Rain Cap

And your also right on rain caps, over the years I've seen tractors with rain caps blow just as much black wet soot as the tractor not even covered in an overnight situation. Long term would be a different story.

If one measures the size of a stack, times the inches of rain fall, the volume of water over night will be quite small as long as water hasn't been deflected artificially. Tractors out in the open as long as the exhaust is tight will never get enough water to hurt anything even with stack uncovered over night.

I remember once my Farmall 300 and 560 sat for two days in an open field, in a 9" rainfall. 560 had a rain cap, 300 stack was not covered at all. They both fired right up, and both blew about the same amount of black wet soot.

I don't know what some folks use when they talk about heavy rain caps. I remember an old guy with a D7, used to do custom bulldozing in our area. He used to put a brick on top of the rain cap. He had more dings on the hood of that old D7 from the brick falling off. I never could figure why he didn't just throw the rain cap away and carry a can that fit snugly over the stack. I guess the brick stayed on the operators platform, better than the can during the bulldozing hours.

I guess most folks that like rain caps like the rattle at idle speed. At least I've seen guys adjusting their throttle to get the rattle just right before dismounting from the tractor.

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Anyone that ever got enough water over night to in any way adversely affect the engine, either had it sitting under a tree, in the down draft of a building or other object or the exhaust had leaks below the hood likely at the manifold. Maybe the cap was up in the wind, just a catching water.

If you put a rain cap on most gassers heavy enough to stay closed it creates too much back presure on the engine. Those little engines don't blow the volume of air diesels do. The gas engines also burn the edges on rain caps very quickly. I happen to know Mitch, and his tractor is a little offset Farmall, take note of the small pipe. If you leave those pre 1962 Farmalls plus the 140 and Cub out in the rain often, because of the design, they will have more water in the transmission than the engine even if the stack is left uncovered. Most makes of older tractors, prior to the early 60s were not very weather proof.

I farmed for many years, bought a lot of new tractors. In my lifetime I've owned 16 Farmalls, 1 Cockshutt, 1 Deere, 2 Case and 1 MF, most of those bought new or very close to new. Amoung them, 5 - 6 cylinder diesels, 2 of those equiped with turbos. I have never rebuilt a diesel under 10,000 hours, and those 5 diesels probably logged about 75,000 hours on my farm. Those diesels all came new with rain caps, and yes many times I've seen those caps wide open in the rain and wind. I can tell you that if those diesels were not being used for a week or more, a bucket with a wire bail was placed over the stack and rain cap as insurance, and tied in place. I might add, I've seen those diesels, with good rain caps, blow just as much black wet crap after a rain as my old Farmall 300 with nothing over the stack.

Now, I want you to tell me why those other 16 gas tractors I bought in my lifetime, did not come equiped with rain caps. Did you ever think, maybe the manufacturers knew rain caps wouldn't work on gassers?

If rain caps were so damn great why have most new tractors and construction equipment gone to exhaust systems that don't go directly down to a manifold or turbo. Those new exhaust systems all have a low point with a drain, before water can get to a manifold or turbo. Most of them don't even use rain caps anymore.

If your exhaust is tight and tractor is out in the open, even in a 2" rain fall over night you will get very little water down the stack. The important part is that it is started the next morning. The only time I ever cover tractor exhausts is if the tractor is going to be parked for more than a day. The old soup can is still the best insurance against water down the stack. Keep the can very little larger than the stack so wind wont blow it off. I keep a sized soup can in every tractor tool box. In fact I had the same soup can in my 130 for about 10 years now. Had to replace it last week as it had a hole rusted in it.

The other matter I found over the years is rain caps don't last very well on gas engines. I had them on big diesels and they lasted 5 to 10 years. I once put one on my SA and it burned the outer edge of cap off within the first year.

Remember if the soup can is sized, it is virtually water proof. In fact the only time I ever had problems with water getting in the tractor exhaust was a loose pipe where it entered manifold on my Farmall 300. That was clearly water running along the hood and following the pipe. The exhaust actually had a soup can over it.

Soundguy