If you are talking very high hp the major issue is having a cam, valve, and follower strong enough to open the exhaust valve against ultra high combustion pressures. Many a valve stem buckled and rocker arms destroyed trying to open the exhaust valve too soon.
Also some talk about seat pressure. The spring only implies a force. Pressure in this case would be on the contact area between edge of valve and seat? Others talk of back pressure on the valve back face that can reduce closing pressure.
Which one is it? Seat force exerted by the spring? Pressure on the back face? Pressure on the combustion face?
Ps remember when jpc changed over to studs on the cam holders? Is that still an issue?
Great thread op, this is enlightening.
We have not used those studs in some time now.
i think all your questions play a role in to what spring to use
For a 500-600whp NA build that's stable to 8000+ RPM, preferably retaining full VCT operation range, would the Trickflow #1 or the Livernois be the best option?
Either one will work :rockon: