I am considering getting a little bit of work done on my oz at the local machine shop, specifically port and polish. What kind of gains could i be looking at with this and are there any extra things i have to do after such as better gas?

 

REad this thread thoroughly.

https://www.evolutionm.net/forums/sh...d.php?t=101012

All of what you are asking is discussed there.

WADAD

 

i read that b4 posting im not talking about the kit im talking about just the port and polish from a local shop, do u think this is even worth it, is their anything major i need b4 this.

 

Well Ok if you HAVE read the thread then refer to this page and posts #'d 63-64.

https://www.evolutionm.net/forums/sh...2&page=5&pp=15

If this doesn't HELP you then sorry for wasting your time!!!

WADAD

 

Wadad beat me to it. The Bullfrog thread goes over the benefits (and lack of without other major mods) of porting and polishing. Bottom line is that it's not very cost effective until you have more hp/tq to begin with.

 

My brief discussions with Dave at RPW lead me to believe that a cylinder head porting will yield about 10HP. Dave says about 10% gain on the 4G family of engines. My own experience with the intake manifold gasket-matching port will yield about 10 as well.

We'll see though. ported cylinder head is my next project I'll be lapping the valves to get rid of any carbon, but I won't be polishing anything.