[VON]

I need some advice on how to mount a stack exhaust on to the DoKa cab
that I am restoring for my 406. Some of you may have been following my
progress on this post.
http://www.mbnz.org/forums/forums/thread-view.asp?tid=1172064&start=1&fid=35
I am just about ready to prime and paint, so I want to know what I need to
weld onto the cab to hold the stack on. And how others have done it. I don't
want to cause more noise inside with vibrations by doing it the wrong way.
Also do you end up with soot all over the back of the truck with a stack? If
some of you could tell me how you did yours and send some photos that would
be great. My thoughts were to weld some tabs onto the driver's side back
corner of the cab, and then use rubber between the stack and the tabs. Then
use flex pipe to connect the muffler to the stack. I have a 8ft. garage door
so I don't want the stack to be any higher than that. Which puts the stack
at the same height as the cab roof. How hot does the stack get? and how far
from the cab should it be, so as to not burn the paint?
The next thing I need is the measurement between the radiator and the
inside of the grill. Since my truck is all apart I can't get this
measurement. If there is enough room I want to put my AC condenser between
the grill and the radiator. One out of a Porsche 911 will fit the whole
lenght of the front grill, so if there is enough room thats what I plan on
using. I am not putting the hydro set-up back in the truck so I should have
room under the hood for all the AC stuff.
Thanks for all the help! Von

 

[MSD Shop]

Von,
I have done 2 416 doka trucks with a stack, you can usally go to an exhaust shop where they have a bender, I made mine out of 2 pieces of pipe, one from the engine to the muffler and one from the muffler up the stack. You want to BOLT not weld a bracket on the truck, if you ever need to tilt the cab to work on the motor, you would have to cut the exhaust off to do so. Bolt a tab on the rain gutter, use a rubber washer of some sort between the bracket and the cab to cut down on noise. I used 3" pipe for mine and it sounds great. You want your exhaust guy to bend the very top backwards and slash cut it so the exhaust travels straight back when you drive.

 

[MSD Shop]

Also Von, if you are ditching the hyd stuff, I will take it off your hands.[]

 

[esde]

Von, this is what I was planning for the stack on my truck. I am worried that with the flexy 406 frame, if you have the exhaust rigidly bolted to the manifold at one end, and to the body (prob in 2 or more points) that things could get stressed if you flexed it. I'd hate to see a big stack rip free and whack a fresh paint job. I sourced a 3" stack with heat shield, and two 3" stainless braided flex joints from a local truck supply. The stack has spring loaded mounts. I'm worried that they might buzz a bit, but that's for later. I'm kind of on the fence as to keeping the rig style stack cap or not. Pics will follow after figure what color replaces that damn awfull green..... hope that this helps. In short, everything about the truck is made to deal with flex, (including the driver) design your exhaust the same way.... Seth

 

[VON]

Hey, thats looks great! Now how many places is the stack connected to the cab? and I see that you have it on the pass. side. What muffler are you using? I plan on using a Flowmaster 50 series made for SUV's with 3" inlet/outlet. Then a section of SS flex pipe between the stack and the muffler. With the flex pipe I can mount the stack hard to the cab and still have room for the frame twist. If you could take some close up photos of the whole system that would be great!
As for the hydro set-up, its been sold already.
Von

 

[coachgeo]

The PO of my rig built a good stack. NO MUFFLER though. It is attached to the cab via rubber. I assume they are something he scrounged up. He also used a mesh Flex section. This section is directly after the end of the exhast Manifold.

Remember the Mog frame is Ladder and the flex deviates more and more from the twist point in the ladder. (somewhere around the center is usually where the engineer designes the twist point.) Another words there is not near as much flex at the back of the cab or front of the bed as there is at the wheels. That means you dont have a wholle lot of flex to deal with at the common attachement points of a stack exhaust. More than a normal truck but not as much as you might think.