Are valve springs w/ dampers less senstive to clearance from coil bind at max lift?

[BradH]

I was checking the max lift vs coil bind specs for a variety of dual springs (PAC, Manley, Isky) and quite a few of the dual w/ damper springs had max lift ratings that were .100"+ from coil bind. However, some of the dual w/ damper springs were spec'd down in the .050-.060" clearance range, and all of the duals w/o dampers were as I recall.

It gave me the impression that having a damper -- although it has its drawbacks -- makes the distance to coil bind less critical. True? Or is my observation more likely to be applicable to certain springs & applications?

Thx - Brad

[novafornow]

Noticed something along these lines as well. Interested in the responses.

[PRH]

Brad....... just pull out the stops and go for the dual conicals.

[BradH]

Brad....... just pull out the stops and go for the dual conicals.

I thought about that seriously... right before the killer deal came up on the Isky/PSI dual w/damper spring sets.

Got into multiple sets of Isky's and the rest of the hardware to run 'em for less than the dual conical springs < drool > alone.

IIWII... now I just want to know what makes sense for setting up the installed height after I verify the net loaded lift.

[BradH]

Bump 'cuz I'm still hoping to get some feedback on this. I got a set of heads to assemble this weekend...

[ProPower engines]

Personally I refer a taller spring to get decent clearance between the coils.
Springs do funny things when the rpm is in the upper ranges like over 5500 to 8500 and I have seen evidence of a wave action in the coils where they would rub at tighter clearance causing breakage making a good day go bad fast.

I have used Isky springs for over 30 yrs and never broke any to date but have seen other brands break using the same
theory.
I talked to PAC about an issue I had a while back and while they told me to run the spring tighter to solve the issue
with using their spring and run it closer @.050 from coil bind .

Cam profiles can play a big part in valve spring life and when doing a R+D project that can be very informative as you
learn what works and what breaks stuff, just part of the fun