When to Replace Valve Springs

[YL82]

Using a digital caliper, my valve spring measurements (free length) are as follows:

Outer Springs: 42.20 mm - 42.34 mm (Range)

Inner Sprngs: 41.1 mm - 41.4 mm (Range)

To check my measurements (to ensure I didn't compress springs for Free Length measurements, I set my caliper to 41.8mm and locked it, could not not get spring to fit inside caliper. Same for Inner Springs, I set caliper for 41mm, locked it and none of the inner springs would easily fit into the caliper jaws.

I'm nowhere near the 2mm wear limit (reduction in spring length by 2mm on any spring).

I do not have a valve spring compression rate gauge. Do I really need to get these compression measurements taken someplace?

Are valve springs normally replaced as a matter of common practice during a rebuild or only when out of spec? I sure don't want to unncessarily spend $100 or more on a new set of outer and inner springs.

Thanks.

 

[5twins]

Honestly, that's something I never checked or replaced. I don't think it's common practice to replace them, only if out of spec like you said.