Mf65 Exhaust Discharge options

I'm working my way through various issues having to do with the MF65 tractor I just bought.

The otherwise good muffler stack was broken off 4 1/2" below the bottom edge of the hood while the previous owner was mowing under overhanging branches. I expect to encounter similar situations frequently when mowing and thought I might buy an orchard (underslung) pipe to avoid the problem. I was warned this would increase fire risk, due to the pipe's proximity to the ground. I considered adding a spark arrestor to the system to counter the risk, but I know nothing about them. I'm aware there are other issues concerning the effect of tractor exhaust discharge from various locations. However, an important one to me is limitations imposed on a tractor's movement by a stack pipe.

I believe I recall seeing a couple of tractors with the exhaust pipe turned forward and discharging toward the front. The discharge was higher than an orchard pipe's.
If I was to do this on my MF65, I'd have the exhaust shop cut the exhaust pipe low on the offset and have them fab a fairly tight bend from there toward the front. The muffler would attach at the end of this bend's discharge. The bottom of the muffler would be about 38" above the ground, next to the steering link) the tailpiece would end at this height near the grill and axle. The discharge would point a few feet to the left and front of the tractor. Maybe some kind of spark arrestor could be located there too, if I decide they are effective.
Dale

The standard Under exhaust would lead down from the engine and run back under and with the muffler located under the operators step with the discharge pointed down toward the ground behind the rear axle. I
don't know where you are but here in tenneessee ground fire ignition would be extremely, extremely rare. We did not riding the tobacco setter with a rear discharge tractor!

I have a 50 and my son has a 65, both with the down and out back exhaust. I would not mow tall very dry grass/weeds but have not had a problem mowing green and greenish grass and weeds. Sunflowers and Johnson
Grass taller than my head standing up running the tractor.

I think the under axle discharge would have a low fire risk. Cut a bit off the end so it exhausts straight back.

I have a MF 20C diesel with the turn down out back exhaust. I had the same concern about starting a fire. However I have measured the muffler and exhaust temperature with an IR thermometer on numerous occasions and the highest measured was 135 degrees. I wouldn't set and idle in tall dry grass but, I've never had any issues.

Not so much the exhaust blowing down on dry grass. If it were stationary, running under load it might be a concern.

But the problem is more grass packing in between the running board and the pipe, or anywhere it can pack in and remain in contact with the exhaust.

Even then it would need to be under heavy load to get hot enough. And you would likely smell and see it.

On the farm where I grew up, we had an 8N for 29 years and a Massey Ferguson 65 High Arch gas for 24 years with the original style horizontal exhaust pipes and mufflers. We never started any fires. The fumes from a forward facing exhaust would likely come back in your face.

someone is handing you a line of BS i'am 68 and have had horizontal ex.on a ton of tractors and not one fire and i cut a lot of marsh grass

The muffler sits up along side of the exhaust manifold and only the exhaust pipe would be down below.

Steven

A buddy owns 30+ Farmall H/M/300/400 etc. tractors set up for city sidewalk snowplowing. He modifies them with horizontal mufflers laid atop the hood with the outlet elbow facing 45 deg down (photo).

I've plowed many miles of sidewalks with the outfits - the muffler setup works great!

If the fire hazard for underslung exhaust was that great, the N series Fords would never have caught on. It's not impossible, just improbable that you
would have an issue with fire.

Mike

(quoted from post at 19:49:32 09/17/20)
"I've plowed many miles of sidewalks with the outfits - the muffler setup works great!"

Click to expand...

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My proposed discharge location will be similar to the photo except about 6" lower and just above the front axle on the left side. I might experiment with a coupling and clamps before having something properly made.

Could you compare the operator fume exposure from this to a stack exhaust?
And thanks everyone. This helps.
Dale

Just get a muffler for a combine. Our old Gleaner had a muffler that blew out to the side that kept from going higher than the rest of the machine. Another local guy had something similar only it blew up at the end of the muffler about enough to get a rain cap on that was it. I hate all the maintenance required to get under slung exhaust on and keep it up over the years.

I thought he had a diesel.