Stupid question about valve play

[Tapio]

Tried to adjust valve lash last weekend. Took valve covers off. But there’s a strange thingy there in between the rocker and the valve stem top!
What does it do? And why is it sitting there?


https://www.facebook.com/photo.php?fbid ... t=1&ref=nf

To me, when looking at it, it seemed as if it was shaped like in pic 2. So where do you put the feeler gauge?
Or, maybe I’m wrong, and the feeler gauge goes in between the sleeve and the valve stem top?
I was stumped, and stupid enough not to try, so I just put evererything back as it was.

//T

[Corvus]

This is just a guess. It looks similar to what one might find on the end of a G clamp screw. Wonder if it does a similar job? Straighten out an angular motion? I wonder if the tappet screw end has a ball and this piece is "crimped" over the end?

Just guessing though. Dying to know!

Edit: nothing to do with the above, but looks like there are no nested springs? Just single.

[oyster]

Feeler gauge blade slides under the captive cup, above the top of the valve.
This Youtube clip, one of many on the topic, is accurate AND has a good jazz background theme. http://www.youtube.com/watch?v=B8jxG1CH8tc

[Corvus]

Feeler gauge blade slides under the captive cup, above the top of the valve.
This Youtube clip, one of many on the topic, is accurate AND has a good jazz background theme. http://www.youtube.com/watch?v=B8jxG1CH8tc

Captive cup is good. I like that. That's what I meant!

[Corvus]

Anyway, if tapio is using a DTI, clearance is clearance Clarence. Wherever it is.

Use the feelers as a double check. Hopefully the two methods will yield the same answer.

[R-man]

As others have suggested this sort of fitting is designed to reduce the sideways pressure on the end of what is a long and potentially bendy valve stem. And I think it helps to slowly revolve the valves in their guides, for more even wear.

Tapio - Although I was taught that using a test dial indicator was the more accurate way, when you have 4 of them to do, and find that resetting any one can influence the others it may be slow, and over the top...

[ceepee]

hi Tapio, i have exactly the same issue as you re checking clearance i.e. nowhere apparent to insert feelers, one thing that does come to mind though , is the valve gear show in the picture of a boxer cup rep or is it common to all 1100s engines, i refer to the double domed fitting between the valve stem and the rocker adjuster ?

[Corvus]

?..........and find that resetting any one can influence the others........

That's a point. If each pair of valves shares a rocker, which it looks to do, once you set one valve clearance using the DTI, it won't be possible to set the shared valve clearance using the DTI.

DOH!

Looks like feeler gauges only. If the valve stem indents the captive cup face...... You're stuffed I guess.

?

[Herb]

Deleted.

[R-man]

-ceepee- Yes all R1100 and 1150 engines are like this, with 'captive cups' (were they invented by Berlei?). This series is known as type R259, and much of the valve gear is interchangeable until the 1200 series that replaced them.

The more I think about it, the more I like the feeler guage setup.

Cheaper than 4 x DTIs
Much quicker, especially if you keep all 4 feelers in at the same time (oo-err missus)
And can easier measure any variation as the rocker arm moves vertically on its shaft (unless the rocker arm end float is truly tiny).

-but I still have a hankering to try one of those 'SPQR' pre-settable valve clearance adjusters, that was a mechanic's friend when all cars had simple screw-adjusted OHV or OHC rockers...

[Droptarotter]

The technical term for the captive cups is;

Elephant Feet

Cheers

[Herb]

Deleted my previous post. Must remember not to post while under the influence. Especially on technical posts.

I can't see the method using a dial indicator being accurate. As the rocker arm can be assumed to be quite rigid, surely regardless of where you position the dial gauge, you are only going to measure the tighter of the 2 clearances on that arm?

[Corvus]

Deleted my previous post. Must remember not to post while under the influence. Especially on technical posts.

I can't see the method using a dial indicator being accurate. As the rocker arm can be assumed to be quite rigid, surely regardless of where you position the dial gauge, you are only going to measure the tighter of the 2 clearances on that arm?

That's what I meant in my last post. I hadn't cottoned on to that fact initially, but R-man's comment prompted my noggin.

Judging by his last post though, I'm not sure he actually meant that! Why would you need four sets of feelers? Two would probably be helpful, but surely just one would suffice? Perhaps I'm still missing something?

Herb, it's awfully unsporting of you to delete your cock ups old chap.

[Corvus]

The technical term for the captive cups is;

Elephant Feet

Cheers

.....and in German please......

[Corvus]

I have thought of a way of setting the clearances using a DTI. Please feel free to shoot me down in flames.

Feelers are fine, but how are you going to know if the elephant feet are becoming indented by the hammering against the valve stem? The dia of the elephant foot looks bigger the the valve stem.

Using the DTI. Back off each screw. Use the DTI to set one of the screw clearances. Then push the rocker to make firm contact between the screw you've just set and the valve stem. Then, keeping firm pressure on the rocker, finger tighten the second screw to zero clearance.

The only flaw I can see with that idea is that when tightening the locknut on the second screw, you may slightly change the settings.

How flawed is the idea?