Exhaust Manifold Study

 Due to the very high price of a new exhaust manifold for the 404, we've decided to see how hard it might be to retrofit a sedan manifold to the UniMoG.  Our current exhaust manifold has a crack... just at the edge of the heat affected zone of a previously welded crack!

Update: Once we got a vacuum fitting (for our brake assist) to fit the new intake manifold, we were able to use the new manifolds that came with our new engine.  This is still an interesting exercise - maybe for a future dual-carb conversion?!?!?!?!



We've welded the crack for now but we're sure it will crack again one day (hopefully far in the future!).  The weld isn't pretty, but it has reasonable penetration & appears to be solid.  With the cab off for painting, it was a good time to weld our existing crack, then pull the manifold to complete the weld and replace the leaky manifold gasket.

With the stock manifold off, the timing was perfect to slip on a junk-yard sedan manifold and take a whole lot of pictures.



Here are several views of the sedan manifold in place on the engine.


This shows how close the manifold comes to the coolant lines.


Frame to bottom ear of front exhaust flange - 185mm.


Frame to top ear of front exhaust flange - 260mm.


Back of generator to top ear of front exhaust flange - 40mm.


Frame to bottom ear of rear exhaust flange - 160mm.


Frame to top ear of rear exhaust flange - 230mm.


Engine block to outside of rear exhaust flange - 200mm.


Engine block to outside of front exhaust flange - 210mm.


Here are some views with the stock 404 manifold back in place:

Frame to front ear of front exhaust flange - 200mm.


Frame to top ear of both exhaust flanges - 210mm.


Frame to rear ear of rear exhaust flange - 180mm.


Block to front ear of front exhaust flange - 180mm.


Block to rear ear of rear exhaust flange - 160mm.


Back of generator to front ear of front exhaust flange - 50mm.
Back of generator to rear ear of rear exhaust flange - 210mm.


View with the cab back in place:

Front exhaust tube to body (top) - 90mm.


Front exhaust flange ear to body (top) - 70mm.


Body to front tube (bottom) - 15mm.


Body to front tube (bottom) - 40mm.
Body to rear tube (bottom) - 50mm.

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