Here
are some photos of the "Dutra Duals" cast iron exhaust manifolds for
the Chrysler Slant Six. The front manifold is a new iron casting
collecting the front 3 cylinders and has thick walls plus good flow.
The rear section is a modified factory casting.
A closer look at the modified factory manifold I use for
the rear section. This keeps the factory carb. heat riser valve and
the stock automatic choke mounting pockit. You can also re-use your
current exhaust pipe but it is better to have two new header pipes
made and fitted to the new manifold set. The outlet size of both the
manifolds is 2 inch. Here is a good view of the capped-off section
(welded on).
See http://www.slantsix.org/articles/exhaust-man-mods/exhaust-manifold-mods.htm for detailed "how-to" info. on making your own rear manifold section. The major issue I have in making these units up is finding a good factory exhaust manifold to use as a "core".
This
group of photos shows the routing for the new front manifold's
exhaust header pipe. The stock pipe below is hidden.
The
"Dutra Duals" can be used with any intake but there are special needs
for each intake which needs to be addressed.
It is interesting to know that this dual manifold set-up idea
started as a result of "hand fabbed" units. After doing a few sets
this way, ( the "hard way") I went ahead and made-up the casting
equipment to do the front section.
The latest version of the Dutra casting
now has a larger outlet flange and larger mounting tabs. This allows
the unit to be machined for use on the front or rear 3 cylinders. The
large outlet flange is designed to
accept
the mounting of a turbocharger but truth is that doing this takes a
lot of custom work, seeing that the starter motor is in the way.
"Dual Dutra Duals" can also be
done but click here to see some of the issues involved.
Be sure to check-out the Slant Six Message Board and tech. article section at www.slantsix.org
Doug Dutra (Doctor Dodge)