i was brainstorming at school today about porting my intake manifold.but i couldnt think of any way i could port the upper intake where it has a 90degree turn then i had a stoke of genius (im sure someone else has done it b4).i was wondering if anyone has anyone cut a cross section of the intake manifold,ported all 4 ports and then welded it back together (and ground down the welds for that stock look).

if no one else has done itb4 i want all ownership of the process.it will be called CPW,for cut,port,and weld.i want ownership over it like that guy did with the supras and BPU J/K LOL

 

uh how else you think it is ported... except for extrude hone. its a common way of doing it, hell i have seen old school racers do it for years. the tricky part is welding it back together. If the manifold is cast good luck!!

 

I think I remember that Rotarygod here on the forums has done this; Rotarygod is also in Houston...

 

Section!

 

why not just make a custom inlet and tune it to your needs?

 

why dont u make on and tune it to my needs....j/k

i dont have the engineering background to design my own intake manifold

 

lol....if u do a search we talked about this in a thread started by me....i also considered cutting and rewelding but supposedly it's a pain in the *** to weld back cast aluminum....iunno why....ur better of extrude honing it

 

I've cut every different style of RX-7 manifold apart, ported them, and put them back together. It's an awful lot of work.

 

I Know welding cast IRON is a PITA, but I had not heard that about cast aluminium.

 

go to NW and check out gambone he has a custom intake that willgive any body wood

 

I'm doing m own inlet when I rebuild my 12a, I've never ported an engine, taken one apart, or done any modifications to one. But I'm very technically minded, read as much as I could - but it's the reading that gives most of the know-how you'll need.

here's the thread on calculating your ideal runner length https://www.rx7club.com/showthread.p...hreadid=199788
enjoy

 

Much of that thread was a big debate and it turned out that both of us were arguing about 2 entirely different but related intake phenomena. That formula is a shortcut to avoid a few other steps. It still gets extremely close.

 

well, after the first page, i just stopped reading anyway (i got what i needed!)

 

cast aluminum is very easy to weld, it's catching the micro holes that's a PITA, I use a harmonic table to weld it and I've never had a micro leak..

 

Right then - I've only just realised something.

When you do that equation, do you make the measurement for the final length, from the exterior of the block - or from the port itself?

Oh yeah, and where do you measure the angles for the ports from? I'm making a PP, so I cant use any standard measurements

 

Nice try, though!

You can see the weld at the start of the runners.