What exactly is done with when the cylinder head is milled? I also remember learning that a certain valve job can raise compression, what is done to the valves to raise compression.

 

heads usually get ported and polished, or shaved...this usually brings back alot of horsepower, or so im told. A shaved head means the surface of the cylinder, where the valves are, are shaved to specs like 20,000 or sometimes 40,000ths of an inch or something, thus making the compression from the pistons to the valves alot closer....increasing HP. I believe this is correct.

 

Head Milling. (verb) The action of removing material form a cylinder head surface, in order to correct head wrapage, and/or increase compression, by means of having lower head to block clearance.

Not an expensive procedure. Not sure how far away Alhambra is from Irvine, but here you go. http://216.239.41.104/search?q...UTF-8

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crono139 &raquo;</TD></TR><TR><TD CLASS="quote">Not an expensive procedure.</TD></TR></TABLE>
yeah it cost me $45 to get mine milled. If you just want something basic done, like getting it milled back flat, open up the phonebook and look up "automotive machine shops"

you may be thinking of a 3 angle valve job. that does not increase compression. nothing you would do to the valves will increase compression.

 

Milling the head to remedy warpage will technically increase the compression ratio by a very small degree. That's becuase when you mill the head, the entire volume of each cylinder is reduced slightly (and I do mean slightly...), but the stroke remains constant. Thus when the piston move up to compress the gas in the cylinder, it's compressing it into a smaller space, hence higher compression. This can be "corrected" by using a different thickness head gasket to make up for the difference if you want to.

 

milling the head can produce 2-3 hp if it's done extremely....but it's mostly a theoretical thing .....typically very cheap to get done though.

- Nathan

 

not worth all that work..to take off the head...and just getting it milled...if you were going all out..lets say a PNP job then go ahead and get it milled.