Power valve bearings mods

[p51mustang]

Hi guys well my brain has ben at work . Subject power valves and bearings has any one tried ceramic bearings in place of the bushings . Just some thing to piss around with any one see any rite ups on this ??

Thanks Larry

[two-stroke-brit]

there was a thread some time ago about using needle roller brgs.
i thought ceramic were more for high speed applications rather than high temp.

[p51mustang]

ceramic can run under the heat i do no that

[p51mustang]

I thinking needle bearings wood plug up under oil and carbon

[(F5)]

My GasGas just uses normal bearings

[two-stroke-brit]

My GasGas just uses normal bearings

when you say "normal" brgs .
what do you mean, are they ball brg or a bush type .
thanks mark

[p51mustang]

I was all so thinking of getting them Hard anodized that will give you a no stick suffice last longer and take the heat better

[p51mustang]

I have a 2 set to pis around with here as far as using ceramic bearing 1 they can take the heat I have them in my 2010 dodge challenger rt wheel hubs at 180 mph they get hot [ Performance bearing] can make any size you can come with they are made in house

[(F5)]

Balls, inspector. (Sorry old telly add you've probably never seen)

http://www.ebay.com/itm/GAS-GAS-EC250-9 ... Sw6n5XvBEk

[Smoker]

Is there any performance gain or easier maintenance that would come with this mod?

It's not something that would be seen.

Not sure why this would be a good thing.

[Bare]

A few years back there was an Italian RZ nutter who Very skillfully fitted ball bearing races to his PV's.
Excellent craftsmanship. So it's clearly possible.
There was no evident follow up though .. as in: How did this improvement work survive carbonised goop /exhaust .
Not very well on a street use engine..I would guess.
PV's as designed by Yama are poorly thought out.
The ali shafts turning in their bushings get chewed up rather quickly. Doubly quickly when there is no maintenance .
IMO a permanent fix would be to fit steel sleeves to the PV bearing shaft bits then bore ream the Bushings to a decent fit.
Far cheaper than buying fresh Bushings which would still have a clapped out fit.
Likely a simple and durable "fix" for what Yama San bungled.

[RuZty]

...and drill a passage with a grease fitting at each bushing to allow occasional lubing without having to take the top end off.
Seals might need a rethink to not be pushed out by the grease.

[evan_calgary]

As an engineering challenge sounds like fun but the barrels wear out almost as fast as the PV surfaces. ie, 30-60k KM.

I have seen a lot of barrels and few (likely none) that the PV surfaces were the limiting factor. No performance gain other than potentially opening at a more accurate rate due to lack of drag from the motor. Possibly why Yamaha didn't bother with a more intricate solution?

Steel sleeves would have to be used to protect barrels surface otherwise you still end up with steel rotating on aluminum. Would the ball bearing against the aluminum barrel wear more slowly or faster? More force on a smaller surface area.

If you want a challenge, go at it but for me you are throwing money at a problem that doesn't really exist.

[p51mustang]

Thanks Even just pissing around here not spending money on this i have all the parts to do this who no;s it mite just work and all i am doing is pissing around with some parts

[p51mustang]

As an engineering challenge sounds like fun but the barrels wear out almost as fast as the PV surfaces. ie, 30-60k KM.

I have seen a lot of barrels and few (likely none) that the PV surfaces were the limiting factor. No performance gain other than potentially opening at a more accurate rate due to lack of drag from the motor. Possibly why Yamaha didn't bother with a more intricate solution?

Steel sleeves would have to be used to protect barrels surface otherwise you still end up with steel rotating on aluminum. Would the ball bearing against the aluminum barrel wear more slowly or faster? More force on a smaller surface area.

If you want a challenge, go at it but for me you are throwing money at a problem that doesn't really exist.

That is some what close to what i am trying to do