If you ride a Pan or a Shovelhead youíre
probably tired of exhaust leaks or pipes that wonít stay on the heads,
Panhead spigots always wearing out, and clamps that wonít tighten up.
These problems always seems to happen at
the wrong time or place. Shovelheads eventually strip their threads and
helicoils donít help for long.
If you want a temporary solution we can
replace Panhead spigots with 6061 aluminum alloy, if you want to keep
the stock look. Or try the Shovelhead fix with an 1 3/4" long stud
buried up in the casting.
After doing a few hundred of these over
the years, we decided to come up with a permanent solution to these
exhausting Pan and Shovel problems.
We had seen some poor attempts at welding
flanges on Shovelheads using three bolts. So we thought, why not make
some flanges out of really good aluminum and regular automotive header
We started talking to people about it and
the next thing you know it was actually happening. A couple more months
of work and we had one really nice flange kit.
Our aluminum alloy flanges are top
quality: cast from 356-grade material and hardened for maximum strength
and weldability. The steel and aluminum flanges are matched and machined
together for a more precise fit. They will fit together only one way and
are marked on one side with a blue line. These puppies will last until
hell freezes over.
Our 3-Bolt Exhaust Flange Kit will fit
both Panhead and Shovelhead engines.
Shovelhead exhaust pipes work well on
both models. Welding them on your heads can be tricky but a good welder
that is experienced in welding H-D castings should have no problem. Or
we can do the job for you.
If you want to do install the kit
yourself, no problem! We have put together six pages of installation
instructions with three pages of photos to make sure you get it right
the first time.
Following are excerpts from the
instructions for the Panhead installation of the 3-Bolt Exhaust Flange
Kit, to give you a basic understanding about the procedure. If youíve
got a Shovelhead, the preparations are identical except that there are
no spigots to remove.
1. Heads must be clean and free of oil and carbon especially in the
area to be welded. Remove existing spigots with a hacksaw. A disc
grinder can be used to finish the cut cleanly. With the grinder
the casting approximately 1/2-inch into the port. At a 45-degree angle,
grind a 1/8-inch area at the edge of the inside of the port for welding.
The next step requires a short, straight
piece of pipe, 1 ĺ inch by approximately 4 inches long.
2. Now take one flange assembly and line it up on the head, then
insert the short pipe and hammer it in slightly. It will hold the flange
3. Check to be sure that the flange is flush against the head. The
flange should rotate freely on the pipe. The location of each flange is
important. Using a square on the rear head, line up the flange at 90
degrees to the head surface with the blue line on the 90-degree side of
4. Before welding, all areas to be welded should be roughed with a
grinder, especially if the head has been glass-beaded. A short area on
each flat side of the alloy flange must be welded first.
5. Tack one side securely and check to be sure the flange is flush
with the head. It may be necessary to use a hammer to make adjustments
before completion of all three tacks.
6. Now remove the short pipe and the steel flange and you are ready
to finish welding.
Our instructions recommend 200-plus amps
for adequate penetration. The puddle should be approx. 1/2-inch wide on
the inside of the flange and 1/4inch wide on each flat side of the
7. After the welds cool (naturally) it may be polished lightly.
8. Location of the flange on the front head is done with the square.
Line the square up across the valve guide holes and the flange parallel
to the head surface with the blue line against the square.
Our instructions go on to explain some
minor clearance needed for the cylinders and exhaust pipe installation
for both pans and shovels. A three-point mount is necessary on both
exhaust pipes to insure against vibration damage.
Our 3-Bolt Exhaust Flange Kit isnít a
quick or temporary fix. The end result is an awesome exhaust manifold
system. It works great and is guaranteed to hold for years to come.
For further info contact the FLO
Headworks customer service hotline, 805-481-6300.