What's the lip inside the intake for? (GS450)

[Guest]

While pulling the carbs off for a much needed cleaning, I couldn't help but notice a lip cast into the mouth of the intake. For some odd reason I can't access my Photobucket account, but this seller on eBay took a picture of it as well:

http://www.ebay.com/itm/CYLINDER-HEAD-1980-80-SUZUKI-GS450-GS-450-/160593859595?pt=Motorcycles_Parts_Accessories&hash=item256423d40b&vxp=mtr

Anybody know why it's there and more importantly, would the engine breathe better without it? I don't recall seeing this grooved lip on a GS500 port.........

[7981GS]

Interesting...



Perhaps to intentionally disturb the air flow to promote better combustion?

Eric

[Big Rich]

Thanks for posting that picture Eric.

But that's what I thought too - it was to help atomize the mixture, or to direct the mix upwards and get it sucked into the valve opening. On the other hand, I know for a fact the GR650 head isn't designed that way. While I haven't actually worked on a GS500 head, I haven't seen that lip on one either........

[gearhead13]

Fuel usually puddles on the bottom of the port and that would help remix the fuel and air and promote more complete burn. Dont know why they didnt just make it a D shaped port or make it smaller. Engine builders sometimes fill in the bottom of the port with epoxy/JB weld to improve velocity.