Want to port myintake manifold, how much do i need to port? whats the specific diameter?

 

as big as the gasket hole.. any bigger you will ruin the head


the exhaust port is a tad different... you can add 2mm yet you will need to polish the hell out of that side.. mirror like to give an example....

 

thanks bro. looking foward to do it

 

You should polish the exhaust very well and a bit the intake. There are different theories about it but I would still polish it slightly to increase air flow. And don't go larger than the gaskets.

 

Yep, what PR MIVEC said, go as big as the gasket, but make sure you dont go bigger than the head ports, or you will create a... (ESCALON) and that will ruin the flow. You can also port the throttle side of the intake manifold, and add a Eclipse 3.8L throttle body (5mm bigger than the Ralliart) and its PLUG & PLAY

 

thank guys that will be my next mod.

 

did I mention anywhere on EVOm that im selling a 3.8L Eclipse throttle??

hehehehe

Goodluck man

 

I know it could sounds like an newbie question,but...

I want to port/polish my intake manifold too.
I know i Have to grind not much than the gasket.

My question is
How long in the hole i have to grind ? ( the arrow on the left on the picture)

Do I need to grind something else than the fours cylinder tube ? I know i can do the Tb too, but i won't touch to that... Will I feel gain if I only do the four tube ?

Thanks

 

for the exhaust header, a ceramic coat works well

 

as far as you can reach and still keep it nice and smooth. you don't want any jagged edges, so don't worry too much about it. making that transition into the head smooth is important, so don't make the holes bigger than the gasket unless you are porting the head too(and getting a bigger gasket)

 

Thanks Dan, I'll do the job as soon as I get time to do it. I'll post pic for sure...

 

You do NOT want to polish it. Intake air flows the best through a rough surface to go into the head.

 

HUmm, from what I thought, air flow is better when the surface is smooth... no ? So i've to port the IM but do I need to polish it a lot to make it smooth? just a little bit to let it a little rough or just let it rough completly (erase big marks that all) ?

 

You want there to be a slightly rough surface to it. Similar to say a 200 grit sand paper as an idea.

 

+1, polish is for exhaust side. my remark was to keep you away from gouging the runner all to hell. hopefully no one confused smooth with polished, but if you did there is a big difference.