i need help!!!!!!! i am thinking about milling the head .020 and have heard from a few people, no honda's, that it compromises timing belt tension. i would like to do some pistons, but money is an issue so i am stuck with milling or a thinner head gasket. anyone know if this is true?????

 

pluses of milling : cheap way to get compression and increases quench area (aka "mechanical octane boost")

minuses of milling: retards cam timing so you need adjustable cam gears and advancing them 2-3 degrees just to get back to true zero cam timing, weakening of the head deck and possibility of gasket failure.

milling 20 thousandths is acceptably safe. DPR milled my head by 20 thousandths. I did not run into a flapping timing belt problem until I switched to Toda cams 3 years later and used AEM 3 bolt (allen key type) cam gears which may have slipped or the head milling contributed to lack of timing belt tensioner uptake or the Toda B's did not stay at TDC during timing belt installatiion: I never did sort out the source of the belt being off by 2-3 teeth. Needless to say, when pros like Lip report a flapping timing belt with the Todas, it leads me to believe the Todas and milling as a combo are the culprits.

If you have a hankering for more compression, I suggest getting properly sized pistons or using a thinner gasket (which is reversible if you don't like the effect whereas milling is a permanent thing you have to live with like marriage). Some folks deck the block instead of milling the head since there are no structural/gasket failure issues.

cheers

 

My head is milled 20 thousands with itr pistons, I have no problem what so ever.