Titanium Valve < Spring Pressures

raceman14 · 12-10-2010, 01:24 PM

Mike,
Your question on valve springs, pretty much depends on the quality of the hydraulic roller lifter you are using and where it starts to lose ability to hold hydraulic pressure.

Most folks think once they are pumped up they stay that way but after many hours on the spin-tron, we learned they bleed pretty bad at high rpms. Most of the work was done for GM 604 Oval track crate engines but the theory applies to any hydraulic lifter.

I have some super nice PSI springs designed for the application along with matching roller hydraulics for .842 lifter bores & Chevy Tie bars. Set-up height is in the 1.850-2.050" / .600-.800" lift. This package is 125-150# on the seat depending on the set up height. This package is worth about 1000rpm and 15-20HP on a Stock 604. More cam and more head flow makes a greater difference.

It is a delicate balance kind like balancing a see-saw with the spring pressure on one end and the hydraulic lifter on the other. I can tell you that valvetrain stability is worth 10-20% RWHP increase on hydraulic lifter engine.

MontyF · 02-24-2012, 11:56 AM

Quote:

Originally Posted by raceman14

Mike,

Most folks think once they are pumped up they stay that way but after many hours on the spin-tron, we learned they bleed pretty bad at high rpms. Most of the work was done for GM 604 Oval track crate engines but the theory applies to any hydraulic lifter.

It is a delicate balance kind like balancing a see-saw with the spring pressure on one end and the hydraulic lifter on the other. I can tell you that valvetrain stability is worth 10-20% RWHP increase on hydraulic lifter engine.

I have a few questions concerning what you found.

So according to your tests the issue is bleed down instead of pumping up?
Can this be avoided by limiting lifter plunger travel? I'd assume as the spring loses control of the valve train, so the lifter is unable to follow the cam, pump-up is still possible?

James L Miller · 03-05-2012, 12:42 PM

You can calculate the change in spring RATE using the following formula:

w0=SQRT(k/m)

where w0 is the natural frequency of oscillation (valve float)
k=spring rate
m=mass of valve, part of the spring and retainer and lock.

http://en.wikipedia.org/wiki/Damping

12-10-2010, 01:24 PM	#1
raceman14 Junior Member Join Date: Dec 2010 Posts: 3 Likes: 0 Liked 0 Times in 0 Posts	Re: Titanium Valve < Spring Pressures Mike, Your question on valve springs, pretty much depends on the quality of the hydraulic roller lifter you are using and where it starts to lose ability to hold hydraulic pressure. Most folks think once they are pumped up they stay that way but after many hours on the spin-tron, we learned they bleed pretty bad at high rpms. Most of the work was done for GM 604 Oval track crate engines but the theory applies to any hydraulic lifter. I have some super nice PSI springs designed for the application along with matching roller hydraulics for .842 lifter bores & Chevy Tie bars. Set-up height is in the 1.850-2.050" / .600-.800" lift. This package is 125-150# on the seat depending on the set up height. This package is worth about 1000rpm and 15-20HP on a Stock 604. More cam and more head flow makes a greater difference. It is a delicate balance kind like balancing a see-saw with the spring pressure on one end and the hydraulic lifter on the other. I can tell you that valvetrain stability is worth 10-20% RWHP increase on hydraulic lifter engine.

03-05-2012, 12:42 PM	#3
James L Miller Member Join Date: Apr 2005 Posts: 494 Likes: 6 Liked 25 Times in 16 Posts	Re: Titanium Valve < Spring Pressures You can calculate the change in spring RATE using the following formula: w0=SQRT(k/m) where w0 is the natural frequency of oscillation (valve float) k=spring rate m=mass of valve, part of the spring and retainer and lock. http://en.wikipedia.org/wiki/Damping __________________ Mopar 2 Ya!