[CochinoFilipino]

I'm going to cut open my upper 5.0EFi intake manifold, port it, and weld it back. Anyone have any tips or know of an article on this.
(extrude hone is not in the budget)

 

[lordviper13]

well first off that is aluminum so I hope you know someone who can tig weld, second how are you going to port all the way down the runners, and third I think the when it is welded back together that the jagged edge on the inside isn't going to help you flow out any

how much are you looking to spend because you could probally get a cobra upper and lower for cheap, probally will flow better than the port one anyways and look nicer(no big welds all the way around the plentum)

 

[CochinoFilipino]

I know someone who can weld it and will do it for free. The reason for cutting it open is to access the runners. "jagged edges?" that's why i posted this thread. i need tips on the best way to do this. It's been done before. I think Saleen did this with cobra intakes. someone at stangnet.com did it and had a few tips. I don't want to spend anything. 5.0/AOD conversion, rearend components, rims/tires are eating away at the funds. Thanks

 

[67stang]

Yeah its been done... basically what I've seen is cutting the plenum off with a bandsaw or similar, then port the runners, and weld the plenum back on. The only thing is, the results are very minimal, especially with porting the upper. The reason being the problem with the stock upper is the constriction in the throttle body tunnel due to the two bolts that "pinch" it.

You are better off porting/polishing the lower intake (gasket matching). Even then the dyno results I saw were 10HP peak...not bad for free I suppose.

 

[CochinoFilipino]

I was thinking of somehow eliminating that “pinch” as well. Grind out the pinch, Drill out the bolt holes on top of the manifold large enough for the bolt heads to drop through, Recess the top of the bolt holes at the bottom of the port for the bolt heads. And shorten the bolts. This would elimnate that pinch. I’d use some type of high temperature gasket sealer around the bolts. And some around the top holes under the plate. I haven’t yet completely planned this out. I may have to use allen bolts or something so that I can tighten them correctly.
I also plan to open the #1 and #5 ports on the lower manifold as described in this months MMFF.
I’m still just researching and planning. I won’t have it bench-tested but if it seems successful maybe I’ll post the process on the web somewhere