# Rookie Question: Tractor Exhausts



## Diwali (Dec 26, 2015)

I started driving tractors in the UK 60 years ago and I have never seen here a tractor exhaust with a flap on the top but in the US they're quite common, especially on older tractors. This is probably a rookie question but what is the purpose of the flap? 
Please be kind with your answers!


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## marc_hanna (Apr 10, 2017)

To keep water out.


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## Diwali (Dec 26, 2015)

marc_hanna said:


> To keep water out.


Thanks. It's a logical answer but how would you explain why tractors in the UK (a wet climate!) don't have them, and never have to my knowledge? I'm still confused!!


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## jhngardner367 (Apr 5, 2011)

Most use cups,or tin cans ,to cover them,rather than a flapper valve,from what I've been told.
Americans just like watching it flap !


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## pogobill (Jan 31, 2012)

I get mesmerized by the flapping myself, John!


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## marc_hanna (Apr 10, 2017)

My brother-in-law forgot to put his can on one year and the engine got filled with water. The engine was ruined.


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## Hoodoo Valley (Nov 14, 2006)

Sometimes the exhaust hole is turned slightly to direct the exhaust and prevent rain from going straight down.


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## sixbales (May 18, 2011)

Howdy Diwali,

You do not need a flapper if you put your tractor undercover, so rainwater doesn't get in the engine. Like others have stated, you can put a can over the exhaust to prevent rainwater entry. The advantage of a flapper is that it doesn't forget to cover the exhaust !


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## Diwali (Dec 26, 2015)

marc_hanna said:


> To keep water out.


Thanks. It's a logical answer but how would you explain why tractors in the UK (a wet climate!) don't have them, and never have to my knowledge? 


jhngardner367 said:


> Most use cups,or tin cans ,to cover them,rather than a flapper valve,from what I've been told.
> Americans just like watching it flap !


 Ha ha! That brought a smile on a wet day! 
I delved further into the flapper conundrum: 
In William and Mary Morris' _Dictionary of Word and Phrase Origins_, they state, "In America, a _flapper_ has always been a giddy, attractive and slightly unconventional young thing. 
Okay.... I believe that type of flapper was popular on both sides of the Atlantic!!


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## Diwali (Dec 26, 2015)

[QUOTE
I get mesmerized by the flapping myself, John![/QUOTE]

That's a nice pair of flappers you got there Pogobill.


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## Diwali (Dec 26, 2015)

marc_hanna said:


> My brother-in-law forgot to put his can on one year and the engine got filled with water. The engine was ruined.


Yikes! Maybe I need to invest in a tin can! My Case has been outside for 2 years!


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## Diwali (Dec 26, 2015)

tractor beam said:


> Sometimes the exhaust hole is turned slightly to direct the exhaust and prevent rain from going straight down.


Yes. You're right. The vast majority of modern tractors both sides of the Atlantic have a curve/bend at the top which would presumably reduce water ingress.


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## Diwali (Dec 26, 2015)

sixbales said:


> Howdy Diwali,
> 
> You do not need a flapper if you put your tractor undercover, so rainwater doesn't get in the engine. Like others have stated, you can put a can over the exhaust to prevent rainwater entry. The advantage of a flapper is that it doesn't forget to cover the exhaust !


Good point about forgetting to cover the exhaust Six Bales. Judging by the comments on here and that my tractor is stored outside, I thought it wise to consider some rain protection. A search on the Internet enlightened me enormously:
1. A flapper is termed a 'rain cap' by suppliers
2. Lo and behold rain caps are manufactured and supplied in the UK! One supplier stated 'In a country where it rains this much it's important to keep rain water out of your tractor's exhaust system.' 
3. Rain caps are relatively inexpensive and readily available in all sizes in the UK (I suppose most farmers here have tractor sheds that's why they don't fit them??).


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## sixbales (May 18, 2011)

I rarely leave my tractor outside overnight. Never if there's rain in the forecast. Here's an extreme example.....Hurricane Harvey dumped 30 inches of rain on my place over a period of 3 days. That's a lot of water for an engine to ingest. Might not crank, or it might bend a rod?


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## Diwali (Dec 26, 2015)

Thanks for all the comments on exhaust flappers/rain caps. I now realise that a rain cap ($10) or a tin can (free) will, potentially, save me the cost of a new engine! It may have been a 'rookie' question to begin with but, thanks to this site, I'm moving up the learning curve! 
Cheers guys!


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## willys55 (Oct 13, 2016)

jhngardner367 said:


> Most use cups,or tin cans ,to cover them,rather than a flapper valve,from what I've been told.
> Americans just like watching it flap !


and go ting ting ting when at idle


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## Diwali (Dec 26, 2015)

sixbales said:


> I rarely leave my tractor outside overnight. Never if there's rain in the forecast. Here's an extreme example.....Hurricane Harvey dumped 30 inches of rain on my place over a period of 3 days. That's a lot of water for an engine to ingest. Might not crank, or it might bend a rod?


Woah! 30 inches!! That IS a lot of water. 
Sadly, my tractor shed project has been delayed and delayed (sometimes due to the weather, LOL!) so my poor tractor sits outside all year round. Maybe next year it will have a cosy home??


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## Diwali (Dec 26, 2015)

willys55 said:


> and go ting ting ting when at idle


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## FredM (Nov 18, 2015)

We used jam tins here in Nth. Queensland, Oz. until the flapper became available, the jam tin though was usually blown off the exhaust, because these were usually forgotten about when the tractor was started, and if you were lucky, the tin would land on the ground and not the bonnet of the tractor.


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## Diwali (Dec 26, 2015)

LOL! I’ve often seen beer cans in the Aussie countryside but if I see jam tins I’ll know where they came from!


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## geoff l (Oct 10, 2017)

A lot of manifolds had a deep hole in the lowest portion of the castings, these soon blocked through rusting, you gotta have a flapper if you want your tractor dapper!


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## MHarryE (Oct 28, 2011)

The flappers are notoriously unreliable. The exhaust actually pulses with each exhaust stroke and the pins wear off, the flap falls off resulting in water in the engine. Solution is curved pipe. Smaller tractors have horizontal low exhausts also eliminating the need.


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## LouNY (Dec 15, 2016)

But it's so much fun watching the can go flying in the air, till I have to drag my butt out of the seat and go pick it up to have when I shut her down I do like a good rain cap better.


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## ben2go (May 28, 2008)

Most exhaust have a weep hole in the lower, or lowest, point in the exhaust system to allow water to drain out. Some older tractors in the US didn't have this and instead came with a flapper. Some exhaust on tractors went directly into the top of the exhaust manifold and a weep hole would not help there. Water would still enter the engine. The flapper, can also be used to help redirect exhaust by facing the flap away from the cab. We have a lot of open cabs in the US. I see a lot of closed cabs in the UK and EU from pics and vids. I can't comment specifically on why UK don't use flappers. Maybe something I mentioned here can help explain why or why not the tractors over there don't use them.


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## willys55 (Oct 13, 2016)

even in cars today they have weep holes in the mufflers, dont help much, that seems to be the hole that gets bigger first...LOL


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## pYLON1357 (Dec 2, 2016)

I put a rain cap on my exhaust this summer. I used to use a tin can to keep the rain out, but being dumber than a bag of hammers, I used to forget to remove it all the time. Not a problem, throttle up and off the can comes. It always seems to land right under the bloody wheel. 

My rain cap doesn't do the flappy flap flap thing. It just opens and stays that way until I shut down.


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## Diwali (Dec 26, 2015)

ben2go said:


> Most exhaust have a weep hole in the lower, or lowest, point in the exhaust system to allow water to drain out. Some older tractors in the US didn't have this and instead came with a flapper. Some exhaust on tractors went directly into the top of the exhaust manifold and a weep hole would not help there. Water would still enter the engine. The flapper, can also be used to help redirect exhaust by facing the flap away from the cab. We have a lot of open cabs in the US. I see a lot of closed cabs in the UK and EU from pics and vids. I can't comment specifically on why UK don't use flappers. Maybe something I mentioned here can help explain why or why not the tractors over there don't use them.


Thanks for an exhaustive explanation (excuse the pun). You may have answered the question as to why in th UK rain caps are not common.


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## Diwali (Dec 26, 2015)

Rookie rain cap Mark 1. (Patent to be applied for)


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## geoff l (Oct 10, 2017)

Looks great!, But I would have the label off, spray it yellow, and you will find it easier to retrieve when you fire the tractor up and it goes into orbit....


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## crawdaddy (Dec 7, 2011)

I have no need for cans or flappers..my exhaust goes down under and out the rear end...I never get a whiff of exhaust in the face.......


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