Spring dampeners...needed or not?

[travis]

On a mild HFT cam application with corresponding mild pressure single springs...is a dampener spring necessary? Some springs have them, others don’t. I’ve used both over the years many times and never noticed a difference either way. I do remember reading something a long time ago that a dampener reduces spring pressure requirements somewhat by controlling the spring better.

I’m curious what y’all’s thoughts and experiences on this are.

[BlitzA64]

Many newer design springs don't use dampers they build heat and cut into stuff, I hate them. I use whatever is out there that doesn't have them and never had an issue street or race

[Caprimaniac]

Double springs. Same rating. One with, the other without, a dampner spring.

Spring mass (w/o dampner) and thread diameter identical.

So, spring w/o dampner will have less mass in action.

Which one will do a better job controlling the valve?

[mag2555]

Every spring set up be it single or triple has a rpm range where it looses control of its own mass, and when that takes place it looses control of the valvetrain also!

Even some duel spring set up's have been seen to have this issue at only 4000 to 5200 rpm, showing a loss of 12 hp even with a mild Cam.

Just stay away from the so called dual springs that have only a flat wire type inner damper if your going to run over .450" lift, as these dampers fail a lot by unwinding themselves thru the outer spring,and when they do 95% of the time the motor dies from a dropped valve, it's not pretty!

Also flat wire dampers work by means of friction and as such kick up oil temperatures also.

These days if your running a SBC, BBC or SBF and your not running a atleast a Beehive or better yet a Conical type spring then your far behind the cutting edge !

[Walter R. Malik]

A damper is there to help control surge and oscillations during running.

Those always happen but, sometimes not to the extent where a damper is needed.

Usually with a counter-wound double spring, they tend to dampen each other as they have different frequencies.

[LSP]

Many newer design springs don't use dampers they build heat and cut into stuff, I hate them. I use whatever is out there that doesn't have them and never had an issue street or race

X2

[Dan Timberlake]

1958 Chevrolet tech.

348 spring damper .png

Several years earlier Studebaker good naturedly described their V8 development.
Attached is what they had to say about valve spring blues.

v8 valve bounce.png

[rebelyell]

Last iteration of SBC (perhaps best ever) was iron head rpo L31 Vortec.
It has a Single Valve Spring with No Damper; about 75-80 lbs on seat.

[Caprimaniac]

These days if your running a SBC, BBC or SBF and your not running a atleast a Beehive or better yet a Conical type spring then your far behind the cutting edge !

I am quite happy to remove my duals w/ dampers as they dug into the precious Ti retainers. However, didn't do any real damage.

Your statement on conical & beehive springs is abit far fetched. Why? Because moving into cam profiles in need of 200+ seat gives very few options on suitable con & bee springs. Comp has one double conical that could suit my racecam (250 seat), but looking at the specs, I figure a PSI- spring (trad double) will Equal it's potential.

Also- this has been disucssed alot- using a double spring VS a single beehive/conical give some advantages if a a spring should break...

[Rick!]

Usually with a counter-wound double spring, they tend to dampen each other as they have different frequencies.

I think it's more due to each spring having its own surge frequency that does not align with the other spring's surge frequency. Unless they physically rub on each other, damping is usually not achieved.
Springs, being a fundamental motion device, do not have any damping characteristics unless the design allows several coils to come into contact with themselves during operation, i.e. friction damping. It still leaves the coils not in contact to vibrate at their own natural frequency (sqrt(K/m)).

[Kevin Johnson]

Counter-wound springs will help dampen each others torsional extensional rotation.

[BOOT]

Floated an engine bad once and it broke almost every one of the dampers