of head and spark plug design. In other words not only the head but the plug would have to be designed to run without a gasket. I'm no authority but I've not seen an aviation plug or head designed to be used without a gasket.

I'm thinking these plugs were simply inserted in the cylinders without gaskets to seal the plug hole while the engine was shipped or stored.

[GAHorn]

Torque spark plugs in Continental engines 300-360 in-lbs (25-30 ft lbs).

You can obtain the copper washers from Aircraft Spruce.

Good catch...18mm aviation spark plugs should never be installed without the copper washers.

Since you've caught an obviously amatuerish installation-error... are you certain you have the correct spark plugs for your engine?

[bagarre]

Good segway into re-using the copper gaskets on spark plugs.
I've been told they can be re-used and I've been told they can't be re-used and I've been told they can be re-used if I anneal them each time.
I just bought new gaskets last time to be safe but what does every one else do?

[Bruce Fenstermacher]

Annealing them is easy. EAA has a video showing how to do it. I have a life time supply of Champion Spark Plugs given me with 50 hours on them. I have collected all the gaskets and anneal 30 ro 40 of them at a time.

Annealing them does not "Pop" them out. Squeezing a gasket then heating and cooling them in normal engine operation hardens them. Annealing them softens them again.