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Things that make me go "Hmmmmm" Part Tre....

Posted: February 2nd, 2009, 4:23 pm
by Skidmark
Why do ALL inline (not "V" or square or "flat" shaped) motors that I can think of (off the top of my puny, slightly pointed head) have the intake behind the engine subjected to a lot of heat and the exhaust system in the front and having to make a innefficient "U-turn" to get to the back of the bike to be expelled??

Wouldn't you think it should be the other way around??

I remember seeing something on this in an old magazine...but it didn't jive.

Let's hear your theories Hoons.

"Skiddy"

Posted: February 2nd, 2009, 4:56 pm
by MICK
Well any inline engine I can think of (Sport Bikes) do take the incoming air from the front. Right through the cowl. Seems pretty efficient to me, a little ram air like actually. And the header on my V-Twin Super Bike does lead out the front of the cylinder and make a U turn back to the rear. An issue I think with having the headers come off the rear of the cylinders is there isn't any air (or damn little) helping heat trapped between the spars escape. Introduce headers into that space and you'll melt your balls onto the gas tank.

Snowmobiles were like that for years and years. And have only recently started swapping the exhaust and intake to sides they perform best at.