This is after being installed and preload set. Basically the total possible motion of the pushrods in the guideplates and the trunnion between the snap rings. Normal or too much? Will it actually move this much during operation?

http://home.comcast.net/~jsaccani2/MOV02817.MPG

 

That's normal. Just so the roller stays on the valve tip.

 

[QUOTE=A/G]I should hope so! Jeff, it helps to take into consideration the impact of the RA ratio. If you have just .015" clearance at the PR, you've got over .02" at the valve. However, you've got more that .020-.025" side play. To me, it looks excessive. How many miles on those RAs? Didn't you have a RA bearing side play question awhile back?[/QUOT

I haven't seen anything in the past 40 years but shaft rockers NOT have slack.

Ya might want to look into having those micrometer eyeballs re calibrated as it's very hard to tell from a picture what the slack IS.

 

There's about 700 miles on the rockers (before the spun bearing).

There's definitely more side play than the amount due to the PR play being amplified at the valve stem due to the rocker ratio. There's also side play due to the trunnion sliding back and forth until either side contacts the retaining clips.

(My previous question was regarding whether to take the total motion into account when centering the roller tip on the valve.)

I suppose I could contact Comp Cams to ask how much trunnion play there should be, but past experience has told me that it's difficult to get a straight, much less accurate answer from them sometimes!

Edit: Took a quick measurement, there's about 0.010" total clearance between PR & guideplate slot, and about 0.019" total play at the trunnion. So that should be about (0.010)*1.6 + 0.019" = 0.035" total motion at the stem. Sure looks like more than that though!

 

Sure does Jeff, though I question your computations. Side clearance itself does not determine total rotational movement of RA itself.

Anyway, I can tell you why it is not as great as it really is. It's because you have eyeballs (micrometer or otherwise) that may need calibrating. Are your eyeballs QS9000? Enuf foolishness!

Your pic is very clear, allowing a fair determination of the amount of movement. Though I previously stated I believe it to be excessive with an ATTEMPT to determine the cause, to some, apparently that implies I must KNOW the cause already. I also did not state these RAs should have NO clearance that would allow for movement, did I?

I grabbed a rebuilt (CC) roller rocker to make a simple 'eyeball' check of the side clearance. To me it looked to be ~.010". As my eyeballs may not be calibrated, I made a simple setup to check with an indicator. Yup, my eyeballs were off! The actual side clearance was .009". With the setup, I checked several rebuilt as well as used (same mfr.) RAs with many thousands of street miles.

Of the several rebuilt RAs I checked, turned out the .009" was an average of the .007-.011" that I found. I followed through and determined the rotational movement to be .018" for the sample with the .009" side play. I picked one of the more worn used RAs to do the same checks. It had .016" side clearance with rotational movement of .034". Mind you I believe these to be potential rebuilding candidates. It obviously depends on builder's tolerance range. HTH.

In case there is any confusion, I should clarify the 'rotational' movement will take into account both the side clearance of bearing along with any clearance within the bearing itself. IOW, total physical RA (at the valve) movement possible. The inspection checks made were with the RA itself achored at the trunnion. The RAs were not mocked up on heads. Though there is no accounting for PR clearance in GP, it will not add to the rotational movement of .034" at the valve end. Subtracting .016" side play from the total .034" comes to .018" actual rotating slop or clearance at the valve. This equates to .012" at the PR end. Regardless, the free movement of the PR tip will not force the RA beyond the physical limits allowable within itself.


Ref:

 

I called Comp Cams and they said there should be between 0.015" - 0.020" clearance between the rocker body and the clips. I'm getting about 0.019".

And I see what you mean about my calcs. I was thinking that since the rocker body is translating on the trunnion that it wouldn't create any rotation at the valve tip, just translation. I missed that the whole body would rotate about the PR tip due to the translation. That means I'm probably getting more like 0.050" motion at the tip.

 

I'm convinced some of their hired help is paid minimum wage. People usually get what they pay for. Call back later and see what the next guy states. I see no reason for setting them up that loose. As I noted, rebuilds I've received were in the .010" range, which I consider more than enuf for performance or for durability reasons. I checked one that had ~.002". Although it was addressed to be similar to the rest, I wasn't convinced it be an issue.

That means I'm probably getting more like 0.050" motion at the tip.

I consider that a good minimum guessimate. It may be closer to .060". No way to know what they were new, but unless there is something really HS in your setup, not much if any wear should have occurred in 700 mi. It looks as if you just have one hell of a loose set of rockers. Your engine!