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Quick rocker geometry question

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Keith Haeusler Seriously Crusin Dubber

168 posts · joined Sep 2002 ·

#733479
Hi all,

Just setting up the rockers this week and seem to have some funky issue happening. When i set the pad on the rocker ( berg 1.45 ) to give me a nice narrow contact area in the centre of the lash cap, i cannot get the pushrod to be parallel with the adjuster at 1/2 lift.

If i set pushrod to 1/2 lift parallel, then the rocker pad wants to wipe off the edge of the lash cap.

The heads are CB ultra wedge with +200" valves. Maybe the longer valves are causing me grief? or maybe i am just missing something here.

Anyway, whats better to aim for. I would assume the contact area on the valve tip is more important.

Regards, Keith

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 ·

#733501
Yeah its the longer valve dude.
Hard to see without a pic WHICH SIDE OF THE LASH CAP it is riding on,
but with .200 longer the valve gets closer to the rocker shaft.

So 'worst case', you may have to move the rocker stud,
or give Pat Downs a ring, he may know which rocker arm suits.
Theirs are the same shaft size as bergs, so you may be able to go that way,
or a different shaft and block from another ratio arm set.

On the Autocraft heads we used a pauter arm and autocraft rocker shaft,
or 1.5 arms with1.4 shafts to move it over. (just to give you an example of what might need to be done)
westi wrote:That's mad Alan.

Keith Haeusler Seriously Crusin Dubber

168 posts · joined Sep 2002 ·

#733502
Thanks Dave,

Appreciate that. I will call up and ask Pat he`s recommendation. It actually wants to ride on the `top` side of the lash cap.

Will let you know what he suggest`s.

Regards, Keith

polak Everything is alright with enough Vodka :P

913 posts · joined May 2009 ·

#733522
hey Keith, cant believe u just posted this topic, i was doing the exact same thing last night and had a very similar problem🤪...... at 1/2 lift my adjusting screw wasnt perfectly straight inline with the pushrod, mike and i figured it was to do with longer valves in the CB oval port heads..... we opted to go a small shim under the rocker gear as it was only out very little and the benefit of this was that i also was able to utilize the chromoly pushrods iv already got.


VW - helping put oil back into the ground for over 60 years

grogy Custom Title Time!

1,000 posts · joined Aug 2007 ·

#733735
im doin same thing, i got one rocker riding about half on the valve but nearly totally on the lash cap......is it ok ?, otherwise the rocker neads to be machined[pauter 1.5s]

polak Everything is alright with enough Vodka :P

913 posts · joined May 2009 ·

#733738
vw54 wrote:more or less shims under the mounting stud ???
more, i dont like using shims for anything, but in this case i needed to anyway.... only one 30 thou shim on each mounting stud, gave plenty of clearance and straightened out the rockers very nicely.


VW - helping put oil back into the ground for over 60 years

RodPenrose Insano Dub Head

792 posts · joined Apr 2005 ·

#733750
Keith , I have had the same problem with the longer valves in some heads . What you need is a shorter in length rocker from the mounting boss to the rocker pad . As the valves are longer , the top of the valves are closer to the centre of the head . I have tried every different brand and ratio available to find that the Pauter aluminium roller tip rockers work well . I have set up a 250 thou longer valve in a set of std vw cast heads and the Pauter rockers were the only one's that fit . If you need a set to make sure this is what you need let me know and I will send a set up to check before you order them , ROD.
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