Wanted: pictures of combustion chambers at teardown

[jpnovak]

For some strange reason yet to be realized I am curious about the burn patterns in cylinder heads. I want to open up my thoughts to all of you for input. This is meant to be a good conversation topic where we all learn something.

I would like to see how the burn pattern is affected by different dome shapes and volumes. For example, we all know a CIS piston has a squish zone that is supposed to concentrate the air/fuel charge at the spark plug. Another example would be the early 2.0l engines that nearly require twin plug at higher compression due to chamber splitting.

Does this mean that the back of the dome is shielded from the flame front? Can this be seen by a non-uniformity in the carbon coating opposite the spark plug? I am pretty sure it does. Let's let the pictures tell their 1000 words.

Please post pictures of the cylinder heads and combustion chambers as they are removed from the engine. It would be helpful to name your injection system (although its pretty easy to tell from the dome type), compression ratio, engine bore, single/twin plug and approximate mileage. Also indicate if the picture is of a damaged cylinder (i.e. headstud, valve guide or other issue).

I will continue my thoughts and discussion once we have visual aids. Thanks.

[Aurel]

Here are three out of my 78 3.0SC CIS SC cams, 8.5:1 CR, 110,000 miles, featuring leaks caused by broken head studs.

Aurel

[euro911sc]

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Enjoy!

-Michael