self align rockers or not?

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May 30, 2003 | 11:33 PM

#21

92corvette

Burning Brakes

Joined: Nov 2000

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From: DFW TX

Re: self align rockers or not? (Black87c4)

Quote:

I'm far from a valve expert but doesn't the spring and push rod determine where the rocker sits? Even with the stock stamped rockers on they don't sit on the bottom of the stud, they float above it. I already screwed one of the longer studs in the rockers "looks" the same as the ones with the guide plate still there, I can now screw the lock on because I now have enough thread showing. See what I'm getting at? correct, wrong :confused: as I said i'm not an expert on valves. Anyone?

I think you are on the right track...... :iagree:

[Modified by 92corvette, 10:34 PM 5/30/2003]

May 31, 2003 | 12:04 AM

#22

Black87c4

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From: Taxahoma

Re: self align rockers or not? (Dominic Sorresso)

Quote:

If you are thinking that the rocker is "suspended" on the stud held up by the valve stem and pushrod, you are very much mistaken. The rocker seats on the stud as the base of the stud flares out. That's also why its important to make certain the fulcrum of the rocker is correctly aligned to the stud. I think you may be ok because it sounds like the studs you bought have an extra thick hex section making up for the lack of guide plates.

Don't know why I'm having such a brain fart with this, it's been a long week :crazy: I actually looked at one of my valves that was partly down and it was not hitting the stud base, it might not have closed all the way. How you explained it is how I origionally thought it was but talked myself out of it with all the confusion and wrong parts. I didn't know anything about self vs non self aligned so I did learn something today. I put the old stud with guide plate into a piece of styrofoam and placed the rocker on it, same thing with the new longer stud, the new stud is bigger at the base and has a taper, long story short the valves are the same height so the new stud made up for it and gave me more threads at the top which I really needed. So thanks guys, thanks Dominic :thumbs: Now alot of work tomorrow morning before it turns 95 outside again.

May 31, 2003 | 04:44 AM

#23

CentralCoaster

Team Owner

Joined: May 2002

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From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed

Re: self align rockers or not? (Black87c4)

Sheesh! I think I'm more confused now than I started out. So, have we decided that the rocker does or does not rest on the stud base?

It seems like it'd help hold the pivot snug. I do realize however, that the rocker pivot is actually supported from above, from the polylock. Valve spring pushes up, push rod pushes up, polylock pushes down in between. :yawn:

May 31, 2003 | 09:20 AM

#24

Black87c4

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From: Taxahoma

Re: self align rockers or not? (CentralCoaster)

I know what your saying :lol: valve completely closed it does not rest on the bottom of the stud, I've verified that with the stock ones back on. At fully open it is on the bottom of the stud. That's what I got anyways :crazy:

May 31, 2003 | 10:22 AM

#25

Dominic Sorresso

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From: Bartlett IL

Re: self align rockers or not? (Black87c4)

Quote:

... I put the old stud with guide plate into a piece of styrofoam and placed the rocker on it, same thing with the new longer stud, the new stud is bigger at the base and has a taper, long story short the valves are the same height so the new stud made up for it and gave me more threads at the top which I really needed. So thanks guys, thanks Dominic :thumbs: Now alot of work tomorrow morning before it turns 95 outside again.

That's what I thought would happen. So the rocker is located at the same height with either stud. The fulcrum or pivoting point of the rocker is always in very tight fit with the base of the stud. That's what supports the rocker and keeps it in proper position. The base of the rocker itself must always be moving freely, so no contact with anything. The stud tapers up and the fulcrum has (usually) two different surfaces. One is machined flat and that is the one the polylock snugs up against. The other side is left rounded and the stud taper fits nicely into that. So the fulcrum is anchored in place with polylock at the top and taper at the bottom. If you have reversed the position of the fulcrum, usually the polylocks won't have enough stud to "bite on" or they will sit too high on the stud. :seeya :chevy

[Modified by Dominic Sorresso, 9:28 AM 5/31/2003]

[Modified by Dominic Sorresso, 12:52 PM 5/31/2003]

May 31, 2003 | 01:39 PM

#26

65Z01

Team Owner

Joined: Dec 2000

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From: SE NY

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Re: self align rockers or not? (CentralCoaster)

That's right, the rocker has to float up/down on the stud else we could not set zero lash and then the preload as these operations require the rocker to ride up/down on the stud.

The only possible issue is whether there are enough threads atop the stud for the poly-lock to get a good grip. The poly-lock is the only piece of that assembly that's "locked" in place on the stud.

May 31, 2003 | 02:59 PM

#27

ROME

Racer

Joined: Jan 2002

Posts: 473

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From: Shreveport LA

Re: self align rockers or not? (Black87c4)

Let me suggest hardened push rods if you aren't using them already. I just replaced my CC roller rockers recently. I found that lateral pressures had caused the roller to wear into the body of the rocker. You could move the roller side to side on its shaft and there was a perfect cylindrical slot worn about 3mm into the rocker body. Competition Cams said that, even with guide plates, such wear might occur if hardened push rods weren't used.

I'm using them now, so we'll see what it looks like after another 20K miles or so.

[Modified by ROME, 2:55 PM 6/1/2003]