Polishing heads!!!!

[ZOMBIE]

My next stage of modifying!
Basically so far I have done the usual mods [full system and airfilter] however I am still after more power even though the 1300 has more than enough for me to handle. I was told by a mate of mine that polishing out the imperfections that come with mass production out of the head and de-coking the chamber will see a noticable increase in power.
Has anyone done this before as I have no real knolledge about this, also I have heard that in some cases you can actually loose power?
Any feedback would be greatly appreciated, Thanks

[mk2keel]

I have decoked all of my engine inside, it can in bad cases cause you to lose power and i was just hoping to gain any that i might have lost through it coking up. Basically the shinyer you make the metal inside the better, although i wouldnt touch the bores because you could end up with all sorts of problems (they dont really coke anyway). If you polish up the piston and the bottom of the head including the valves this should stop any power loss and it will also stop it from coking up again (car manufacturers dont bother making it shiny so that is why it is allowed to coke)
I dont think you could gain power from it, at least i doubt you can might be wrong though.

[Tahrey1043]

you do in gran turismo

[GroovyCarrot]

Well, you can gain power from it, but it really needs to be done in conjunction with derestricted inlet and exhaust manifolds, performance camshaft and all that jazz, I doubt you'll see much of an improvement on it's own. Also, I'd suggest that decoking the engine is going to be a waste of time unless you've got quite a serious problem that's really choking it up with carbon, in which case I'd advise sorting that problem first and then cleaning it out or else it'll just build up again right away.

[minis84]

I have heard that making your inlet ports and chambers TOO shiny (polished) makes it worse, because the fuel and air mixture hitting the 'imperfections' in the head cause eddy's and swirls in the mixture, helping more to get into the combustion chamber. If you make it too polished, the mixture just 'pools' around in the head, and doesn't always reach the chambers as it should, and maybe not at the right velocity, meaning it can't exit after combustion.

Like GroovyCarrot says, its always best to do mod's like that in conjunction with a performance cam, and inlet and exhaust manifolds uprated. It is in fact one of the last mods you should be thinking about, as really the secret of power is to just get more mixture into your engine, and more exhaust out, faster. Hence high lift/longer duration camshafts, and uprated inlet/exhaust manifolds.

Tom

[hardhitter]

Yes, when porting/polishing a head you are not actually polishing to a smooth mirror finish as this can hurt performace. A slighty rough texture helps keep air/fuel mix together and prevents fuel puddling in the ports. You are aiming to remove roungh casting marks, flashing and anything the is restricting air flow. The key is to remove material in the right places.

[minis84]

nice signature hardhitter!

[k4lps]

do a serch on google theres plenty of diy guides out there

[D4V1D]

get it done by high flow heads.
they do stages to suit how much money u got and they can enlarge ports for you as well, gaining some performance

[k4lps]

Yes, when porting/polishing a head you are not actually polishing to a smooth mirror finish as this can hurt performace. A slighty rough texture helps keep air/fuel mix together and prevents fuel puddling in the ports. You are aiming to remove roungh casting marks, flashing and anything the is restricting air flow. The key is to remove material in the right places.

only on the inlet u can have a mirror finnish on the chambers an zorst ports i think