| :or hard headed. Don't pretend like you have never personally attacked my intelligence. You're right, but you usually pull the trigger first, as in this case Valve bounce on the seat is caused by insufficient valve seat pressure by the spring. Having a lighter retainer is not going to change your valve seat pressure. By the time the cam gets close to closing the valve, it has slowed down so much that retainer weight will not affect it much because of the ramp closing rate. Sounds reasonable, but people routinely take their engines to 7500RPM with stock springs with no repercussions. This tells me that seat pressure is not the limiting factor here. In fact, JWT has said off the record that the 400+ cam is ok with stock springs, provided 7500RPM is not exceeded. I hear what you are saying about valve bounce, but the fact is a heavier valve will bounce harder. I think this is more of an issue with domestics with the much heavier and larger valves. You want a lighter spring? Lighter than what stock? What I meant here was lighter than the JWT spring, as indicated in my profile. You really should have asked for clarification before assuming I'm an idiot I admit I made blanket general statement. But I made it with what is available on the market. Crower or Ferera make 250 lb + valve springs for the VG30DETT. The Tomei and JUN springs check in under that around 175 - 180lbs which are slightly heavier than stock. Just because you use Titanium retainer does not mean you will use a lighter spring. That depends on what the limitating factor is...is it valve bounce, or valve float (where the valve no longer follows the cam lobe profile) The cam itself determines how heavy of a spring to use. If it is an aggressive high lift ramp rate, you need a heavier spring to keep the lifter on the lobe at high rpms. This is where a lighter retainer will help. A lighter valve assembly requires less spring to keep in touch with the lobe It's not rocket science but basic cam upgrade logic. I am using JUN valve springs which work great for under 8000-8500 rpm according to JUN.
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