High Compression Ratio ----> Detonation

[apardal]

jamiemirror, I'm still going to try those 7 grade spark plugs soon.

robokill, advancing timing is going to wreck the engine. I've been reducing the timing since I started the engine with this CR, and I started it the first time with 13-14º.

Now I ended up with -5º so that it doesn't detonate. Of course I don't make much power with this timing. But the fact that it still does make power, makes me almost sure that the cam timing (mainly the exhaust cam timing) is completely off!

I have already all the tools I need to measure and tune cam timing so that it stays correctly dialed in. After that matter is solved, I'll have some news. Good news, I hope.

Ivan, I already have a wideband O2 sensor to measure the mixture, as I stated before.

Lipinhu, like you, I also don't think is good policy to run the engine with less than 10º of ignition timing. Nevertheless, I need it to run like this so that it doesn't detonate. I don't have the need of such a high compression ratio, but OEM pistons were ruined and I changed pistons with better ones, which elevate the CR. Knowing this, I installed a thicker head gasket of 0.8mm. 12:1 CR is good because I can reach higher levels of power with bigger cams.

And 12:1 isn't that much of a problem. It just needs more care with ignition , fuel and cam timing.

Best regards