carbon deposits on valves and tops of pistons

i'm in the middle of doing my headgaskets. when i pulled the heads off there were flaky carbon deposits on the bottoms of the valves and the heads and also on the pistons. the car doesn't knock or ping and appears to be running very strong b4 the HGs blew. i always use 91 or higher octane though i don't know about the previous owners. i have been using autolite double plat. plugs with the factory recommended gap. are these deposits normal? what could be causing them? thanks for any info

of course deposits are normal, if they werent there then people wouldnt worry about smoging their cars. just like u would find deposits on the tail pipes they are very very common. no matter what type of gasoline u use.

Its caused by unburn fuel. You will never be rid of it as there is no engine in the world that is 100% efficient.

Shane

Jeremy, I also am in middle of HG job. I have carbon built up on valves, but pistons seem very clean. I drive hard though, but the dang amount of burnt oil all over the inside of the intake manifold is what concerns me. How's yours? Think mine is coming from PVC Valves letting in oil to intake system.

Not to bad of a job once you get all the junk off the top/front of the engine..

BobGPz said:

Jeremy, I also am in middle of HG job. I have carbon built up on valves, but pistons seem very clean. I drive hard though, but the dang amount of burnt oil all over the inside of the intake manifold is what concerns me. How's yours? Think mine is coming from PVC Valves letting in oil to intake system.

Not to bad of a job once you get all the junk off the top/front of the engine..

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mine was pretty much steam cleaned inside. i had coolant sitting in my intake manifold. i had 1 clean piston where the HG blew. the others look to have just light carbon on them.