Broken valvspring.

[steve cowan]

Is there something to be said for too much spring and an excess of coil bind height?
It's been suggested here (and elsewhere) that's it's better for the spring to be operated closer to it's coil bind than it is further from it. Seems counter-intuitive in a way but might make perfect sense from a harmonic perspective.

FTR: I also had a 26918 fail. Use set although it was reunited with the same cam it started life with. Spring are circa 2005.

I was recently advised by the "local" guy who designed my cam to move away from the PAC 1219 and go with the 1218X instead.


Springs.jpg


Valve Spring Specs.xlsx

I run my solid roller springs at 0.050" from bind,if and when you go into float you want to minimise the distance the valve travels,it doesn't take much to widen the seat from bounce.
On combos that run tight piston to valve, coil bind would be pretty important I would think.

[Tom68]

I run my solid roller springs at 0.050" from bind,if and when you go into float you want to minimise the distance the valve travels,it doesn't take much to widen the seat from bounce.
On combos that run tight piston to valve, coil bind would be pretty important I would think.

High rate prings stop seat bounce.

That's loft you'd be fighting with close tolerance coil bind, loft is unlikely unless designed deliberately into a solid lifter grind, you'd never loft a hydraulic deliberately.

Running close to coil bind would be to try and minimise spring surge by deliberately smashing surging coils into each other, that doesn't sound like a good plan.

Best luck I had back in the late 90s with bad downshifting drivers was with Isky gold stripes with way more pressure than we should have needed.
Broke a Comp 959 back then but the spring was minimum requirement for the job and they were lower spring rate than advertised.

[Orr89rocz]

Mine was closer to .020-.030 to bind. Actual bind was abit less than advertised so my calculated .040 was not accurate. Also likely very minimal for the job at hand and honestly not sure they worked as good as i thought