[automotivebreth]

I'm new here, looking for information on porting 4 valve heads.
What to watch out for? pictures would be great.

[automotivebreth]

Shon,
I wasn't able to find much about porting the heads here. No worry, I
moving along using normal porting technique.

I broke my torque converter Friday night in the second round so instead
of racing Saturday I worked on the heads. Widened the cross section
as it aproaches the valve slightly and worked the short turn. Tell the
owner he can come here to follow progress, hope to finish next week.

[EagleAutosports]

Sorry about not seeing this earlier, and sorry you never got a response. Looks like you already handled it.

[automotivebreth]

Hi EagleAutosports,
The rectangle port looks rather small, should I increase the size
to better match the oval port?

[GreenSnake]

That would make it worse, in my opinion. My understanding is when using the dual intake port design (one rectangle and one round port on each cylinder), you should stay away from aggressive intake porting. The intake side suffers from too much volume and not enough velocity. If you make the tunnel bigger, you'll amplify the short comings of the design. Matching the ports on the intake manifold->imrc->head might be enough.

Of course, this is an over simplified analysis. Your application may warrant more port work on the intake side.

What are your plans for the engine? blower?

BTW, the rectangle ports are the primary ports. The little notch in the port is where the fuel injector sits. As you can see, the fuel is being sprayed into the primary port ONLY. When you hit 3250 rpms, the intake manifold runner control will open the secondary ports (the oval ports) to allow more air in (I believe the injectors have a longer duration at that point to increase the fuel to match air increase).

[automotivebreth]

Thanks, that’s the type of information I’m looking for. The car well be N/A
street/strip so I will not open the intake ports any more than shown. What
about the exhaust, is the as cast port size OK?

[GreenSnake]

Its believed that opening the exhaust some makes for better flow/scavenging of exhaust.

[automotivebreth]

Thanks Greensnake, I opened up the exhaust a little more than the
intake. Here's a few pictures, Ill get better shots when I get them
polished and cleaned up.