port and polish

[whowhatwhere]

haha yeah
i ported the exhaust side of the head, and made it all smooth:)

It looks like you did 1 inch of the exhaust port.

And its all dirty. Remember, A clean engine is a happy engine. And it dosent get you dirty when you work on it

[85Ecoupe]

haha yeah
i ported the exhaust side of the head, and made it all smooth:)

oh and heres a pic of my block

[E30Idea]

unless you plan on revving to 7+ grand all the time.

And we all know eta's dont do that ...lol

[Sean]

Put in higher duration cam - or a cam that opens the valves more. 3-angle valve grind that reseals the valve seats. Port matching.

I'm sure there's more, but titanium valves and fancy head internals really aren't any good unless you plan on revving to 7+ grand all the time.

[85Ecoupe]

what way can i improve the head without swaping it??or is there a head likt the super eta that is a direct replacement?

[85Ecoupe]

can someone give me a price for valves, springs(better than stock) retainers, etc......????
maybe a cam too:0
oh and metric blues

[nando]

you want to polish the exhaust, because the only thing that matters there is airflow. on the intake a rough but smooth surface will do. also, polishing the combustion chambers is a good idea, but be careful not to remove a lot of material as you will change the compression ratio and each cylinder might be different..

[E30Idea]

Well played, Now this is a good r3v thread. I am learning with constructive feedback. Really, Thanks you guys. I was about a week or so from going nuts with a dremmel on anything that I could port or polish on the intake. Thanks again.

[Sean]

because fuel will end up sticking to the walls of the port rather than mixing with the air. you want a smooth surface with no sharp points but the surface itself needs to be able to create turbulence in the airflow so the air and fuel can mix properly.

Yea if it's smooth, the fuel will not mix correctly.

[nando]

Why? I honestly dont know... But I would figure that a smother more free flowing anything on a motor would be a bonus. I dont know, I am willing to be wrong.

because fuel will end up sticking to the walls of the port rather than mixing with the air. you want a smooth surface with no sharp points but the surface itself needs to be able to create turbulence in the airflow so the air and fuel can mix properly.

[PiercedE30]

Why? I honestly dont know... But I would figure that a smother more free flowing anything on a motor would be a bonus. I dont know, I am willing to be wrong.

Best description that I have ever found to explain it:

Surface Air Flow
As air moves over a smooth surface, the thin layer of air having direct contact with the surface is nearly dormant (barely moving). Why? This layer is clinging because of surface tension. The clinging is disrupted by any increase of movement created in that first layer. Movement in the successive layers is enhanced since they are then "riding" on an already rolling foundation.

Smooth Surface
Air flowing over a rough surface is greatest simply because the air contacts “touch" the entire surface and this causes maximum resistance.

Rough Surface
Air flowing over a rough surface "touches" mainly the high points. This sets up a stumbling action at the surface disrupting the dormant layer and generating a slight flow increase.

Sculpted Surface
A sculpted surface is one with a repetitive pattern specifically designed to generate rhythmic air turbulence at its surface for maximum air flow. It's the basis for the Surface Turbulence in our Engines and Heads.

[E30Idea]

generally it's a bad idea to polish the intake side...

Why? I honestly dont know... But I would figure that a smother more free flowing anything on a motor would be a bonus. I dont know, I am willing to be wrong.

[85Ecoupe]

that would be awesome, mine is down right now i took the head off And im gonna ask cheshier to port/polish it or get some one else to :)
and it was hella dirty (the motor)so im cleaning it up

[asubimmer]

cool deal. We really should have a Boone e30 meet soon. There are a lot up here now it seems.

[85Ecoupe]

yeah Charlie, its jimmy