pdd

iTrader: (3)

i put in my tr224. so the mext step would be heads, but with mass's tight emissions law, have no idea if id pass

Tin Indian

won't hurt at all

deviate42

iTrader: (2)

Like tin said

it shouldnt make any difference

MrYenko

Im thinkin that if you passed already with your cam, emmissions might actually get BETTER with ported heads, because its breathing more efficiently.

BurnOut

iTrader: (1)

Difficult to say, really; depending on how emissions are measured.

For instance, it could be that with even the best ported heads, there may be some loss of port velocity at low speeds, which would result in a poor(er) cylinder fill (at idle), which would in turn result in a rich mixture.

Or, I could be completely wrong; just something to consider, is all.

DONAIMIAN

iTrader: (18)

I could see the test results improving with heads. Because of the whole efficency thing.

pdd

iTrader: (3)

thanks for the replies, maybe i smell a winter time project coming up

Ferocity02

iTrader: (60)

Yep, I always heard they improve emmisions, by allowing the complete combustion of the fuel and air, a big cam could screw you up though

pekkaz

Variations from port to port cause the fuel mixture to vary from cylinder to cylinder. That can ruin the emissions. Quality of the heads is very important.

LS1derfull

If heads raise compression than NoX emissions can be higher, good tuning that is usually needed for heads cam should keep motor somewhat clean. Biggest problem is loss of cats or rear placement of aftermarket cats, they dont light off as well further back from motor. They are what cleanse the exhaust of most of the pollutants.