Maintenance & Technical > KX500 Original
crank stuffer
BDI:
--- Quote from: doordie on December 29, 2007, 11:27:38 PM ---
--- Quote from: BDI on December 29, 2007, 04:45:26 PM ---If your piston skirt does not cover the exhaust port at tdc then someone has lowered the floor of your exhaust port to meet the top of the piston at bdc. This would normally be a performance mod on a two stroke motor. On the KX500 the piston skirt is not long enough to cover the port at tdc. This is bad. It's going to allow the return wave from the pipe to shove exhaust underneath the piston and foul the intake charge with exhaust gasses. I have thought about contacting Wiseco about having pistons made with a longer skirt but it would be more work than it would be worth unless I was going to have a bunch of pistons made.
--- End quote ---
IF you raise barell and shave of top of barell,you have a win/win situation.
No more uncovered exhaust at TDC and raised portduration for more power/RPM at the same time..... :wink:
(You can also deepgrove cylinderhead and not shave barell at top)
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I think a good number to raise the cylinder by is .040 you could accomplish the same thing by stroking the crank to 88mm that way the piston goes down 1mm further. I'm alll about stroking it :-D
maddoggy:
stewart, have you dyno'd an engine with a reed spacer installed? i'm just wondering if the spacer does indeed lower your horsepower a little just opposite of the crank stuffer. i would think it would but just looking for your dyno say so. MADDOGGY
maddoggy:
i was thinking about your reed area mod bdi. you could place some soft (modeling)oil clay in the side area and then push in a v-force, take it back out and shave for clearence. VOILA, maximum intake crank stuffage. take measurements and install marine epoxy to same measurments. what do you think? MADDOGGY
oh by the way, that is one sweet picture!
stewart:
i do not think kawisaki missed this fact that the last exh booster port to open,, the two outside ones had the highest duration for top end and it bieng directly above the intake transfer port with some short circuting happing at high rpm my help draw the charge in to cylinder case......ps reed spacers make less power but that can make the bike hook up better and thus seem faster or more ridable so theres a place for every mod..
BDI:
--- Quote from: maddoggy on December 30, 2007, 03:51:19 PM ---i was thinking about your reed area mod bdi. you could place some soft (modeling)oil clay in the side area and then push in a v-force, take it back out and shave for clearence. VOILA, maximum intake crank stuffage. take measurements and install marine epoxy to same measurments. what do you think? MADDOGGY
oh by the way, that is one sweet picture!
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I have thought of doing something very similar. I was thinking of making a mold and casting some stuffers out of liquid rubber. I think it would work good because the reed would hold them in place and you could take it out if you didnt like what it did. It would be the antispacer. :evil:
Thanks on the picture that is a actual picture taken on my work bench holding a torch in one hand and the digital in the other. That skull and cross bones Is a BDI original I got the copy right from the us copy right office not to long ago. I have stickers cut out of vinyl allready and I plan to have some beanies made up among other things.
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