PSI valve springs

[evofatboy]

I like the idea of beehive springs but am afraid of what happens when one fails. I want to use a Redshift 626v cam in my S&S 113v. I have read where Bob Woods uses PSI valve springs. I came across the LS1516ML beehive spring which sounds like a good fit for Evos. 150# seat pressure and 1.800 installed and good for .660 lift. Unable to find info on what collars,keepers and locators to use with the to fit the springs. Anybody using automotive springs from PSI on their Harley engines?

[Don D]

Everybody uses automotive hardware. Just measure up the dimensions and get into Kibblewhite, Comp, PAC racing, or Manley catalog and find what you need. My recommendation would be a dual without damper flat spring, not a beehive, a smaller diameter spring than BBC which are 1.500+ OD. I have had all of the beehives break including PAC x series. These were extreme conditions I admit, guys running cross country at high speeds with .650+ lift.

[nibroc]

running cross country at high speeds with .650+ lift is lookin for trouble

[Burnout]

running cross country at high speeds with .650+ lift is lookin for trouble

Need to squirt some oil at those springs to keep them cool.

[Rsw]

running cross country at high speeds with .650+ lift is lookin for trouble

Why's that?

[Burnout]

Not a problem if you carry extra valve springs with you...

The reliability curve drops off above .500" pretty steeply above .600"

[kd]

Not a problem if you carry extra valve springs with you...

The reliability curve drops off above .500" pretty steeply above .600"

Do you have any reference (as in durability charts) from valve spring manufacturers to support that?      I haven't seen one. I am of the opinion that the weight of the spring (work load) would be a deciding factor if you push them to where they work out of their range.  Properly set up for the travel (.650 lift) they should be no different than a similar spring set up for a .500 lift The only difference is .015 (plus the rocker ratio calc) travel if the weights and wire clearances are similar.  The stress would come from working past the weight they (the wire) is / are designed to work at. 

IMHO, properly set up there should be nearly no difference.   The emphasis is on the setup weight and range they are working in.

I do feel using double springs in all situations is better. Manufacturing defects that can not be detected are more likely to be the problem and having the double spring assembly gives a small window to save a catastrophe from occurring. Seeing the reliability curve you reference could be helpful in planning longer engine life.

[build it]

eeek

[Don D]

I have customers that put miles on bikes with .650+ lift cams successfully. Not my bag, my bike has .550 lift but it is nearly stock also.

Many factors need to be right, the geometry, and a cam that doesn't have lobes that open and close with such intensity that this causes the need for extreme spring pressure to control the valves. Now you have exceeded the capacity and design of the hydraulic roller lifter and it becomes the weak link. Very large pushrods become necessary also. There are cams out there that have closer to what I would call an industrial cam lobe as opposed to a jack hammer. They are not cutting edge. But remember cutting edge is right next to bleeding edge.

[Burnout]

There is no "durability chart" too many variables.
Especially cam profile, some cams are more gentle.
The geometry needed to create high lifts is not gentle.

The numbers I quoted are tribal knowledge generally applicable to most pushrod valve trains.
I know for sure that if you are going to punish valve springs you need to pour oil on them to cool them and dampen oscillations.

https://www.youtube.com/watch?v=50F-haEs3pg

Of particular interest is the "slinky" like oscillations and how the valve stem wobbles around

Here is another  https://www.youtube.com/watch?v=WtqDHJDN79w using stop motion strobe lighting

[Hossamania]

Interesting videos. It's hard to fathom that there is enough time between events for them to move that much.

[Ohio HD]

Because you do go over 0.600 lift is not a guarantee you'll have spring issues. Does the chance become greater? Maybe. I do know some members here that have used T-Man 0.660 and S&S 640 lifts and have over 80k Miles. RPM that the motor is run in has a big impact on longevity and potential for failure.

[Chippitt68]

The second video is at 8500 rpm.

[kd]

Great conversation.     Burnout, I have seen those videos. Great stuff. 

I personally am at 660 lift (Tman 660sm).   The ramps are not severe and when Mr Baisley did the heads he removed the MVA springs   and chose another double spring (w/ valves, guides, and corrected rollers) set to provide high rpm control with less weight than the excessive SE springs. The reason was to allow reasonably abusive higher rpm control, and better reliability for long day touring geared at 3.16.  Our discussion previous to the work explained (readers digest version) that the issue of spring choice for reliability was dependent on several factors in the set-up. The lift, although a factor, was not as big a big concern as spring weight and cam profile etc.   It made me more comfortable with my choices.  As Ohio said,  there are plenty of folks at the 640 to 660 lift level putting on lots of miles. I am not one of them (yet) but I have been punishing it.      I suspect it's good set-up work that allows that.     

[Burnout]

You should see the springs on the drag motor I have been helping on, .900" lift.
I don't see how they are going to hold up.
I am convinced it's a grenade.

[Don D]

>.600 lift does not guarentee punishing lobe intensity however there are some that go there.

[Hillside Motorcycle]

On the other side of the fence, we use a lot of Kibblewhite/Precision Machining or AV&V .650" beehives.
Same/same spring(AV&V) that is offered in the S&S Super-Stock heads.
Have yet to see a failure.
Have witnessed OEM HD beehives fail in even OE applications.