jimmyblue

iTrader: (11)

The plastic intake manifold on our cars I believe
is DuPont Zytel nylon. In other places I have seen
reference to "welding enhanced" Zytel (in fact, it
was a DuPont press release having to do with the
6-cyl Trailblazer motor I think). Anyway... many
thermoplastics are weldable using heat or ultrasound.
I know in my area there is a plastic fabricator who
can do plastic welding for build-to-print jobs. And
this is not that big a town.

So I think that this might be a viable option for
the big-throttle-body folks - get the neck built up
with the right Zytel filler, then hog it out to 80mm,
get new captive nuts (or just through-holes) put in,
in the right place, and get a new O-ring seating cut
milled in (or shade-tree it with some plain old
rubber gasket).

If you started from a pre-worked Zytel piece of
sheet stock you could have good planarity etc;
get it milled to fit -around- the stock TB face
external dimensions, weld bead around the back on
a good jig, then hog back the opening and maybe an
inside bead & dress after that.

Somebody with a CNC could turn out proper big-TB
plates on the cheap, get the welding time=money
down to the minimum.