question for machinists/performance minded ppl

[rurouni20xx]

well i have a leaking head gasket (or so i hope im losing antifreeze and you can smell it from the exhaust, no physical leaks) and am looking into getting another head installing a cam/valves/porting/shaving it for a lil more umph since i have the head off anyway. looking into the compupro stage 2 or 3 crower cam with matching lifters/springs retainers, and oversize valves/bronze guides/viton seals. the real question for you guys, how far down do you shave the head to achieve 11:1 compression? its a 92 ford ranger 2.3 8 plug head with hyd roller rockers, im keeping the hydraulic roller rocker setup. found a few headgaskets, would like to go with a .040 inch headgasket but if needbe i found a .032 compressed thickness gasket. any and all input on what i want to try and do will be greatly appreciated. also if anybody has a used head they would like to sell (sticking with the 8 plug head for use with the factory ignition system.) ill gladly look at it.

 

[BogusSVO]

with the piston in the hole .015 and -3 cc valve relifes, and a gasket thickness of .041
you will need a head cc of 49 for 10.08:1, 46 for 10.5:1, 43 for 11.03:1

with the .032 HG you will need a head cc of 51 for 10.08,47.5 for 10.57:1 ,44.75 for 11.04:1

with a cast iron head and 93 octane gas , you should stay at about 10:1 more than that and you will have to pull ignition time to stay out of pre det.

you generally close the combustion chamber up 1cc for every .008 milled off

 

[rurouni20xx]

so how far off is that? thx for replying btw.

 

[BogusSVO]

well the head will need to be cc'ed so you have your start point.

http://www.therangerstation.com/forums/showthread.php?t=75067

then once you know how many CC's your head is, then you can figure out how much needs to be milled

 

[rurouni20xx]

i understand was just wondering if somebody had done it and how far they had to go so i have a rough estimate of how much needs to come off. i have that layout in my engine blueprinting book altho they say do it a lil differently. ill look at it again and post how they say to do it, i believe it involves modeling clay, you can also do this when bench building to check your piston to valve clearance.

 

[BogusSVO]

due to the variance in the castings the only way is to cc.

yes I know about claying the tops of pistons, but unless you make a mold of the combustion chamber then submrge the clay in water.... I do not see how that will work