Best for newb to use
and opinions
is namura good?
AND HOW MUCH PISTON TO WALL CLEARANCE FOR RIDING MODERATELY HARD?
and opinions
is namura good?
AND HOW MUCH PISTON TO WALL CLEARANCE FOR RIDING MODERATELY HARD?
Piston choice opinion
- Thread starter shiftngeer
- Start date
Wiseco, Wiseco, Wiseco, Wiseco!! Don't cheap out on a piston, gaskets, or seals for your engine. Use OEM gaskets and seals and run a Wiseco piston. Trust me, they hold up well and are worth the couple extra $ over a Namura. I ran the Hell outta my Wiseco piston-equipped Blaster this weekend at Busco.
I'm talking aggressive trail riding and 5-6 passes on the drag strip at WOT, one right after the other, running 50:1 pre-mix. I only run my Blasty that hard if I know the engine's gonna hold up. A cast piston can shatter at the skirt and the little pieces often screw up the whole bottom end in the process. Go Wiseco.
I'm talking aggressive trail riding and 5-6 passes on the drag strip at WOT, one right after the other, running 50:1 pre-mix. I only run my Blasty that hard if I know the engine's gonna hold up. A cast piston can shatter at the skirt and the little pieces often screw up the whole bottom end in the process. Go Wiseco.
Blaner
Your Friendly South African Ambassador
nothing is wrong with Namura, Vertex or ProX Pistons! they are CAST and not FORGED, meaning they are more brittle and do not stand up to loose bore and piston slap.
Namura and Vertex make use of a molydenum skirt coating to aid breaking in and reduces wear.
ProX are the OEM suppliers to Yamaha for blasters and Vertex are the OEM suppliers for KTM.
Cast pistons require a tighter clearance around 0.04mm - 0.05mm NO BIGGER! any bigger ans the skirt WILL shatter.
Forged pistons need a looser bore, 0.05mm - 0.07mm. If the bore is too tight for forged pistons, it will sieze as they expand in a non-uniform manner and often results in the piston being a out of round shape while expanding, remember the exhaust side expands more and faster than the intake. This is the only real advantage of cast pistons over forged - cast expand uniformly and thus can be run tighter.
Cast are cheaper, and if fitted and jetted correctly can perform just as well as a forged. But IMO, i will always run forged.
Namura and Vertex make use of a molydenum skirt coating to aid breaking in and reduces wear.
ProX are the OEM suppliers to Yamaha for blasters and Vertex are the OEM suppliers for KTM.
Cast pistons require a tighter clearance around 0.04mm - 0.05mm NO BIGGER! any bigger ans the skirt WILL shatter.
Forged pistons need a looser bore, 0.05mm - 0.07mm. If the bore is too tight for forged pistons, it will sieze as they expand in a non-uniform manner and often results in the piston being a out of round shape while expanding, remember the exhaust side expands more and faster than the intake. This is the only real advantage of cast pistons over forged - cast expand uniformly and thus can be run tighter.
Cast are cheaper, and if fitted and jetted correctly can perform just as well as a forged. But IMO, i will always run forged.
i was reading this thread and i just had a question about the piston in my blasty. i have a namura piston in mine and it has stamped on the piston 67.42 for the piston size so i beleive that would give me a 67.50 bore size witch is .60 over right? that would leave .08mm clearance for the rings right? it says i should have .04mm to .05mm clearance for the rings and 67.50-67.42=.08mm thats more than .05mm is that bad or im just doing the math wrong?
I bought a numara piston for my 300ex and had to cut and set ring gap on rings. However with every wiseco piston ive ever bought the rings have come cut and gapped correctly for instant install.I never ran a vitos but i will always run a wiseco on about everything i own.
oh. idk if the rings for the namura were cut or not when i got it bored over thats the piston that they sold me to go with it. so if i wanted to go to put a wiseco piston in it could i just buy a .60 over wiseco piston and it work fine? no setting the ring gap or nothing?
Blaner
Your Friendly South African Ambassador
ring gap has nothing to do with the rings themselves but rather with the bore size! although, if your bore is within spec (0.04-0.05mm) then the ring end gap should almost be right, but you should always check and adjust if necessary, there is no shame on the manufacturer for them being out of spec, thats up to the mechy who installs to check
Are you sure that says 67.42 and not 67.45? it should say the latter..double check that with a magnifying glass if you not sure.
I'd go with a wiseco. And if your motor is stock, go with the recommended clearance of .002" and if your motor is moderately-heavily modded, go with around .003" clearance.
If something bad goes wrong you risk breaking the skirt off on a cast piston. Usually a forged piston will just seize in the bore. A lot cheaper if it does go wrong. Trust me, I know lol
Vito's forged super stock, all of the great benefits of a Weisco piston (b/c Weisco makes it) + a trick lil design to add clearancing on the exhaust side.
