Shannon pipe question

robwijnstok · 15th May 2009, 19:01

Nosing around the forum I was triggered by the threat of T-Cut with is excellent how to replace you Shannon pipe.

How to of T-Cut is here http://www.the75andztclub.co.uk/foru...hlight=shannon

When I was in Germany a couple of weeks ago for the replacement of my cooling fan motor I saw that my Shannon pipe was starting to fall apart. The guy who was working on the 75 told me not to bother, there is only a danger while driving fast though deep water so don’t do that and you will have no problem. The engine can suck up water and can stall because of that as we all know.

Now triggered and reading lots of posts regarding the disintegrating Shannon pipes I was wondering does it affect your MPG positive or negative? Or is the engine influenced in an other way? My first theory is that with a disintegrating pipe the engine can suck in more air. My second theory is that the venturi on the beginning of the pipe must have a purpose, this intended effect must be lost when the pipe is not airtight anymore.

Puzzled again,

Rob.

Simon · 15th May 2009, 19:21

I believe the only real-world benefits of the Shannon tube are the increased protection against your engine sucking in water when going through deep puddles/fords etc.

I would be inclined to replace the tube if you drive in an area prone to flooding or if your car is a daily driver and you might encounter a situation which might pose itself.

Otherwise, you can leave the tube in its disintegrating form but you would just have to be wary of deep puddles and large amounts of road-spray.

I removed my tube a year or so back with no ill effects but then my car is fortunate enough not to be a daily driver.

T-Cut · 15th May 2009, 19:28

Thanks for reading it.

I don't think the plastic venturi piece has any significant effect on the air flow. It's a simple way to terminate the fabric pipe which is spiral wound and can't be finished off any other way.

The positioning of the open end is important to prevent water entering the air inlet system. If the Shannon tube becomes submerged when the engine's running, it won't just stall, it will suck up enough water to fill one combustion chamber and the engine will lock instantaneously. This can severely damage the internals, sometimes requiring a complete new engine.

The length of the Shannon Tube has no effect on performance or fuel consumption (not in these engines anyway).

TC

15th May 2009, 19:21	#2
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	I believe the only real-world benefits of the Shannon tube are the increased protection against your engine sucking in water when going through deep puddles/fords etc. I would be inclined to replace the tube if you drive in an area prone to flooding or if your car is a daily driver and you might encounter a situation which might pose itself. Otherwise, you can leave the tube in its disintegrating form but you would just have to be wary of deep puddles and large amounts of road-spray. I removed my tube a year or so back with no ill effects but then my car is fortunate enough not to be a daily driver.

15th May 2009, 19:28	#3
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,753 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Thanks for reading it. I don't think the plastic venturi piece has any significant effect on the air flow. It's a simple way to terminate the fabric pipe which is spiral wound and can't be finished off any other way. The positioning of the open end is important to prevent water entering the air inlet system. If the Shannon tube becomes submerged when the engine's running, it won't just stall, it will suck up enough water to fill one combustion chamber and the engine will lock instantaneously. This can severely damage the internals, sometimes requiring a complete new engine. The length of the Shannon Tube has no effect on performance or fuel consumption (not in these engines anyway). TC