Port n Polish

[Nzpure]

Has anyone done a port and polish?
if so notice much improvment if any,im gunna do one got all the stuff at work to do it so ill give it a go see what i get any ideas??

[Philthy]

On an ecotec is it?
I hear people say they have got better economy and a little more power. What else have you done to it?

[immortality]

port and polish woudl go real well with a cam i think. the standard ecotec heads aren't to bad to begin with. a lot better then the older buick heads

[VT-565]

I personally wouldn't 'port' the heads as much as clean them up. Don't forget, you want to polish the exhaust side, but leave the intake side a little rough, to aid in fuel atomization. A lot may argue this, but it's worth taking note of.
The biggest thing would be to keep the flows as even as possible. Are you cleaning up the combustion chambers too?

[Nzpure]

lol not sure how does one do that??
very little knowledge just learning as i go.
father in-law is a holdy nut and he's a mechanic so he's giving me a hand

[ScoHar]

I personally wouldn't 'port' the heads as much as clean them up. Don't forget, you want to polish the exhaust side, but leave the intake side a little rough, to aid in fuel atomization. A lot may argue this, but it's worth taking note of.
The biggest thing would be to keep the flows as even as possible. Are you cleaning up the combustion chambers too?

I agree with this, unless you have a nice flow bench, I wouldn't bother porting them just cleaning them up e.g taking casting marks off etc, your gonna need to take your valves out to do it, so are you also gonna get a valve grind or lap them back in, and all the other bits and pieces that go with that.

Intake rougher than exhaust = great fuel atomization

[Nzpure]

i wanna stroke it too but it cost so much. im tryin to find out size's of rods an pistons an crank grinds to see if i can make one from mostly genuine parts..well what i can pilfer the the techs stashes =D

[immortality]

I personally wouldn't 'port' the heads as much as clean them up. Don't forget, you want to polish the exhaust side, but leave the intake side a little rough, to aid in fuel atomization. A lot may argue this, but it's worth taking note of.
The biggest thing would be to keep the flows as even as possible. Are you cleaning up the combustion chambers too?

i'd polish the combustion chambers. i think what your refering to is normally called pocket porting. mostly just cleaning up the rough casting etc. creating a slight port bias on the intake to help create swirl on the intake vavle also helps fuel atomisation. polishingthe combustion chamber will remove any posible hotspots. helps prevent pre-ingition and help keep the heat in the burnt gasses

[VT-565]

I'd get a spare set from the wreckers and have a go at them, just to get the hang of things. That's how I did it and thats the way to go....
Good luck with it and let us know how you go.

[Nzpure]

if the valves are mishapen then ill grind them an reseat them otherwise ill leave them probly im looking for best performance at the mo seeing how far i can get my commy with out forced induction, i figure if i get my car breathing properly thenwhen it comes to s'cing it or turboing it then the performnce will be better for it

[VT-565]

i'd polish the combustion chambers. i think what your refering to is normally called pocket porting. mostly just cleaning up the rough casting etc. creating a slight port bias on the intake to help create swirl on the intake vavle also helps fuel atomisation. polishingthe combustion chamber will remove any posible hotspots. helps prevent pre-ingition and help keep the heat in the burnt gasses

No, I was talking about de-burring the heads more than anything, removing casting flash etc. Pocket porting is getting into the valve pockets and making changes there, I was referring to cleaning up only.

DIY - Basic Cylinder Head Porting -Standard Abrasives Motor Sports

[immortality]

No, I was talking about de-burring the heads more than anything, removing casting flash etc. Pocket porting is getting into the valve pockets and making changes there, I was referring to cleaning up only.

DIY - Basic Cylinder Head Porting -Standard Abrasives Motor Sports

thats a good article. more of what i was refering to. minimal metal removal. you don't want to remove to much metal and enlarge the ports to much as that only really suits big cams. port velocity is more important on a street engine then large port volumes

[VT-565]

you don't want to remove to much metal and enlarge the ports to much as that only really suits big cams. port velocity is more important on a street engine then large port volumes

Good post. Pretty much sums it all up, however sometimes big cams need a tapered smaller runner, depending on ramp rate. But with the DIY stuff, it's far more effective to get the smaller things right like port matching, stuff that definitely will yield a gain of sorts.