Any advantage to the aluminum rocker spacers in lieu of the stock springs? For the price (~$20) seems like a no brainer if there is any advantage at all?

I don't get it. What is a rocker spacer?

Oh, I looked at your other post. Engine suff. I know what you're talking about now. I can't help you though. Sorry.

Yep. It will make sure the rockers don't move.

supposedly helps keeping the geometry in line at higer RPMs ...

for a street motor, i wouldn't worry about it.
Andy

I use them on every engine for several reasons.

1- Added lift or duration can easily overwork the stock springs that are between the rockers, if this happens there is nothing to keep the rocker from sliding off the valve stem and contacting the retainer. If the retainer is contacted chances are pretty good that the keepers will pop off and you'll lose a valve into the chamber- this can be catastrophic failure.

2-The other reason is valve train noise, solid spacers will keep valve trains quieter (at least mine do) because they take the clatter out of the arrangement due to fitting tighter.

3- They boost oil delivery to the valve guides and adjusters because they provide a means of resistance between the rockers that boosts the pressure inside the rockers forcing the oil up to the adjuster end, keeping valves springs and guides better lubricated.

There are many other reasons, these are just a few of my favorites. Very much worth the 16 bucks we charge for them.

I think the VW hydros started the change to the solid spacers. Makes sense I guess, since with a solid lifter, the valve train is unloaded two-thirds of the time, and the spring has that time to reposition the rocker against the pedestal. With hydros, there is some loading all the time, and possibly the rocker can "walk" off the valve tip.

The VW-hydro version has a thrust washer against the rocker, followed by a spring washer, followed by the spacer, another spring washer, another thrust washer and then the other rocker. This is the type I used in my hydro conversion. I polished one surface of the thrust washers and also the inboard edges of the rockers for the same reason Jake describes- to max out the oil pressure in the rocker and hopefully enhance delivery to the valve end of the rocker.

I believe that there are aftermarket versions that are simply a close fitting tube- no spring washers or thrust washers. Seems much simpler and I can't think of any downside vs. the VW setup.

Just some personal opinions.....
Jim