Originally Posted by
Kyle Higher spring rate typically means shorter spring. (not always)
Higher spring rate valve springs can be any length.
Originally Posted by
Kyle Just like with lowering springs, the stiffer they get, they usually get shorter as well. (not always)
Bad analogy. Valve springs are different than suspension springs. They have different design purpose.
A suspension spring that is stiffer( higher rate) than stock needs to be shorter if you want to have the same ride height. The ride height is the main consideration for the spring length.
The valve spring dimension is the result from careful consideration of the camshaft lift, aggressiveness, rpm,and boost pressure. Some higher rate valve spring can be taller than the factory spring because of the danger of coil bind (bottoming) due to the higher lift camshaft.
Spring rate is affected by, material of the wire, wire diameter, spring diameter, and coil #.
If you look at the pics, the Franklin’s springs have bigger wire diameter.
Originally Posted by
Kyle When you compress an object with X amount of energy, it has to be released with some sort of relationship. Differences are in material, and how the spring itself is made along with normal stacked tolerances. If you take the same length spring, but one has 100 lbs/in of force and the other spring has 400 lbs/in of force the spring with 400 lbs/in will exert a much larger force than the same length spring at the weaker rate of 100 lbs/in. That force being exerted needs to be controlled, somehow or it will harm the valvetrain in some way, shape or form. (just like lowering springs that are long and stiff will blow out a damper faster or simply age the damper at a quicker rate of pace than a properly matched set)
Yes?
Again, a bad analogy. You can’t compare valve springs with lowering springs. The lowering springs have dampeners(shocks) to control them. The valve spring has no such thing. It job is help the valve follow as closely to the profile of the camshaft as possible. The higher rate valve spring does a better job of this.
Spring rate is very easy understand.
If it’s rated at 100 lbs/in, it means it will take 100 lbs of weight/force to compress it 1 inch.
If it’s rated at 400 lbs/in, it would take 400 lbs to compress it 1 inch.