Valve clearances

[yorkie_chris]

Originally Posted by rictus01

thermal dynamic wear pattern

F#king hell

Thats a big term

[rictus01]

Originally Posted by yorkie_chris

F#king hell

Thats a big term

true, but once again, not wrong.

Cheers Mark.

[yorkie_chris]

Indeed, and it appears to have shut blue up...

Originally Posted by yorkie_chris

Indeed, and it appears to have shut blue up...

What’s wrong with you people?!?!?

Anyway, having logged back on and seeing we have got no further, just done some quick googlefu myself (I don't care enough to do exhaustive search - especially if people are starting to be knobbers about it!! ) and I came up with this (random first page links to mention reasons WHY) … you will note there is no mention of valve clearances opening during NORMAL operation … http://faq.f650.com/FAQS/ValveMiscFAQ.htm
search for/click {What causes changes in Valve Clearances?} And another http://www.motorcyclistcafe.com/foru...read.php?t=191 (second post)

So once again, I put it to you to find some supporting evidence to the claim that inlet valve clearances open and I'll start to listen ... its going to take more than your mutual back slapping to convince me to the contrary of my own observation ...

Can someone who knows what they are on about (RobW#70 for example) please contribute to this thread, I’d take most of what HE says regarding bikes as dogma …

[yorkie_chris]

You miss my point, I don't really care either way, I've seen clearances open, I've seen them close, all I want to see is them back in the middle of their operating range.
No need to call me a knobber about it.

Originally Posted by yorkie_chris

You miss my point, I don't really care either way, I've seen clearances open, I've seen them close, all I want to see is them back in the middle of their operating range.
No need to call me a knobber about it.

Why the hostility then?

[yorkie_chris]

Was supposed to be in humour, honest

Originally Posted by yorkie_chris

Was supposed to be in humour, honest

Ha frekin ha!!!

[timwilky]

Now I may be talking out of my rear end here, and if this is the case please ignore as it may not apply to the simple SV engine.


Cam followers/buckets call them what you want, are designed to rotate within the carrier, this is to reduce wear, if they don't rotate a grove would be worn into the follower by the cam always rubbing against the same spot.

To induce this rotation, cams are very slightly tapered.


Therefore, you can expect there to be a minuscule difference between the gap when measured on the extreme ends of the lobes.

I have spent weeks using high speed photography to film cams/followers, seen the followers stick, seen the wear groves etc. Rotation is an important part of the cam system. It may just not be designed into the SV engine

[rictus01]

Originally Posted by timwilky

Now I may be talking out of my rear end here, and if this is the case please ignore as it may not apply to the simple SV engine.


Cam followers/buckets call them what you want, are designed to rotate within the carrier, this is to reduce wear, if they don't rotate a grove would be worn into the follower by the cam always rubbing against the same spot.

To induce this rotation, cams are very slightly tapered.


Therefore, you can expect there to be a minuscule difference between the gap when measured on the extreme ends of the lobes.

I have spent weeks using high speed photography to film cams/followers, seen the followers stick, seen the wear groves etc. Rotation is an important part of the cam system. It may just not be designed into the SV engine

Hmmm, never measured an SV valve to see (I'll do that next chance I get to confirm), but have seen the rotation effect on other valves, also seen the thermal effect on ceramic valves and the reduced effect of titanium light weight valves to control valve flow at high rpms, the benefits of additives in both fuel and oil on valve temp/wear and carbon build up is another area of interest to (done some practical testing myself here) all a bit techi stuff, but good to associated with witnessed engine wear.

However for setting purposes on the SV set the gap mid range not at either extreme, for those who don't understand the thermal dynamic wear characteristics and want to I could explain more simply* although I’d expect most to understand that the exhaust valve train will run upto 250’ F hotter than the inlet.

And Blue……. Posting for effect again.


*(PM me if you like).

Cheers Mark.