Polished Heads

[rpromero]

Has anyone done this yet? Is it worth the investment?

[TLS2000]

No one has done it that I'm aware of. If you're willing to do it, I'd like to know the results (Dyno before and after).

[G6Performance]

I haven't seen the heads off the 3500 or 3900 yet, but good headwork on the older version of this (3400) gave some great results. I'd imagine you would see 8-10 across the entire RPM band. You may need to bump the fuel pressure to keep up.

[hnda8n]

I dont know about the G6 but when I had my Toyota, I had it port and polished, and whoa what a difference . Im not to sure of the gains, but you could def tell. Im sure if you do it to your 6er you will see the same results.

[disposablehero]

Just do it and let us know.

[TLS2000]

Yup, anything that'll help the car breathe better will have good results.

[bristol16]

Yup, anything that'll help the car breathe better will have good results.

electric supercharger?

[beitodesstrafe]

Yup, anything that'll help the car breathe better will have good results.

electric supercharger?

+ a tornado = almost as much power gain as a type R badge and a foot high wing!

[Blackrider]

I can see a ported top end giving some pretty good gains on the 3900 and 3500, it sure did on my Grand Am. BUT notice I said "Top End" just doing the heads is NOT worth it, do it all well its ripped apart Ported Upper and lower intake manifolds, ported heads, valve job ect. If you get really crazy some new SS Valves, SI will make you some for 12 dollars a valve.

I can see myself doing this in the future but not before headers.

Milling the heads is also an option, milling is shaving material off the bottom of the heads which brings them closer to the block when installed bumping up to compression ratio, but we're talking .020 and an increase of compression somewhere in the .4 - .5 range, it does wonders for low end torque. I doubt I would go this route on the 3900 due to the fact that is already running 9.8.

[hnda8n]

Whoa thats just too dam technical for me.

[TLS2000]

That's very technical to me too. What kind of cost would we be looking at for that Jordie?

[bristol16]

i agree you would want to port match the intake and exhaust manifolds to match the heads....the intake especially. i don't particularly like milling heads; i think there are better ways of achieving a higher compression ratio, but whatever works i guess. i know some people use a thinner head gasket on top of milling the head to close the gap even more. i would consider this only if i were dead set against doing bottom end work, but that is also a much more expensive road to take.

[rpromero]

THanks for all of the knowledge. I don't have anywhere near me with a Dyno to get true tuning and results. I'll check and see what I can get the whole thing done for and keep everyone posted if I decide to do it.

[ElecBlueG6GT]

i agree you would want to port match the intake and exhaust manifolds to match the heads....the intake especially. i don't particularly like milling heads; i think there are better ways of achieving a higher compression ratio, but whatever works i guess. i know some people use a thinner head gasket on top of milling the head to close the gap even more. i would consider this only if i were dead set against doing bottom end work, but that is also a much more expensive road to take.

I would want to know the valve to piston clearance before I attemped this. I think I would prefer a more agressive cam and better valve train components, along with porting.

[dre256]

Polishing the heads you will notice a big pick up, but honestly if your going to remove the head do what Blackrider suggests with the valves because if your going to take the heads off, might as well spend the extra few dollars and get it done all at once. I dont know if we have rocker arms or roller rockers but you can change them out too if your looking for top end, becuase a biger rocker number will drop the low end a little and also raise the piston clearnce closer. Also What Blackrider sugests with the milling of the head is a good idea if looking for a lil more compression like he said, higher compression is generally better gas millage but if you do mill the head and raise the compersion and you ever boost your motor you will have to take the head off again because then you def be putting out to much compresstion for a turbo or supercharger and need to drop the compression for forced introduction or you will rip your motor apart in the first 5K milles.

Overall to ansewer your question is it worth it, yes and no...... Yes if you your going to take the head off your self and save on labor and No in my oppion if you pay some one to take off the head because a normal mechanic eat up alot of money in labor removing the heads then better to get exhaust, CAI, maybe get you fuel injectors syencrotized and bored .05 over but no more than .05 on a stock motor esp with no forced introduction.

Thats just my oppion