So do you exprience valve floating on high revs?
All About Valve Springs! (with nice pics)
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So do you exprience valve floating on high revs?
- Joined
- Sep 28, 2013
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- Poznan, Poland
I don't know anything about the valve floating because I can not see them when I ride
I don't have tachometer so I don't know how high the motor revs right now.
I like to ride at high rpm's and did not notice anything wrong.
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- south east WA Australia
Just to clarify;
nobody has anything to worry about with any of the dual springs available if they are installed in a stock head 04 up with stock valves
they all have adequate seated force (more than 60lbs) to prevent valve issues
the Kibblewhites want 7mm preload or a tad more (0.1 -0.2mm) for 75 to 80 lbs seated. installed height as per instructions (attached) is 1.170"-1.180"
if you require more than 10500rpm and suffer internet induced anxiety just use the additional spacer under the main thick Kibblewhite lower spacer, its OD locates in the head recess and the thick spacer locates itself on the valve guide, (see PDF instructions below) the KW springs with the added preload will still take less power to run than the others
the lowest force you will get out of Taffys in the same head is 76lbs with a 0.1mm shim (bad idea)
the ATV set is 80lbs seated
the oem conicals are 72lbs seated
In case its still isn't clear they are all about the same seated and are all perfectly adequate for the job except for the oem single springs which often break near 200hrs
the difference is in power required to run them (kibblewhites win) and pricing is the main difference between the other 2 dual sets
Item # 96-96000, Lightweight Racing Valve Spring Kits for KTM® All RFS Engines 450cc-525cc 2008-2009 On Kibblewhite Precision Machining
cheapest usually on ebay search for kibblewhite 9696000 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=kibblewhite+9696000&_sop=15
nobody has anything to worry about with any of the dual springs available if they are installed in a stock head 04 up with stock valves
they all have adequate seated force (more than 60lbs) to prevent valve issues
the Kibblewhites want 7mm preload or a tad more (0.1 -0.2mm) for 75 to 80 lbs seated. installed height as per instructions (attached) is 1.170"-1.180"
if you require more than 10500rpm and suffer internet induced anxiety just use the additional spacer under the main thick Kibblewhite lower spacer, its OD locates in the head recess and the thick spacer locates itself on the valve guide, (see PDF instructions below) the KW springs with the added preload will still take less power to run than the others
the lowest force you will get out of Taffys in the same head is 76lbs with a 0.1mm shim (bad idea)
the ATV set is 80lbs seated
the oem conicals are 72lbs seated
In case its still isn't clear they are all about the same seated and are all perfectly adequate for the job except for the oem single springs which often break near 200hrs
the difference is in power required to run them (kibblewhites win) and pricing is the main difference between the other 2 dual sets
Item # 96-96000, Lightweight Racing Valve Spring Kits for KTM® All RFS Engines 450cc-525cc 2008-2009 On Kibblewhite Precision Machining
cheapest usually on ebay search for kibblewhite 9696000 http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&_nkw=kibblewhite+9696000&_sop=15
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- Nov 23, 2012
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Thanks!
A minor followup question: Is there any drawback to the 7mm preload? I don't expect it to be but good to have it confirmed
A minor followup question: Is there any drawback to the 7mm preload? I don't expect it to be but good to have it confirmed
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I do not have so much free time on my hands that I can keep up with all threads, or even being able to contribute when I feel it concerns a field in which I have made lots of mistakes (so called experience). So when I finally stumbled over the interesting subject of valve springs, I had to read it! The subject of mechanical springs is very wide and somewhat complex. This thread only partially concerns the theory behind the design, measured physical specs and proven results. Harsh words and humiliations took however this promising thread to a level unworthy of UHE. So I just wanted say I'm a little sad over this, and I hope professionalism and a humble tone will return to the forum. [emoji17]
I have used both OEM springs and special PAC-springs.
Yours Dr_C, allways on the technical barricades, eager to learn more!
I have used both OEM springs and special PAC-springs.
Yours Dr_C, allways on the technical barricades, eager to learn more!
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Thank you. I will take this to heed.
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Hey a question - what is the field of engineering theory called that valve springs fit under? And can anyone recommend some reading material? Academic stuff from engineering welcome if you have it!
Probably there's something on valve springs in Tuning for Speed and other stuff that's been recomended before - will probably appreciate / get it better now
(While it can be tricky to read general material from an academic discipline that one is lacking a background in, it's good to try to dig into the maths/theory/ideas of a field that is already on the mind amd being puzzled over)
Probably there's something on valve springs in Tuning for Speed and other stuff that's been recomended before - will probably appreciate / get it better now
(While it can be tricky to read general material from an academic discipline that one is lacking a background in, it's good to try to dig into the maths/theory/ideas of a field that is already on the mind amd being puzzled over)
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Here is one source:
http://www.amesweb.info/MechanicalSprings/MechanicalSpringCalculators.aspx
For more in depth discussions, specifically concerning the application we are interested in, you may find some useful threads on the topic in the forum "SpeedTalk".
http://www.amesweb.info/MechanicalSprings/MechanicalSpringCalculators.aspx
For more in depth discussions, specifically concerning the application we are interested in, you may find some useful threads on the topic in the forum "SpeedTalk".
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read the first page of this topic
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KW are smaller outside diameter and shorter than all the others so generally dont require any work to the head or valve cover to be fitted as per the maufacturers specs to any of the husaberg engines.
the other sets are bigger OD and longer
the other sets are bigger OD and longer
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- Aug 15, 2016
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- NSW Australia
Absolutely, I was thinking I'd have to relieve a bit of head material to fit my Kibblewhites but they went straight in no mods at all. The only hold up was admiring those titanium retainers! Very happy with them and personally wouldn't bother running anything else.
Damo
Meanwhile I received the KW springs. I´ll have time next week to do the job and change the valve springs. Which special tools do I need (except for valve clearance needed)? Do I need a spring press? Do I have to take off the head or can I leave it installed?
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If you have access to an air compressor, after removing the spark plug, you can use a fitting to connect the air hose to the plug hole and hold the valves in place. That way the head stays on. Will need a special lever or proper valve spring compressor to be able to remove the collets though.
If the head is off, I just used a crude method of a large g clamp with a piece of tube and a window cut out of it. I reckon I would've even impressed bushy with this method....
Or you can be professional like and just use said valve spring tool.
Once the collets are back in, tap the top of the valve with a copper hammer or similar to double check everything has seated nicely.
(Sorry plumbbob, not trying to undermine you mate)
Good luck
Damo
If the head is off, I just used a crude method of a large g clamp with a piece of tube and a window cut out of it. I reckon I would've even impressed bushy with this method....
Or you can be professional like and just use said valve spring tool.
Once the collets are back in, tap the top of the valve with a copper hammer or similar to double check everything has seated nicely.
(Sorry plumbbob, not trying to undermine you mate)
Good luck
Damo
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No worries Damo, the compressed air in the compression chamber sounds like a time saver.
Just don't drop a valve collet down by the cam chain Duc851
Haha indeed, unless you like using profanities!
Because you know it won't just gently fall to the bottom of the cover. It will have to get stuck somewhere inaccessible halfway down right!
Damo
