Has anyone found a muffler for an OC-3 in a tractor store that fits without much modification. I have read that a 1.5" O.D. inlet goes inside the exhaust manifold outlet. My Oliver exhaust manifold also has a lip on the outside that is 1 7/8". I found an ac-1 (ALLIS) muffler that would work well but it is just a little large on the inlet and I'd prefer to have it clamp to the O.D. of the exhaust manifold outlet (1 7/8"). The inlet length is 7" which would be just right. Before I start welding up an adapter, is there anyone that has found an easy to fit muffler.
Thanks
Hi Glen -
Couldn't find one, so welded one up from 1/16 steel plate. It's been 30 years, and still working. The originals lasted maybe 10 years.... It wasn't fun plowing snow and breathing the exhaust blowing out from under the hood...
Started with correct size exhaust pipe to fit outside the manifold. Cut it about 3 1/2" below the top of the hood, welded a stop plate, then rejoined the cut-off part to make the "tailpipe".
Drilled a bunch of 1/4" holes (30?) around the pipe for 2" or so both sides of the weld, to let exhaust gas into the muffler, then out the stack above the splice. It's important that there's lots of area in the holes - probably 50% more than the area of the outlet in the manifold. I'm told that a restriction here can result in burned exhaust valves.
Then shaped a 6" or so strip 8" or so in diameter (squashed a bit, and of course off-center of the exhaust pipe) to fit under the hood without hitting anything, welded plates top and bottom. I think there was only a half inch or so from the right side of the ex. pipe to the right side of the muffler, to allow it to clear the
curve in the hood. Give the bottom plate sufficient clearance above the spark plugs.
Used gas welding at the time - I expect mig would work nicely now.
And if it hits something after you get it cobbled up, a right angle grinder will slice off any offending portions, and a scrap plate welded on to patch!
Built a similar custom under-hood for my 1939 AC B (Dad's first tractor!) to replace the original stubby straight pipe, and a later upright above-the-hood one that always shook loose) and it's still muffling too.
Merry Christmas to you and yours, Glen!
Jack
Thanks Jack, good ideas.
Happy Holidays to you!
Isn't your manifold threaded for a piece of 1.5" pipe? If so, you can use a piece of pipe to get above the hood, then get a muffler that will fit snuggly over the pipe and clamp to it.