question on valve springs, RPM limits

[pjtoledo]

been reading some old posts on building a 3.0
in several places there are references to RPM limits on stock springs,
some say stay under 5500 and if you hit 5800 to replace the springs ASAP.
does that apply to all years? or do the beehive springs on the later roller cam engines tolerate those RPMs?


GO SLO! (huh, wtf?)

 

[Dirtman]

I'm no expert but being the 3.0 is already a relatively high RPM engine I'd think the springs would be fine, and I have never heard anyone reference problems with valve float on a 3.0?

 

[pjtoledo]

I'm no expert but being the 3.0 is already a relatively high RPM engine I'd think the springs would be fine, and I have never heard anyone reference problems with valve float on a 3.0?

from what I gathered it was imminent spring failure, not float, if over revved.

in all the years driving my 2000 I think it has only once seen 5K, and that took a while. it's still all stock.

 

[RangerGord]

Someone please correct me if i'm wrong but I think the straight and conicals have a very low seat pressure in our application. Although the conical springs should be able to tolerate float better and take more lift before coil bind, less weight, etc.... I think its a negligible difference unless you're living at redline all the time or have a heavily modified vulcan.

Edit: I'm stupid, but I really like this question. As intended our springs are good enough, but how do I know the rpm limit for my springs? All springs must fatigue, and our valves could even float around without hitting a piston, right? Videos of valvesprings in slo-mo are crazy and at my mileage i'm scared of 5800. How do I know my 290k springs arent jiggling around like jello for the brief time I spend above 5k.

Even mild forced induction builds have issues with springs, so we must be fairly close to the limit as is. Morana says his spring kit is necessary for the lift of a camshaft OR higher rpm and suggested for the 1.8 rockers, that's all I really know. I'd love to hear from someone who has been there already. A good way to know the limit is to break it, so kindly run it to 5800 and report back pls.

 

[pjtoledo]

Someone please correct me if i'm wrong but I think the straight and conicals have a very low seat pressure in our application. Although the conical springs should be able to tolerate float better and take more lift before coil bind, less weight, etc.... I think its a negligible difference unless you're living at redline all the time or have a heavily modified vulcan.

Edit: I'm stupid, but I really like this question. As intended our springs are good enough, but how do I know the rpm limit for my springs? All springs must fatigue, and our valves could even float around without hitting a piston, right? Videos of valvesprings in slo-mo are crazy and at my mileage i'm scared of 5800. How do I know my 290k springs arent jiggling around like jello for the brief time I spend above 5k.

Even mild forced induction builds have issues with springs, so we must be fairly close to the limit as is. Morana says his spring kit is necessary for the lift of a camshaft OR higher rpm and suggested for the 1.8 rockers, that's all I really know. I'd love to hear from someone who has been there already. A good way to know the limit is to break it, so kindly run it to 5800 and report back pls.

we need results fast! just downshift to first at about 60. that should put the springs past their limit.

 

[RangerGord]

I tried but no matter how hard I throw it into 1st it just waits until I slow down. I manually shift in and out of the driveway now, but everyone at home still makes fun of me for my tiny left leg.

 

[Dirtman]

Springs is goes boing.