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Cal-look/High Performance => Pure racing => Topic started by: kingsburgphil on June 15, 2012, 23:27:10 pm



Title: broken adjusting screw
Post by: kingsburgphil on June 15, 2012, 23:27:10 pm
Just snapped the cup end off a Berg rocker adjusting screw. This happened at 7K on a motor with two hrs. run time on it.

Common or freak occurrence ?  ???


Title: Re: broken adjusting screw
Post by: TexasTom on June 16, 2012, 00:28:33 am
How far is it threaded into the rocker arm?
If it's extended to far out on the bottom of the rocker the geometry will create excess stress and snap them!
I, personally, have yet to break one.
TxT


Title: Re: broken adjusting screw
Post by: kingsburgphil on June 16, 2012, 03:01:05 am
How far is it threaded into the rocker arm?
If it's extended to far out on the bottom of the rocker the geometry will create excess stress and snap them!
I, personally, have yet to break one.
TxT

couple of turns, say 3 mm from bottoming out, maybe .010 side clearance. A little sloppy, but not gross.
I replaced it from one I robbed from my extra set of Bugpack rockers.


Title: Re: broken adjusting screw
Post by: TexasTom on June 16, 2012, 23:46:53 pm
Phil,
Was it the hollow type (for oil flow) or solid? Just curious ...
TxT


Title: Re: broken adjusting screw
Post by: Fiatdude on June 17, 2012, 00:04:25 am
Sorry to hear about that Phil -- Personally I have always felt Robbed everytime I bought something at GB ---- Could always find something as good for 1/3 the price somewhere else ----

My Pauters have taken a ton of abuse and still never failed ( this was caused by my screw up)

(http://i586.photobucket.com/albums/ss306/Fiatdude/photobucket-10176-1339888062628.jpg)


Title: Re: broken adjusting screw
Post by: kingsburgphil on June 17, 2012, 02:13:02 am
These are the solid ones, and I don't know if thats good or bad. The more I think about it, it's probably just metal fatigue. Every time this old fool gets
into the "way back machine" he puts the boot to it. Granted the rev limiter is set at 7,200, down from 8,400 back in 03'. But running a FK89 with K800's
has got to be hard on the little bits. 



PS. I think its time to get a new camera  :D


Title: Re: broken adjusting screw
Post by: OC1967vw on July 20, 2012, 19:46:04 pm
These are the solid ones, and I don't know if thats good or bad. The more I think about it, it's probably just metal fatigue. Every time this old fool gets
into the "way back machine" he puts the boot to it. Granted the rev limiter is set at 7,200, down from 8,400 back in 03'. But running a FK89 with K800's
has got to be hard on the little bits.  



PS. I think its time to get a new camera  :D





KP,
It sounds like you have the Berg swivel feet adjusters (gb 341-aka "elephant feet adjusters") which are solid. We used those way back when. However, the Berg ratio rockers use the hollow style (with the oiling hole-GB 343) and not the elephant feet adjuster that Gene pioneered way back in 1969.

You didnt say whether these were brand new or used. I am presuming that they are used? Texas Tom is correct on the cup style adjusters and the amount of thread that protrudes out the jam nut. If using other than VW rockers they require shims under the stands. Your pushrods might be a source of the problem as it may be too long causing the swivel foot not to "swivel". Insufficient shimming does not give you the proper clearancing for the swivel foot to "swivel" as well. Hope it all works for you on your motor.


Title: Re: broken adjusting screw
Post by: dangerous on July 20, 2012, 23:30:11 pm
Berg Rockers are a bush type arm,
and the adjuster must have an oil hole because it needs to have oil flow to the bush.
This means a solid adjuster will starve the bush for oil,
so have a close look to see if the bushings show any signs of  the problem.

The other issue is you may have too much adjuster hanging out of the arm.
This is an important issue when the adjuster is only 5/16" in diameter.

Normally I would set the adjuster never more than one turn from the under side of the arm.

Unfortunately this may be a comprimise on the berg arms,
because not only does the geometry become the important issue,
but also the adjuster must be positioned within the arm to maintain oil flow to the bush.

If you must hang the adjuster out , at least make sure all the threads are within the arm.

Quite possibly the reason it has broken
is because the arm has begun to seize on the shaft due to lack of lubrication,
but as mentioned above, the adjuster cup should not be out so far.


Title: Re: broken adjusting screw
Post by: OC1967vw on July 21, 2012, 01:00:39 am
Just snapped the cup end off a Berg rocker adjusting screw. This happened at 7K on a motor with two hrs. run time on it.

Common or freak occurrence ?  ???


In re-reading the thread,KP, you didnt state what rocker arm you are using. Standard VW, Berg ratio rocker, or other manufacturer?


Title: Re: broken adjusting screw
Post by: kingsburgphil on July 21, 2012, 02:20:11 am
 >:(