Dodgy parts

[duTch]

 

The steel caps are called 'lash caps'

 That's the term I had in mind (didn't)...

 That looks like a handy piece of kit Klaus... ..but also

Like the part. Not crazy about modifying the rockers.

...Also gives extra tappets in the cups and balls...

[RichardL]

...Also gives extra tappets in the cups and balls...

Is that something to look forward to?

Richard L.

[Rocket Racer]

or that given BSA used almost every thread form known to mankind is the rethreading of parts to metric forms  a natural progression or heresy? 

I'd err towards burn the heretic 

Just as well we're a diverse bunch 

[duTch]

 

I'd err towards burn the heretic 

.....hhmmm

 I kinda like the idea of roller rockers...but that's not why I'm here; No work today, so figured I'd check the clearances- in@0.009 /ex0.012 might close the ex to 11...but that's also not why I'm here...

  While doing this check I remembered that the way to do the clearances on my '69 Daytona was to close the adjuster in to zero clearance, and then wind it out something like a quarter turn, to give whatever it should be maybe ~7-8 thou ...sounded a fairly dodgy at the time, but have since figured that depending on the thread pitch (maybe 1/4bsf on that?), seems logical, so I've applied that logic to the A10 and wasted time over a cold tongue lube , and created a tool which I'll paste later........but that's also not why I'm here....

       I had a thought, and another look at Morris's photo, and going by the shape of the indents it kinda looks like maybe the rocker geometry could be a bit wrong, maybe the pushrods are too short/long, (could be a consequence of gasket thickness?) and also maybe the thackery/shims are a bit flaccid...
  I asked about rocker geometry awhile ago, but can't remember any outcome..??
 

[Rocket Racer]

       I had a thought, and another look at Morris's photo, and going by the shape of the indents it kinda looks like maybe the rocker geometry could be a bit wrong, maybe the pushrods are too short/long, (could be a consequence of gasket thickness?) and also maybe the thackery/shims are a bit flaccid...
  I asked about rocker geometry awhile ago, but can't remember any outcome..??
 

A mate sketched these notes up for me for checking my a75, which is slightly different but are very sensitive to rocker geometry for valve wear (typically stems and guides) , but the intention was that at half lift the tappet should be in line (at 90 deg) with the valve stem. Not sure how to best articulate this.
With the A10's and A7's having various cam lift and some with after market pushrods or skimmed heads or differing gaskets its quite likely mainly are not quite optimal

[duTch]

 I'll look at the pics later, but;

at half lift the tappet should be in line (at 90 deg) with the valve stem. Not sure how to best articulate this.

  It's the same principle as brake/clutch cable geometry...??

With the A10's and A7's having various cam lift and some with after market pushrods or skimmed heads or differing gaskets its quite

likely mainly are not quite optima

l

Yep I'm inclined to degree to agree-  (sorry-just had a play on words there).....but also I think you mean

likely many are not quite optima

..?
    It kind've makes sense that if there's a bit more lift involved, geometry will change some- depending maybe on the base radius

[morris]

A little update. I think the adjusters where to pointy and to hard as well. Tried to give one of them a couple of file strokes but that didn't even make a scratch on the surface. Don't understand why they have to be that hard. After all, they're a lot easier to replace than a valve.
I have ordered a set of adjusters at another supplier (bottom of the picture). They have a much flatter surface and are softer to.
The valve train seems to be a lot less noisy now. Gonna run it for a while like that and see what it does.

hi guys, Morris is it possible to get steel caps for them? cheers

Yep. B31 valve caps fit. I ordered a set but decided not to install them for the moment

[edboy]

hi morris, do you mean b31 lash caps fit the a10 valve. if thats a yes i may use them with mushroom adjusters myself on my next project.

[morris]

hi morris, do you mean b31 lash caps fit the a10 valve. if thats a yes i may use them with mushroom adjusters myself on my next project.

Yes, tried them on and they fit. B31 stems have exactly the same diameter as A10's

[muskrat]

The problem with fitting lash caps to valves not designed for them is the added length to the stem and the geometry to the rocker.
Cheers

[edboy]

yes muskrat your right but there might be space to grind down the valve stem, use slightly shorter pushrods or even worn cam followers would compensate.no harm in experimenting if you like fiddling.