Rocket end float adjustment

Slipperyeel

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Over the weekend I finally got around to checking/adjusting the end float and valves then a throttle body balance. I bumped into one puzzle. The LH rockers were spot on. RH rockers seemed to need some adjustment. But I'll be damned if I could move it. They weren't miles out but I ended up not being able to get it any further than this...

ATTACH]


I left it at that, but has anyone else bumped into this? Or did I miss something? The bolts holding the rocker support were loosened and I tried tapping/moving the support, but it would only move on the rearward side. I'm not particularly bothered but thought I'd share it.
 
In case anyone is wondering what i'm on about in this post.. Basically i could get two 0.05 gauges into the RH rocker. It was impossible to move the support to close the gap.
The engine is definitely happier after the work (which inc. the cleaning of a very gungy BBS). But in the interest of perfection, it was very frustrating!


And lastly, iv'e only just noticed the typo in the title! Lol. - Administrator, it seems i can't edit the post?
 
Certainly did. Nut was well loose. (though I hate tightening those flippin bolts, that 180° turn always feels counter intuitive!). Good thought though!


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I know I'm going to regret saying this but.... why are you sticking 2 guages in? I only measure the float at one end. The top fixing with the 2 head bolts through is non adjustable anyway, plus the rocker just floats up and down so measuring at one end is all thats required... or so I thought...

And 0.05 at one end is perfect anyway:) Or am I wrong...again:)
 
I know I'm going to regret saying this but.... why are you sticking 2 guages in? I only measure the float at one end. The top fixing with the 2 head bolts through is non adjustable anyway, plus the rocker just floats up and down so measuring at one end is all thats required... or so I thought...

And 0.05 at one end is perfect anyway:) Or am I wrong...again:)


Ah! That was to illustrate the 'problem' i.e. that i was able to get two gauges in. But I was measuring at the bottom. Both gauges were a nice sliding fit so it's still within tolerance, i think? (0.05 + 0.05 = 0.1).

It was not being able to move the support that flumoxed me. I wondered if anyone else had come across this.
 
Checked mine recently and the intakes were both at 0.20 mm and both the exhaust are 0.10 mm, the wear limit is 0.40 mm so I didn't think it was necessary to adjust anything at the moment.
I have a reasonably detailed service history and there's no mention of the end float ever having to be adjusted after 45k miles :thumb2

I can't suggest anything but if everything is as it should (and it sounds it is) then just ride and enjoy :D

Did your wings arrive ok ?

Cheers,

Mike.
 
Mike. Wings arrived. Thank you!

For the end float, I've decided I might take another look when I change the oil in a few weeks. As Mikeyboy says, the tolerances are pretty much spot on (except for that one rocker). I did turn the engine around several revolutions to double check, much as you do for the valves. There was no change to any end float measurements, very consistent. Hence my head scratching.



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I found that the way the rocker shafts locate in the support 'bar' means that it'll only move perpendicular to the shafts and won't 'twist' to accommodate changing one side without the other changing also. This means that if the machining tolerances were slightly out (as in my case), then with the left hand rocker set perfectly, the right was slightly too 'open' but it was impossible to close that gap down without closing up the left hand side too.

I just set the left at the minimum and lived with the right being slightly above minimum (but still within the allowable range).
 
Matt. Thanks for the input. Interesting point, which I think fits. The idea that the support will only move upwards in a parallel fashion rather than rotate a little makes sense to me. I didn't think of that.

I'll be going in for another look in a couple of weeks so I'm going to keep this in mind.

Cheers!


Sent from my SM-N910F using Tapatalk
 
I found that the way the rocker shafts locate in the support 'bar' means that it'll only move perpendicular to the shafts and won't 'twist' to accommodate changing one side without the other changing also. This means that if the machining tolerances were slightly out (as in my case), then with the left hand rocker set perfectly, the right was slightly too 'open' but it was impossible to close that gap down without closing up the left hand side too.

I just set the left at the minimum and lived with the right being slightly above minimum (but still within the allowable range).

Makes total sense. So if I adjusted the LH side to 0.05 min play then the right side would drop to 0.15 I expect?

:thumb
 
Makes total sense. So if I adjusted the LH side to 0.05 min play then the right side would drop to 0.15 I expect?

:thumb

Probably :)
It'll depend on the machining of your head - apparently some will allow some degree of 'twist' whereas some like mine are pretty tight and the support bar will only move both sides together.
 


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