Agustin Deltoro

I'm having trouble understanding how to choose the proper set of valve springs depending on the camshaft. For instance for a 289LRR HR14 Hydraulic Roller Cam, that has an 0.624 Lift, 239/255 int./ext., LSA of 114. How would I know what rating I should use?

Tuskyz28

Most quality springs is rated are rated for 650 or more on the lift.

99 Black Bird T/A

iTrader: (4)

My quick Google search suggests that Comp Cams says use their dual 26926 springs. I would probably use Comp 's spring kit.

If you're wanting a different spring, I would keep the specs for this spring in mind.

Comp Cams 289LRR HR14 - springs

Agustin Deltoro

Thank you guys. So from what I'm understanding any spring should work, whether it be beehive, conical, dual or single. But how does lb rating relate to the camshaft?

Tuskyz28

Always go double if you can. Ive seen double valve springs save motors from a catastrophic failure.

Agustin Deltoro

OK, so how do I go about choosing the rating?

G Atsma

This might be considered copping out, but call the cam grinder and get their recommendation for that cam AND your setup. This way you can't go wrong.

RB04Av

The more aggressive the cam - specifically, the faster it drops the valves onto the seats when they close - the more likely they are to bounce, aka valve float, and therefore the more spring they need. Look for springs that give AT LEAST the same seat pressure as the cam mfrs' recommended choice. It's hard to have too much seat pressure.

However, the more aggressive the springs are - in terms of pressure at full open, aka over the nose - the more likely they are to tear up the cam, and the more the cam needs to be made of the best possible materials and the best processing. (hardening, via heat treating)

A great place to start is with the cam mfrs' recommendations; look at what they think it needs, and go from there. Comp also has many of their cam series listed in their catalog with a "base" and "upgrade" spring; using the "upgrade" is always better, if there's a selection for this cam. Likewise, as you look down a series, you'll see they use the same spring for a few, then jump to another and use it for a few, and so on... if the cam you pick is ANYWHERE NEAR that dividing line, best to step up to the next choice.

You can also look at similar cam profiles from other mfrs that spec other brands of springs, and use the same disciplines on those.

The spring 99 posted looks to me a good match to the cam; no surprise really. Another possible choice would be the 1221X, here. https://www.texas-speed.com/p-5040-p...pac-1204x.aspx There are others as well of course. But I'm sure you get the general idea.

Agustin Deltoro

Thank you very much.