How far can I go milling the Head?

[Prieto]

On FS engine , how far can I go milling the head? what is the safe point whitout valve clearence or Belt tension problems? Can I shave more than .40 on 93 octanes pump gas?
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[twilightprotege]

why not get HC pistons and be safe?

 

[viVid]

Light Twilight says, I think HC pistons would be the better/safer way to go. The most I have ever shaved was .020". You will need adjustable cam gears to take up the extra "slack" in the timing belt and get the cams zero'd. Also, you may be adversly changing the area/volume of the combustion chamber. Interference may also be a problem with the stock pistons (because they may not be pocketed deep enough for the valves).

I don't exactly know if .040" will give you these problems, but it is certainly things you will need to consider...

 

[twilightprotege]

if you get the 10.4:1 j-spec pistons and the thinnest head gasket (0.021" compared to 0.040" stock) you'll have 10.89:1 compression and you havent even touched the head. not much reason to go higher than that unless you're aiming for massive numbers (read turbo KILLING numbers) like installshield2

 

[Gen1GT]

To actually answer your question, no I'm not sure you could shave your head .40. I'm assuming you meant .040", since .40 is almost 1/2 inch, and would probably chop off the bottom of the valve seats.

And yes, you could shave the head .040" run on pump gas. If you're looking for real power, get HC pistons AND shave the head.

 

[Installshield 2]

Yeah he may have been asking due to head warpage or something....040" should be fine...

Like everyone else said though, its sort of pointless on its own if you are looking for power...you could get like 1whp by itself...but with head milling and ZE pistons you could approach 11:1 compression...and with tuning, thats a decent chunk of power increase...

 

[RyanJayG]

yeah, .040" is fine, but he said .4 I sure hope that was a mistype

 

[Installshield 2]

yeah like Josh said, thats nearly 1/2 an inch...no way...that would definately interfere with belt tension and valve clearances...plus you would have like 15:1 compression...

 

[SpicyMchaggis]

Yeah more re-stating. You really can't go too far, this block is already out there. Just got HC and save yourself the headache. Your welcome to buy my motor if you really want to devote your life to n/a.