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Quick rocker geometry question
Keith Haeusler - September 4th, 2009 at 08:58 PM

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 - September 5th, 2009 at 05:54 AM

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)


Keith Haeusler - September 5th, 2009 at 06:18 AM

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 - September 5th, 2009 at 09:42 AM

hey Keith, cant believe u just posted this topic, i was doing the exact same thing last night and had a very similar problem:crazy:...... 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.


vw54 - September 6th, 2009 at 09:09 AM

more or less shims under the mounting stud ???


grogy - September 6th, 2009 at 05:40 PM

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 - September 6th, 2009 at 06:03 PM

Quote:
Originally posted by vw54
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.


RodPenrose - September 6th, 2009 at 06:40 PM

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.