Joined Sep 2007
782 Posts | 291+
???
Taffy, just had another look nothing written on mine. You could make a simple jig to hold the inner and outer spring sitting on the base washer, a pin through the middle, the titanium retainer on top and apply 75lbs weight. Then measure the spring length. Cheers spanner
Joined Jun 2001
1K Posts | 0+
Pasadena Ca.
Taffy said:
Taffy,
The bottom row of washers in my photo are the custom base washers (bottom cup) Dale had made for the Husaberg. You have been talking about the Kibblewhite kits, well the Husaberg head has a larger diameter spring seat than the KTM does, so regardless of where the rest of Dale's kit came from, he had to have spring base shims made to fit the Husaberg head.
Just to clear the air, Dale's "Installed Spring Height" value is the space available for the Outer Spring. This space is adjustable by adding shim spacers under the bottom spring cup. See the first paragraph in the 'How To Obtain The Correct Installed Height'
This is to compress the springs the necessary amount to get the desired valve seat force.
Joe
Hello. On my Kibblewhite ktm 450 2003 kit it say installheights between 29,97-30.22MM, and I think it should be the same on husa because they use the have the same spring(part nr) as oem.
Regards Patrik
Regards Patrik
Taffy said:
Well there you go Taffy your valves are longer hence the 3mm taller spring height. Just knock up some 3mm spacers and you should be OK, I new there had to be difference some where because mine Kibblewhite springs measured up perfect.
Sparks.
Taffy said:
I wonder if Engine hardware could comment on this he has been using them for a few years.
Regards
Sparks.
sparks said:
"No comments onthe length", but when we install the springs we dont get the correct lenght with the shimm/washer that comes with the kit. We get 30.6mm total length with a std husaberg cyl head, no diffrence on inlet or outlet. We have tried a thicker washer but we see no gain. We just run them with this lenght, they are then just a fraction softer due to less tension, but we dont have any broken spring anyhow.
We was worried in the begining some years ago but since it worked we dont bother to adjust the total spring lenght when installed, below 31mm is ok for us.
When we get the cyl head with new titanium valves we could adjust the clip grove a bit but we havent had any trouble so we leave them stock position.
//Thomas
Joined Jun 2001
1K Posts | 0+
Pasadena Ca.
Taffy said:
Taffy, it sounds like Dale Lineaweavers kit has different springs in it than the ones you are working with.
The method of determining spring strength,(ie. spring rate) is to place the spring tester and test it.
Its kind of like a drill press with a scale mounted on it. Set the spring on the scale, come down on the spring with a cup fixture in the drill chuck until making contact with the spring and setting the drill press distance gage to zero and then compressing the spring a set amount, maybe 0.100", and record how much force is on the scale at that deflection.
That would give you the spring rate in pounds per inch.
As for installed spring height, you want a certain spring pressure on the valve when the valve is closed. So you compress the spring the amount that will give you that pressure. This gives you the installed spring height.
That should answer your question.
That is of course, just an explanation to answer your question. The process of designing a spring set for an existing engine includes staying within the engine existing design parameters, of overall space available for the spring and spring retainer in the engine and the valve lift determined by the cam profile and the rocker arm design.
In Dale Lineaweavers kit Dale did his best to make use of the available space. This included light weight Titanium spring retainers of an optimum design to fit within the Berg head and cam cover, provide proper seat pressure, limit spring pressure on the nose of the cam and still provide adequate over rev without valve float.
His kit is good for 10,500 rpm using OEM steel valves and greatly reduces cam nose pressure from that of the OEM conical valve springs.
Plus the fact they are dual springs. I swallowed a valve in my 501 when an OEM spring broke from fatigue. If that had been a dual spring set up I would only have had to replace the valve springs instead of all of the engine work required to repair the damage.
Joe
Race engine no 1 we have 40/34 and the second that is comming together now 38/32.Taffy said:
These i can messure when i get the cyl head back from re-doing the grove on the valve shaft due to that we have to use lashcaps, because the shaft is not coated, and then its to soft.
//Thomas
Taffy said:
On a small 350/400 engine these small valves are OK, for a female riding style.
With a big volume engine for us heavy lads, we recomend 40/34 Titanium valves.
Sleep well.
Thomas.
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