Straightening a muffler

Nov 14, 2006 8 Replies

I have a Cummins L423D diesel engine that I am trying to slightly fix up.



It has a muffler that was hit from the top sideways (when the engine was being moved on a forklift, I suppose).



Anyway, the muffler attaches to exhaust manifold by means of a diamond shaped flange and two bolts on the far ends of that diamond. (I can make and post pictures on my webpage).



The impact made that flange non-flat, like a "saddle". The thickness of the flange is about 1/4". The deflection is about 3/32" (guesstimate).



I would like to straighten the flange somewhat. I do not have a forge but I have a piece of rail, some assorted 4140 blocks and sledgehammer (3 and 8 lbs, IIRC). I also have a decent TIG welder.



I see two choices:


1) try to straighten the flange by putting it on the rail or flat 4140 block and pounding. (cold)


2) Try to weld a little filler to some areas and then grind the surface to be reasonably flat (should be fine with a gasket).



The muffler's body was also bent a little bit (where the pmuffler's pipe enters its cylindrical main body) but I already fixed that sufficiently to provide clearance for the oil fill cap.



So... any flange straightening suggestions will be gratefully received. I can provide pictures, as I said.



thank you.



i

Cut the flange off the pipe, flatten appropriately with hydraulic press, sledge and backer, etc. then TIG back on to the pipe.

Pete C.

How thick is the flange? If not too thick you could use a hand held O/A torch or even a MAPP or propane torch to heat it to red heat.

dennis in nca

I think that it's a great idea, thanks Pete. Could be the easiest also.

i

I would say it is 1/4" thick and the size is about 3".

i

That was my thought too. That or make a new flange and replace the old one - what ever is easier.

Peter

remove the flange and muffler, turn the flange upside down, put a block under the muffler hole, and pull the ends down with a pair of bolts, or a pair of C clamps etc etc. Id take a piece of scrap, drill and tap holes to match the flange holes and use bolts, myself..shrug

This is far far more controlable than beating on it with a BFH.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Thanks... I will experiment tonight or in a couple of days...

i

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