vader99

iTrader: (4)

What all is done when someone hand-finishes a set of cnc'd cylinder heads?

Is it just taking out the cnc ridges or is it a little more extensive than that?

GuitsBoy

iTrader: (4)

Usually, its just hand blending everything, and possibly getting any areas the CNC mill couldnt easily reach if it wasnt equipped with a tablet or rocker and the head was bolted flat to the table. Also, many times a CNC program will be set up conservatively to allow for any tiny variations in the casting. Hand finishing lets a person intelligently decide how close to take things.

eamador11

Unless your an expert head porter, you can lose the chamber consistency real fast!

GuitsBoy

iTrader: (4)

True, but i dont think youd want to take the grinder or cartridge roll to the chamber. I small wire wheel followed by a buff will start to shine the chambers up without taking off any material.

vader99

iTrader: (4)

From what I have heard, you don't want to really touch the intake runners at all when hand-finishing, is that right? Smooth up the exhaust good, etc.

GuitsBoy

iTrader: (4)

Well, you could touch them up with a sanding cartridge roll, maybe an 80 grit or so. Most say not to polish the intake runners though. The exhaust runner and combustion chamber can be polished to a mirror finish to keep the carbon from sticking and causing hotspots and to reflect heat back into the cylinder.