What is involved in porting and polishing the head. I figure the polish is a good clean up of the valve chambers etc but what is the porting bit. Just wanted to know

Porting and pol;ishing is basically cleaning up any dags so to speak from shotty factory work smoothing out around the valves to get better flow.....it's all about flow

but u dont want it to be too smooth cause then it probably will run worse than b4, it has to b a little rough for the fuel to flow through, u gotta b good at it. some good power gains out of it though.

there are good gains in gettin a port and polish. ive also found that shaving the head 10 thou also helps. raising the compression helps with fuel economy and also torque. i only got my head shaved 10 thou, but there were still no signs of pinging (wen running on normal unleaded). if i was to do it again, id try 15 or maybe even 20 thou. u may need to run premium or ultimax or something though so that the fuel wont predetonate. (ie, pinging)

this is if ur talking about a 2.6L magna. i dunno how much is enough to shave off a 3.0L or 3.5L etc, or even if u would. the best thing is, it costs $60 to get the head skimmed 10 thou. the price will not rise either if u wanna skim it 15-20 thou. it takes 20 mins to do (though they may have it a whole day cause of other jobs). only costs $60 and that includes the sandblasting :D brand new looking head with higher compression. wat more can u ask for wen ya pay $60.

obviously if u wanna go turbo, dont shave anything off the head. u want lower compression, not higher.

THanks fellas. What exactly is SHAVING the head. What do they do and why do it.

all they do is "shave" a small portion off the bottom of the head. 10 thou = 10 thou of an inch. get a set of feeler gauges and have a look at 10 thou. thats wat they take off the bottom of the head.

this is the theory taken from Fast Fours...

"denser air and fuel mixture in a smaller area means a more instantaneous, bigger bang. you should know what gas does when it gets put into small spaces- it wants to get out. fast, and its this more rapid expansion which causes better power. this, however, comes at a price. you wont be able to run regular unleaded as it will prematurely detonate (also known as knocking, or pinging) due to the bigger compression and hotter running"

Link (http://forums.fastfours.com.au/viewtopic.php?t=84125)

obviously more power for the bang means better economy.

THanks fellas. What exactly is SHAVING the head. What do they do and why do it.Whats the go with stealing my Avatar?:rant:

Thanks. Fordy mate im sorry. Found it on the net one day. Ill change it.