bore size?

[mcgrath]

heh guys maybe someone can help me out. I seen a piston today and it was a .050 how many cc would this be?

[Snipe]

Im thinking .05 is minimal bore like a 406 or something. But I might be thinking backwords as im sick lol.

[mcgrath]

no I know .050 is 1.27mm just not sure what that would make the displacement.

[mcgrath]

409cc isnt that odd?

[killer400ex]

you also have to calculate in the size of the combustion chamber, my guess is that would make it a 416

[Snipe]

It is odd but most if not all big bore kits round the size up. I believe a 440 is actually like a 436 or something like that.

[TRXRacer1]

Originally posted by killer400ex
you also have to calculate in the size of the combustion chamber, my guess is that would make it a 416 No you don't. Chamber size has nothing to do with displacement. You only need that info when calculating compression.


Originally posted by mcgrath
409cc isnt that odd?
That's what I got too and I've never seen one that size yet.

[TRXRacer1]

Originally posted by Snipe
It is odd but most if not all big bore kits round the size up. I believe a 440 is actually like a 436 or something like that.

Standard Bore 397 85mm
407 86mm
416 87mm
426 88mm
431 88.5
435 89mm

[mcgrath]

Oh well I guess it doesnt matter, Its round and goes up and down. The reason I asked it cause thats what I put in my bike a couple of months ago but I thought it was a 416 until I got to thinking. I seen one the same and thought I should figure it out. Oh well works good. I dont have anything to compare it to for power because the bike was blown up when I got it. lots of meat left for the next meltdown I guess.

[TRXRacer1]

Do you mind me asking what brand of piston this is? Do you have a link?

[mcgrath]

Yeah it was a namura piston, but I went on their site and couldn't find a match. I seen one on ebay again but dont have a link, cant remember where exactly it was. But it was difinately a namura.