Where ecactly does the GT40 lower need port work?

[Zero Signal]

I was looking at the thing and I didn't see anything that would cause it to be very restrictive like people say. Where is the port work usually done when you guys get them back? Are the runners just opened all around or what?

 

[blksn955.o]

The way Tmoss explained it and showed me the restriction is on the sides walls of the ports. If you take a drop light you can see the runners tapper in on the sides. He pointed out that on the back runners that are the straightest they actually have more restriction as both sides tapper in making it flow less, as the rest mostly have just one side or the other that has the tapper. Make small/even "cuts" to blend the wall to take out the tapper that restricts.

BTW-Tmoss that was still and will allways be in my head what you showed me when you ported mine, thanks for doing it and letting me watch .

 

[homerojr]

I´ve ported mine according to Tmoss instructions. If you tell me how to post pics, I can post some nice pics of the lower manifold, gasket matched to slightly worked AFR165 heads.

 

[tmoss]

blksn955.o - it was my pleasure. The idea is not to take the taper totally out, but to change the taper and particularly to smooth the short side transition to the head flange. opening up the runner on the long side for a larger head runner needs special attention to match the wall transition on that side too. Reshaping the transitions in the bends and making the cross section flow more effective is what it's all about.

 

[Zero Signal]

Ok, kind of what I was thinking. Thanks guys!