exhaust port (for specialists)

[Ketje]

Anybody an idea what this exhaustport-shape is good for? Pro's and con's??? Or is this just to get the same effect as an exhaustport with two auxiliairy ports without the risk of breaking the bridges from the auxiliary ports?

[OAP]

The bottom shape of the exhaust port is because of the width of the exhaust skirt of the piston at T.D.C, the rest is obvious.

[Ketje]

Yes OAP, but will this work better then normal exhaustport with 2 auxiliary's?

Mike.

[Muppet]

gives y a wider leading edge; an itll ave more leading edge than std port; similar has been dun in the std class; not identical; with some of todays race scooters; but sum woodnt say so if y asked em; ifin y look in y 2T toonin books itll tell y it give ya greater mean port/time area cus more of y port area is biased to leadin edge of port; y standard port would ave a lower mean port time/area cus the widest span in the port is biased lower down the pot; givin y two port types with same area different power cus of were port is biased; lower edge Ron said
muppet

[Darrell Taylor]

POLINI W PORT

italkit used gilardoni cylinders which were cast offs from polini that gilardoni got away with using as they made subtle changes to the basic design
the original polini w port design and italkit uses the 3 overlapping fingers to carry the ring at all times allowing a wide port to be produced but no wider than can be done with a common triple port design which has the added benefit of an independant closed off port floor to the aux ex port which reduces short circuiting

dont think polini ever used it in there high end race kits although a very good performer they just used it on the fast road kits where its fancy name and novel design did some good sales

[Ketje]

Thanks guys,
Mike.