Why do exhaust pipes come out of the front of the engine?

[innominate]

Just been looking at a Moto Guzzi MSG-01.

The pipes come out of the front of the cyliders and then sweep back.



Surely it would make more sense to turn the cylinder around and have the pipes coming out of the back. So you have less pipe & hence less weight.



Or is there some obvious downside to this I am not thinking of...


https://www.onyerbike.net/2004/images/guzzi/mgs.jpg
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[Robby]

A few advantages of having it how it is.

Cooling. The fresh charge coming in cools the inlet sit of the cylinder, the exhaust heats the exhaust side, so its a good idea to have the hot side facing into the airflow.

Exhaust pipe length. The exhaust needs to be the right length to get the right amount of power at the right place in the rev range.

Also having the exhaust coming out the front means the carbs have a nice place to nestle out of the elements, directly next to a good space for the airbox, and directly under the lowest part of the fuel tank.

[Barry_M2]

TZR250 3MA (Reverse Cylinder) has the exhaust's exiting the 'wrong' side, with the carb's at the front of the bike.

https://i21.photobucket.com/albums/b272/parkerp/IMG_0597_sml.jpg

But, that way round you have no space for an airbox and you'll also get a very hot bum!

[Rookie]

Someone posted up pictures of a 'reverse engine' bike which I think was a 250 GP bike or something. I know virtually nothing about the mechanics of it, but apparently it makes it extrememly powerful and very unreliable and dangerous.

[Richy]

might be getting the wrong end of the stick here cos i dont know the bike but it looks like a v-twin mounted transversely, like a boxer engine, this would give much better cooling cos the engine is 'in the wind'

[owdamer]

VFR's have 2 pipes from the rear of the back cylinders, but then they head frontwards before doing a u turn and heading back.
Like robby says, exhaust pipes need to be a certain length. They dont just make em long to keep the fumes away from your face.

[cagiva gezzer]

Some more thoughs.

I'll post the cannondale piccy as i like the engine.

https://www.off-road.com/dirtbike/aug2001/cannondale2002/REVERSED%20CYLINDER%20HEAD.jpg
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