PV9685

IIRC, to use the self-aligning rockers the valves should be +0.100? I believe that is what I have heard, of course I may be incorrect.

So, I am looking to clear things up. I'm using a set of Vortec heads with new valves and the retainers from my TPI heads. So, I take it that the stock retainer that GM puts on self-aligning heads drops down around 0.100 in order to make more room from the self-aligning grooves?

I am just wondering because it seems like +.100 valves that are 1.94/1.5 are tough to find! (Well, at least inexpensive valves that are only slightly better than stock.)

sofakingdom

iTrader: (1)

You may have heard correctly, and even recalled what you heard correctly; but what you heard, if it was THAT, was incorrect.

Stock valves for SA rockers are the same length they've always been; 4.911" nominal. So no, they don't have to be .100" long.

GM uses the same garbage retainers they've always used, with the worthless and ineffective oil shields and those weird "rotators" they put on there for who knows what they're supposed to do. They didn't change anything at all about any of that when they went to SA rockers. But nobody in his right mind would use any of the stock valve train rubbish when building a performance head, anyway, would they? (would they?) Kind of a moot point how it fits when it's already in the trash where it belongs.

What might have been correct however, but was garbled somewhere between the fact and the recollection of hearing, is that a certain amount of valve stem must be exposed above the keepers; otherwise the "rails" on the tip of the SA rockers will hit the keepers, instead of the tip itself of the rocker landing on the valve stem. Which could get ugly quickly. Some otherwise perfectly acceptable performance valve train setups can get you into that particular Hell fairly easily; for instance, the combo of face-milled valve stems (or even ones that just have the keeper grooves a couple of .001"s higher than usual), +.050" or +.100" keepers, and SA rockers, could easily put you into Pete and re-Pete time.

PV9685

Hmm, great to know - I am glad to hear that. I suppose perhaps my "hearing" was extrapolated from threads where people went with aftermarket valvetrains with SA rockers and ran into contact between the SA rails and the retainers. I suppose it is easily possible that the retainers were thicker or oriented higher, or the grooves in the valve were higher up. Thanks for the help!

BTW, I am a budget-enthusiast! I try to get the most out of certain stock parts and budget performance parts... however by budget I don't mean "ProForm", "ProComp... etc... by budget I mean parts like Manley Budget Street Performance valves, cheapy Hedman full length headers, Carter 70 GPH high PSI fuel pump, Holley 4 barrel, Weiand single plane intake, etc, etc.. the low range of high performance! Or perhaps they are simply low-performance parts

I go for that seat-of-my-pants on Saturday and drive a four-door car on week days. haha! Besides, if you build too much power you just have to buy more parts...