Author Topic: strange mx100 piston  (Read 2878 times)

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Offline mx250

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Re: strange mx100 piston
« Reply #10 on: July 14, 2011, 06:12:50 PM »
Actually Dykes Rings have a lot of advantages and few disadvantages in the right application.  The Karts are single gear so raising the Ex port isn't a good idea since low-mid range will be lost.  So, the exhaust port wants to be as wide as possible to attain enough port time / area.    Dykes rings make this possible because they need very little outward spring force.  since they use compression to force them out against the cylinder wall.  So the rings have less tendency to "pop" out into a very large port.

The advantage is: The exhaust port can be run as wide as 80+% of bore without snagging a ring.  And the ring isn't dragging against the cylinder wall with a lot of force unless it's under compression.  By comparison a standard ring may be able to survive an exhaust port that is 72% of bore but that's pushing it...

They also provide much more precise port timing since the edge is so sharp, unlike the edge of the piston which has a small radius and doesn't touch the cylinder wall.

The disadvantage is that it's heavier and will flutter sooner than a conventional ring at high RPM, like above 10,000.

Very informative 8). But I still defy you to pick the difference on a 250 MX'er ;). Go Kart yes, 125 MXer maybe.

Offline Todd W.

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Re: strange mx100 piston
« Reply #11 on: July 15, 2011, 02:55:21 AM »
On a stock motor, you're absolutely right.  No noticeable difference whatsoever.  But I do like these style rings especially for building a torquey mid-range motor that will last.   ;)  They give the builder the advantage of more aggressive porting without the consequences of higher maintenance.