Project "I needed to clean the air filter so I blew the motor"

[SHLEPY]

This makes a lot of sense if the jug has the ports why not the piston...Looks good Mr M!!!

[cbrfrenzie]

once again. this is all just REALLY REALLY ROUGHed out stuff.   dont judge radius's, exact shape, size etc    etc etc..

here is what I was thinking from the yz250 pistons.

this bottom cut CLOSES just as the transfers open......  which should keep it from starving the lower floor port and the boosters...


(last 2 pictures taken right as transfers open)

Interesting idea there with the lower piston skirt shaping there in the last 2 pictures.  I think we want to be careful with that area, as to not decrease the pumping effect of the piston moving down.  If there is an opening there when the pressure under the piston is greater than the intake, air will flow in reverse into the reed chamber.  Your pictures are very informative, I like how the angle you cut into the piston is different than than the angle of the boost port.  This gives a nice transition into the piston boost port, which will reduce negative turbulence as the piston moves upward sucking air into the case.  That angle and depth may be good parameters to experiment with.  Keep it up, I'm liking your ideas!

[Motorrad]

I 100% agree we need to be carefull in that area...    I think as long as it closes the bottom before the transfers open up... we should be fine...      

heck.. would be better than that low window in the "S" pistons.     that would be a problem just as you described.

[sandblaster]

How much closing is enough 

[Motorrad]

once again. this is all just REALLY REALLY ROUGHed out stuff.   dont judge radius's, exact shape, size etc    etc etc..

here is what I was thinking from the yz250 pistons.

this bottom cut CLOSES just as the transfers open......  which should keep it from starving the lower floor port and the boosters...


(last 2 pictures taken right as transfers open)

for refferance....  here is a "S" piston   in exactly the same location as the last to pictures above.     (exactly when the transfers open)          you can imagine how that would starve the rear boost port.......     and as far as lower skirt cutting.. the one I showed cut, that closes as the transfers open.. has to have better pumping action than the "S" piston, that is WIDE OPEN   ....    YES NO?  Im just going off my thoughts here...    What ya think CB?

[USMC 500]

What great ideas!!.......All this brain storming has really made me thirsty!!  Anybody want some?

[cbrfrenzie]

Just for clarification, are you we talking on the down stroke or up stroke?

I like the split boost design better than the large central boost port in the piston.  this will help split the air up and direct it towards the boost  ports, with minimal short circuiting.   How cool would it be to add extra oil holes on the piston wrist pin boss directly behind these new ports haha.

[sandblaster]

   How cool would it be to add extra oil holes on the piston wrist pin boss directly behind these new ports haha.

Dude!
I was thinking the same thing 

[cbrfrenzie]

   How cool would it be to add extra oil holes on the piston wrist pin boss directly behind these new ports haha.

Dude!
I was thinking the same thing 

hahaha that is too funny great minds think alike a... 

[Motorrad]

I can tell you from now on I'll be adding oil holes to the exh bridges

[Motorrad]

cross your fingers. just applyed food coloring to the exh bridges.

[USMC 500]

[Motorrad]

LOOK SHARP....    here comes the supervisor.

[Motorrad]

center divider   100% fail the food coloring test.   (PS..   red works better, shows up better,   but im out of red)


main divider.  pass.        but I still dont trust it.      

[Motorrad]

I will say... PROPS to millenium.     this plating is fine.   if it wasnt for the cracks... id run it..