what are the differences between self alligning and non self alligning rocker arms?

 

Factory style rockers are self-aligning and use a ball washer at the base of the rocker arm. Aftermarket rockers that are not of this design usually have "ears" at the valve end of the rocker, to keep the arm from slipping sideways off the valve stem.
Non-self-aligning use no method of alignment. They require pushrod guide plates. The guide plates keep the pushrod aligned and therefore the rocker arm.

 

Is there an advantage to using one type rather than the other?

 

For very high revving engines, the NSA are normally considered more stable.

 

Not to hijack the thread but I think this is along the same lines...
If you already have self aligning rockers (crane golds) and go to a big cam, will you need to change them to NSA rockers and get guideplates? Something like a 306 or 847?

 

You won't need to.

 

I was under the impression that if you use big springs on the heads that self aligning rockers won't fit. Is this true?

 

Please eloborate. I can't be the only one facing this. Anyone else with experience?

 

yeah , i'm getting the 306 and was trying to decide between the two. any suggestions?

 

Like Rob said, a NSA setup is stabler in the higher RPMs than a SA setup. NSA valvetrains need guideplates and hardened pushrods. For the cost, I don't see why anyone wouldn't want to go with NSAs. If you have a 93-95, the PRs are hardened already, so replacing them isn't necessary. Guideplates are around $25 (use none other than GM plates ONLY) and the NSA rockers themselves cost the same as SA rockers. And since you need to remove the rocker arm stud to install the guideplates, you might as well upgrade the 3/8" stud to ARP/Crane/Comp 7/16" studs.

I'm running Crane Gold 1.6 NSA rockers, GM guideplates, ARP 7/16" rocker studs, and Comp hardened high-energy pushrods.

Pic of setup.

 

do comp cams 1.6 NSA rockers require a longer pushrod?

 

No.

 

I think the issue is that many of us already have 1.6 Crane Gold SA rockers that we installed as a bolt-on way back when. As expensive as they were and replacing them with NSA rockers would also be expensive, many would prefer not to replace them. So the question remains - do we need to replace our SA with NSA rockers? And if the answer is maybe, please techincally explain why SA rockers may cause an issue.

Thanks!

 

ttt

 

I would not bother to change them to NSA, unless you are going to routinely turn over 6500 rpm or would like to feel better about the stability of your valvetrain.