Originally Posted by whathaveigotinto
I originally thought my heads had around 72 cc chambers they are phaseII bowties ive learned they hace 64 cc chambers but mine have been milled so they may be less than 60 cc now an i prolly have around 11 to 1 instead of the 9 to 1 i thought i had, i run 93 octane and have never noticed any spark knock i find that hard to believe with steel heads an 11 to 1, i run 36 degree total timing ,maybe my pointers way off ? ,How noticeable is detonation in a loud car turnin 6000 ? next time at the track would it be safe to bump my timing up a lil at a time till until i notice somthing or slow down an not worry about messin somthin up ?
Use the following to determine if the timing tab/mark is accurate:
. Then MAKE A TIMING TAPE
so you can see what the total timing, etc. is w/o needing a dial back timing light- which may or may not be accurate itself.
The problem w/doing track testing to set the timing, is that you really don't know where you are starting at. One run under severe, unheard detonation can ruin an engine- so you need to start at a safe timing setting and work up from there.