polanda?

[woodsracer144]

ok, so i have a polaris big boss 400 and it useing the 400L cylinder, i have 2 or 3 of these now with crack from lobs for the base stufs but i'm getting them repaired and i would like to build a polanda, what crank shaft do i have to run. i've heard somethinkg about a KTM rod... i plan to run youkon gears... or else go though and harden mine... (im at collage in the welding lab and we have all kinds of sweet chit there)

I have an extra set of cases, and a bunch of parts so i might as well use them, i also have a BB pipe, so some one help me please. thanks

[morse250r]

my buddy has a pilot top end on a 250r based lower, there is a ton of work getting them set up right, rod angles piston combos ect. he has a 7mm rod with a puma piston in there now 449cc as far as rods kx500 yz 490 ktm there are tons of combos. there is alot of work to do to the cases ( if you wanna do it right)
as far as gears hardend wasnt nessasary an extreame build of a motor like this on average your looking at 70-80 hp on gas mid 80's on alky

[woodsracer144]

you dont need youkon's? 330's shatter them allthe time...

[Honda 250r 001]

Originally posted by woodsracer144
you dont need youkon's? 330's shatter them allthe time...

Im thinking it depends on where you ride. a tacky mx track will rip gears apart faster than the dunes!

[woodsracer144]

building it for a open tt, its a oval but it will be ran in all kinds of stuff...

[morse250r]

i was speaking of a sand dune drag race style

[woodsracer144]

i would think the dunes would be hard on it... huh? thats weird... theres a few really sandy spots around here and it just robs power like a MFer... its a pain to get through...

so this is was thinking...

running a sort or spacer plate you could say but it would be welded to the cyl... and run a longer rod so i wouldnt have to worry about the piston hittin the crank shaft...

did they use the whole KTM crank ***. and mod it or just ues the rod? i would like more information if possable... thanks

[woodsracer144]

so i grabbed my extra set of cases and my cyl and brought them inside to take a look at them...

i found that the holes dont line up one bit!

good deal! reasons for me to run the mill! hahaha!

the one thing that im not sure about is if i was to have the cylinder towards to rear of the cases or towards the front.
I was thinking of taking the front ones and egging them out a little you could say...

i think the easiest way for me to get this done would to take a base plate as a "jig" you could say and then fill in the wholes and reinforce them as well and then re drill them out.
this would go for both front and rear holes... but im not a 100%
where the cylinder should sit..

would the OEM rod hold it?

i have a 86 crank that is OEM but needs a rebuild and i also have a OEM crank with a hotrods connecting rod...
i have the hot rods in another bottom end waiting on a cylinder and a clutch and that will be ready to go...

if some one has one of these cylinders and has it off if they could give me some numbers on where theres is sitting that would be great!

thanks

TT her we come!