I have a 77 Spitfire with a Weber DGAV down draft carb. It had its
original exhaust manifold w/catalytic converter attached. One of the
studs holding the catalytic to the exhaust manifold fell out and it looked
like a pain to fix it, so I decided to put on a header and get rid of the
catalytic converter. I bought a monza header from TRF. First off, the
pipes and the flange aren't flush. I figured this shouldn't be a problem
since the pipes protruded a little and seemed to fully cover the exhaust
ports on the head. However, after installing the header, I'm not getting
a good seal and have exhaust blowing out around the head. Does anyone
else have experience with these headers. Do I need to grind them down?
A few notes to others about these headers. They were very hard to get in.
I had to jack up the front end. Then undo the engine mounts and jack up
the engine. Only then could I get the headers in coming from underneath.
The fitting problem is due to the 4 into 1 design. It creates such a big
bulge point, it can't fit between the engine and the frame. Also, once
installed I'd say there is no more than 1/8 inch clearance between the
bulge point on the header and the oil pan. I hope that this doesn't cause
a heat problem. I don't want to heat the oil up anymore than it already
is. Also, the exhaust pipe doesn't fit as nicely as I would have liked.
If I had to do it over again, I'd get a shop to frabicate a new pipe to
replace the catalytic converter and use the old exhaust manifold. This
was actually recommended to me by someone on the list, but I had already
purchased the header.
Now to the intake manifold. It seems that only the top 4 stud/nut combos
support the weber intake manifold. When I took it apart, I noticed that
whoever installed the weber had put a couple of long hex nuts on the inner
lower head studs and let the intake manifold rest against these. I assume
this was done for support. This manifold has a water pipe running through
it. It takes in water from the themostat area and just passes it through
to the other side of the manifold where it goes into piping which
circulates it through the carb. The carb has a water activated automatic
choke. Well, I think the hex nuts used for support have worn a hole
through the pipe. I have water practically gushing out. I thought it was
the old hose at first, but replaced that and now I'm pretty sure its a
hole in the intake manifold. I plan on just bypassing the pipe in the
manifold with a longer piece of tube. Will this cause a problem? What
is the point of running the water through the intake manifold? Does this
heat up the manifold and help in cold weather or something?
Also, does the intake manifold need extra support? It seems like a lot of
metal just hanging off the side of the engine.
Thanks for reading the lengthy post,