crank stuffer

[bigbellybob]

look at these crank stuffers
http://www.ozebook.com/compendium/t500_files/grant/imagepages/image34.htm

[stewart]

great pictures

[maddoggy]

stewart, sorry for the late reply. i did some looking at the crank stuffer idea i had and i decided that the idea i had will not work. however i was wondering if it would be possible to extend the tabs on the bottom of the cylinder slightly.  1/4" worth of extention would help in a similar way as BDI's latest intake mod. by the way, good thinking there Brian, do you plan to fill a little more?  MADDOGGY

[BDI]

Just to let you know the cylinder I'm welding on is junk I try out my ideas on it and there is no stress. I have a good grasp on two stroke design but applying my ideas can bee tricky so I do it to that cylinder for the practic of doing it. what I have done could easily bee done and probably done better with some sort of epoxy like JB Weld or my favorite marine tex. If you did this and you are using a V-force you will have to clearance for the petal screws but thats it. I don't think you can go wrong with this. You can over stuff a motor but you would have to work real hard to achieve it.

[kaw rider]

i have some ratio number for big single 2 smoke motor. do anybody have the ccr numbers.

[BDI]

i have some ratio number for big single 2 smoke motor. do anybody have the ccr numbers.

 
 

I think you are just going to have to cc the bottom end yourself. Do you really want to depend on what someone else says?.

[kaw rider]

i'm not to the stage of the dyno testing yet. working on different things now. but i will when i get there. i did find one error in cylinder. it short cycle the ports.

[BDI]

i'm not to the stage of the dyno testing yet. working on different things now. but i will when i get there. i did find one error in cylinder. it short cycle the ports.

 
   If your talking about the fact that the piston does not go down far enough to uncover the transfer ports Your right on the money. This is good for a few horse power when corrected and there is a couple of ways to do it and there is some numbers to correct it by but I'm not sure if I want to go blurting them out.

[kaw rider]

that's not the one that i found. what would happen if the piston shirt didn't cover the exhaust port at tdc.

[BDI]

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.   

[kaw rider]

bdi
the aux exhaust ports short cycle. but that wouldn't be a problem intill kips open up. look at the picture i posted with the kips drum. what looks different with it.

[BDI]

Well you successfuly got me confused. If your talking about the fact that the kips drums dont  uncover the secondary exhaust ports completely thats a easy fix just a little grinding fixes that. I dont get what you mean by short cycle.

[kaw rider]

can somebody post a picture of a oem cast piston.

[BDI]

I have ben in the shop playing with a piston and cylinder to try and figure out what you are talking about. If you are talking about the cut out on the side of the piston causing the secondary exhauste port and the forward transfer port to overlap I think that is one of those two stroke things that you can't do anything about.

[kaw rider]

yes you did find it. yes there is a fix. weld up both port around 1.5mm narrower. i do that done when have many other things welded on the cylinder at the same time.  i done it on my current cylinder.