This is a manifold I am fixing for a friend. He bought it from some clown who has sold this intake where it was modified to be a short runner. His name is Nazty or something like that. Many of the modular mustang guys bought these from this clown and now is no where to be found when the welds started cracking because a too thin of a plate was used. These guys with these Cobras runs some high boost. The one I am fixing was putting out 25psi with a turbo kit. Well the plate is .065" and was acting as a drump and gave up the ghost. So here is what I had to do to fix this thing.
I wanted to cut it off nice and even so I used my JIG plate for the Bridgeport. I had to make some stand offs first so the intake could sit on it pretty level. I used some thick wall square tubing.
Here is the problem,too thin of plate and it acts like a drum and under boost it balloons out and cracks the welds.
Intake set up on the JIG plate on the mill. I had to get pretty creative with the hold downs to clamp it to the JIG plate. I might drill and tap the JIG plate for the next intake for the clamp studs. I did not clamp it really tight as not to warp the manifold.
This is after a couple of passes with the cutter. I only took off about .015" at a time.
Just another pic.
This is after about the 5th or 6th pass, I lost count. You can see the trumpets epoxied on there. I still have to machine some more material off as to get all the weld off. Time for dinner, tomorrow is another day.
Man I have a lot of cleaning to do. Nice expoy huh.
Here are a some issues:
I am still not sure of what to do with the side plates as they are 5052 (.065")material and annealed because there is a bend in one of them so I doubt it is 6061.
I want to heat up the intake in the grille to about 300 degrees and then weld. The reason is that cast aluminum does not like to be shocked with heat in one area, it likes to crack.
However, I do not know if the epoxied trumpets will hold up to the baking.
I am going to make a pattern out of construction paper but I need to cut it out in such a way that edge of the new plate does not match the edge of the intake, the intake material needs to protrude a little more than the plate, this will make for a stronger weld.
