RallyBoy1

I really want to know what makes non self aligning better than self aligning rockers. If the nsa's are better than sa's, why didn't the factory use them? It seems that the use of the nsa rockers and guideplates would not be ideal for a car that is used as a daily driver that sees 25k plus a year. I know there are many people who recommend the use of nsa rockers, but I wonder how many people just recommend them because they heard Joe Blow say that he uses them? When do sa rockers become an issue?

shoebox

NSA are more stable at higher RPMs because they correct the alignment on the pushrod side. The stock NSAs are cheaper to manufacture and the high RPMS are not that much of an issue for a stock engine.

Green96Z

The adjusting tabs on the SA rockers also have a habit of breaking off at high RPMs.

RallyBoy1

It seems that the SA tabs would provide a better alignment since the rocker is always centered on the valve. I have never heard of the tabs breaking off due to high rpm or or any other reason; although I could see that as a possibility.

shoebox

There are more forces working against good alignment at high RPMs with SAs than with NSAs. NSAs correct alignment before the rocker could get out of position and even need the alignment tabs that SAs have.
SAs have to correct the motion caused by the pushrod and subsequently the rocker. That's going to be harder to do, the higher the RPM.

RallyBoy1

Would NSA's benefit me if I only plan to spin to 6000-6200 rpm? Thank you gentlemen for your responses. Anyone else have anything they would like to add?

blue 79 Z/28

in addition to the points above, severe enough valve float a SA rocker and you could find yourself with a rocker not on the valve anymore. also SA are only compatible with zero lash setups, nothing mechanical for future upgrade options. you are also limited with the type of springs and retainers you can use and valves. its really only a replacement entry level mod IMO. anytime internal upgrades are gonna be made id recommend going the guideplate rocker route. there is really no negative to running a guideplate, they have been used that way in GEN I sbc for years and years. if theres proper valvetrain geometry you will have trouble and wear free valvetrain for as long as everything else will last. one note, you need hardened pushrods for guideplates, other then that good to go.

BUBBA

The reason you need to use hardened push rods with NSA rockers and quideplates is because if the non-hardened prs rub against the quideplates they could get worn and thus bend, break, etc. So...if the prs are prone to deflect and rub against the guide plates, there will be some friction, which which negates efficiency in the valve train and creates heat which is also detrimental side effect.

I don't know if this is correct, but it seems logical to me. Had I known that NSA setup is "superior" I probably wouldn't have gone with Crower $$$$ SS SA, RRs. I doubt that I wiil switch at this point since I have a baby cam.

So your NSA setup may be better, but mine cost more.

blue 79 Z/28

i run a jesel on my LT1 and a T&D system on my gen 1 sbc. the ultimate and most costly rofl

truedualws6

I could be full of BS on this but it seems that SA rockers are only available in 3/8" whereas 7/16" is the norm for high performance applications. So if you you are using 7/16" studs you don't have a choice.

ACE1252

Shaft mount rockers?

blue 79 Z/28

yes

RallyBoy1

Bubba, you make a very good point.

Don 97 SS

Well, one of my $$$ Crower SS SA failed and jumped off my valve. The result was a destroyed engine. No more SA RRs for this guy.

BUBBA

Don: As you know I had the same problem, however, I don't know why and I have never heard anyone give an answer to that question. Having said that----if they were prone to do that, I am pretty sure that we would have heard alot more about it, since it would very well ruin an engine if the valve dopped onto piston. I think that I will contact Crower some time today and ask them for their opinion or experience.