port and polish

[knrt03]

i've got a 2002 2.2 eco in my g.a. i am currently rebuilding the head due to a timing chain failure. i was considering taking some time to smooth out and polish up the int. & exh. ports, i am not looking to make the ports any bigger. is this a waste of time or worth the effort for the effect i will receive. also will any reprogramming be needed. i just thought i might as well if i had it out, but i need to know if its really going to do anything from a performance stand point. also considering the same for the throttle body, same question applies. keep in mind this is more of the family car then a v8 killer. but any little hints that will increase performance are welcome. no major mods.

[WhiteSpeed36]

Any time you increase the flow through the engine you are going to yeild a hp increase generally. I would say a mild PNP to the heads would be well worth it as long as you do a good job. Nothing fancy, just smooth it out. You shouldn't need to reprogam anything. The computer will naturally respond to the increase in air. The larger tb will help if you are going to PNP the heads as well.

[ChevelleSSLS6]

hmm, they sell lots of parts for the ecotec.
Do the headwork and then get a shortram style intake and 2.25 inch exhaust with a decent turbo-muffler. Chambered mufflers (think flowmaster) sound really ricey on 4s, I'd go with dynomax or magnaflow, and I'd call it a day then.

It'll be more fun to drive and it wont cost more than $500 total (intake+exhaust)

[knrt03]

good info & good ideas thanks for the input.
keep it coming.

[3100gagt]

heck man u already have the head apart why not slide a set of cams in with gears to compliment!!!!!!!
$600 for the cam's- no need for Reflash or springs.
$350 for the gears (www.mantapart.com)
Then you will have something to back you up.
Then install an SLP cat back $450 i heard they sound nice with the ECO.
Good 20 HP to the ground should get you around town better.

[ChevelleSSLS6]

with the cams and stuff, it starts getting pricey, I'd go for it if it was for a performance ride, but this is a family car also so I doubt he wants to sacrafice much mileage.

Well, with a WAI/CAI and a nice exhaust he'll get both more mpg and power, but cams it's generally more power and less economy. Performance cams sometimes mandate a reprogrammed PCM, which costs money too.

The headwork, I would assume it's all good. What's the stock CR? If it's below 10 get the surface decked a few thousandths to bump it up... the 9.5CR in the 3400 is nice but I think 10:1 would be a lot better. Just make sure you have valve clearance.

[3100gagt]

yea take like 40 thou off the head and hope the valves dont hit
seriously
Get piston to valve clearance and go from there but u will need an adjustable cam gear to get it back in time just to let u know.