exactly what is it?? what is done to the heads??

also what is a port and polish and what does it consist of??

 

BASICALLY
the intake and exhaust ports (passages) are rough from original casting and sharp edges
etc. This causes turbulance in the air flow.

Porting removes the rough edges and also refines the smoothness of curves in the passage way.
And in some instances actually enlarges the ports somewhat.
Polishing essentially smooths out the smaller bumps here and there.
The idea is to create a more balanced smoother airflow into and out of the engine.
Is it really worth it for an average rider street machine.... Personally no
but others would disagree.

 

ok thank you and what about a competition valve job does anyone know what that is??????

 

usually a 3 angle cut on the seat and corresponding valve...allows for better sealing.....sometimes the exhaust has a deeper angle cut into it as well

who's heads are you looking at...amatuers can ruin a head easily

 

If I have to cut the metal of my motor.... I pay someone to do it for me! Someone I really trust!

 

Head work is tricky stuff. You want to flow more air but you also want turbulence to suspend the fuel molecules in the air for better combustion. Polishing is kind of a misnomer, you want the air to have an effecient flow path but you want the surface areas of the throttle body andchamber to promote this effect. Which is why it's best to have it done by a reputable shop. That being said there are some great head techs out there. This forum has alot of people runningmod heads. Just search the forums threads and you'll get all kinds of info.

 

i sent my cylinders and heads to NRHS...im getting the 1212 kit with reverse pistons and a COMPETITION VALVE JOB...they guy explained it but i forgot what he said it was.....so i was wondering if someone could explain it to me......thanks for all your posts everyone....i know knothing of machine work i would never even attempt....im a good bike cleaner and i got a lil mechanic skill thats about it.......lol

 

Porting is opening up the passages in the heads soyou can movemore volume of the air/fuel mixtureandexhaust, atafaster rate. The TC heads are choked at the exhaust port and has a smaller exhaust valve then the EVO, part of what makes them run hotter, and right under where both valves seat it is bottle necked. Removing that material and blending the bowl allows more in and more out. It gets into a real scienceconsidering intake velocity, size of valves, profile of cams, ect.and the intended use of the bike is real important in doing the right machine work. Overkill is the biggest mistake most people make. Polishing the exhaust ports benefits extracting the gases but you really do not want to polish the intake port in order to get a real good mix of air/fuel.

 

More to porting, porting aligns the intake and head passages, plus straigtening out the passage. Don't polish intakes. port and polish exhaust to help flow of spent gas.

 

ok so does anyone know what the competition valve job consists of?? or what are the benifits??