polished heads

[ww228king]

what would be the hp gain from polishing the intake and exhaust ports on a 400ex head.....

[EX Stud]

30 horses!!!!!

[ww228king]

lol yeah right .......got any real answers anybody?

[pit/wood]

not much gain from just"polishing"the ports.you dont want to polish the intake port too much,a rough surface promotes the mixing of fuel and air.but you can remove any obsticals to smooth air flow and increase the volume of air allowed thru the port.gets a little tricky here.exhaust ports can be polished.keeps carbon buildup at a minimum.But here also an increase in port size is what you are after,as well as making sure any transitions are smooth(valve seat to port,port to exhaust gasket,gasket to header.to go a little further you can cut down the guides to remove them from the airstream,and on and on.but as far as horsepower gain that can be measured by a seat-of-the-pants dyno.who knows.there is alot of things you can do to make horsepower.