You can type here any text you want

Porting the lower intake - advise?

Welcome!

By registering with us, you'll be able to discuss, share and private message with other members of our community.

SignUp Now!

BuickMike

Money pit
Joined
Jun 7, 2001
Messages
2,792
Any good picture guides on this out there? I'm doing some port matching and want to get some advise before I get too far into it. For example, i noticed that the back side of the port for cylinder #5 would need alot of material removed to be straight with where I ported it to (matching the gasket / Champion Irons). Can I keep removing material until it is flat or should I just let it curve in a little to be safe?

Again, any pics of stock ported lowers would be awesome. Thanks!
 
Porting an intake is pretty straight forward, though time consuming. Goal is to maintain even craoss sectional area in the port, while maintaining proper taper. (contradictory, I know.) Try to keep all ports even in cross sectional area at the same measurement in each port. I.E. .50" in, they all should measure the same, then at .75" in they all are the same, and also at every point up the port. Radius edgeas as generously as you can.

If you are using a Felpro 1200 intake gasket, you WILL break out of a cylinder or two. It's not to worrk if you do, as epoxy will fix it. Prior to porting you can weld up the thin spots, but I hate wleding on a manifold unless it the only way to fix it. Welding on a manifold will usually require milling the flanges flat again. JB Weld is your friend if you break through.

If you are using a stock gaskets (or equivelent) you will be fine. Keep the port walls straight. Remove all the injector boss internally. Remove alot of material on the upper side of the port wall, but remove little on the port floor. I also remove the EGR tower to gain a little plenum volume.
 
The intake only needs a little squaring around the port exits/injector pads and does not need to be ported. It will outflow almost any iron heads with just the light clean up. Polishing is a waste of time. Remove the EGR tower will increase the plenum volume and is worthwhile
 
Thanks for all the advise. My main goal is to match the intake ports to my ports on te Champion irons, which are the same size as the Felpro valley pan. I just figured that flow would be improved if I got rid of that huge step between the ports. I wasn't planning on polishing. Just port matching. I will stay conservative and allow some taper so the inner part of the port has some meat left.

If I remove the EGR tower, do I need to plug the EGR port at the bottom? Do I have to have that welded up with a plate?
 
few pics of mine
 

Attachments

  • photo chars 006.jpg
    photo chars 006.jpg
    41.2 KB · Views: 247
  • photo chars 007.jpg
    photo chars 007.jpg
    32.5 KB · Views: 246
  • photo chars 008.jpg
    photo chars 008.jpg
    34.4 KB · Views: 256
  • runner 011.jpg
    runner 011.jpg
    30.3 KB · Views: 256
Back
Top