Excessive coil bind

[rocketracer380]

Any issues with too much coil bind clearence

[blykins]

Depending on the combination, you could possibly get some coil surge at higher rpms.

[PackardV8]

Yes, no, maybe.

There's a reason most recent spring designs are beehives which stack the bottom coils.

I work with an obsolete engine which has a 1930s tall, skinny spring with lots of clearance between the coils. Above 4,500 RPMs, those OEM springs look like a slinky. Switching to beehives always picks up 500 RPMs with the same cam.

[MadBill]

The trend certainly seems to be towards running closer to coil bind to reduce surge potential, but there are a couple of possible issues I haven't seen discussed, e.g. lifter pump-up could potentially eat up all the clearance and I think some older design springs might not accept the near-coil bind loads without loss of #.

[user-17438]

you will have more issues not having the right spring rate VS too much coil bind clearance..

[PackardV8]

lifter pump-up could potentially eat up all the clearance

It's a separate discussion, but some here are of the opinion lifter pump up only occurs when the spring has lost control of the valve motion. Tight spring stacking may be less likely to go squirrley than tall, loose springs.

[cjperformance]

Has anyone listened to the Real Tuners interview with Tom Vigue on youtube. Its very interesting and does give some food for though on this very issue.

[cjperformance]

Has anyone listened to the Real Tuners interview with Tom Vigue on youtube. Its very interesting and does give some food for though on this very issue.

Well that killed this thread

[Scotthatch]

Slow motion video shows such amazing movement

https://youtu.be/yfmb-tCo2yA

One of the things about springs is that they will oscillate at a given frequency depending on material wire size and wind dia .... by changing the wind dia in the spring it means the different sections will oscillate at different frequency and give you a more stable spring ....

Having worked on all sorts of engines the only time I have seen lots of room between coils is in low rpm stuff so yes too much room does not help but on most high rpm high lift I am doing everything I can to get to fit so getting to much room is a little hard to make happen

[clshore]

Don't discount the damping provided by aero effects, combined with the effects of surface oil wetting.
The ovate wire used for many beehive springs enhances that effect, and extending the cross sectional
area with flat extensions, or intercoil material could take advantage of the natural pumping action to help
achieve better cooling of springs at the same time.

[groberts101]

Don't discount the damping provided by aero effects, combined with the effects of surface oil wetting.
The ovate wire used for many beehive springs enhances that effect, and extending the cross sectional
area with flat extensions, or intercoil material could take advantage of the natural pumping action to help
achieve better cooling of springs at the same time.

whoa.. you just blew my mind! J/K.. obscure and very interesting point though.