MOPED ARMY

sheet of glass, baking soda and toothpaste mixed, figure 8's and yer done. In like 2 hours.

it will go down evenly if you keep the pressure even and vary the pattern you work the head in. figure 8's, different direction circles, rotating the piece. it's not the space shuttle, dont fret too much.

also I second the emery cloth. its cloth backing will take the oil/lube/whatever without dissolving and buckling like regular sandpaper which isnt designed to get wet.

and... you dont have to do all 0.025 at once. do 0.005 or 0.010 and put it all back together, jet it, and see how it goes.

measuring isnt that hard either. just need a stable reference. have some digital calipers? before you start and as you work put the head down on a part of the glass/marble without anything on it and use the depth measuring part at the end and use the spark plug land as your upper and go through the hole to use the glass/marble as the lower. make sure the glass/marble and the part of the head youre taking down are clean and you will get as accurate as you need.

hope this helps. have fun

I used a mini-mill to mill the head down.. it worked great!

-Naz

Not saying I'd recommend it to anyone but I've used a oiled up cinder block to do the major cutting and then smoothed it out with glass and sand paper.

Has anyone tried this method of of first finding the optimal amount to shave and then trying that? Just curious... I haven't, and actually haven't check my engine yet, guess I will get a cc syringe from a drug store and give it a try, I had someone ask me to cc a engine head anyways so it's probably a good opportunity to do that as well.

The link: http://tinyurl.com/2rqhqv

-Naz

I really don't think you will fuck it up, just go slow and keep even pressure on the head, and rotate it every so often. Thats pretty much it, you can pretty much check it with a straight edge when it's all done to make sure.

-Naz

Also if you take a compression test gage number and divide it by 14.7 you will get the compression ratio. And you can sand it down a lot before it gets too wild. Further, if you want to lower the compression you can add head gaskets or base gaskets. Removing base gasket equals more torque and adding base gaskets mean more RPM.

When you are shaving your head just make sure you have some thin feeler gauges around to check if you have gotten wobbly, if you can shove a .002 gauge under one sealing edge it is time to start thinking of changing strategy because you are making a bit of a wobble head.

If you have a flat top piston that levels up to the top of the cylinder then figuring as you go is as easy as using a syringe of oil and measuring the volume of the head as you shave. Keep in mind that there needs to be squish _area_ so as you shave away the gasket surface you mak have to stop because the squish band is becoming too broad. You can remachine some off to recreate the band but then you would be working backwards as far as compression raising.