@trumpetb said in Valve Springs:
Ok
First point,
springs are made of spring metal that upon deformation will return to its original position or length.
In the case of a coil spring, the spring will return to its original length if the spring when deflected has remained within its elastic limit.
If however the spring is extended beyond its elastic limit it enters its plastic phase and will no longer return to its original length.
The spring having deformed to a new length will then have a new and greater elastic range.
The result is the spring behaves as it did when it was its original length and can be expected to give a normal life but with different characteristics.
Of course stretching a spring manually is a somewhat hit and miss process and is subject as you say to variance on a case by case basis.
The principle of deformation in the plastic range producing a permanent change in the length however holds true.
But also the change in K holds true. In this situation, K wins. Rowuk is spot on with his assessment.
However, there is a solution. Buy a new spring and do keep it intact this time. This will make things O"K" again.