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Costa P Costa P is offline
Slippery slope skier
 
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Join Date: Sep 2010
Location: South Africa
Posts: 179
Garage
December Progress

The progress made over the last few weeks summarised in photos:

1) Rocker Arms
  • The arms were re-bushed and reamed to size.
  • I have purchased new rocker shafts since the old ones were quite badly worn.
  • Lastly, I hand lapped the rocker pads to freshen up the surface and remove all wear marks from their previous stint.

BEFORE:


AFTER:


Results after 2000grit (dry)



Before everyone bombards me with their concerns:
  • What about the profile?
  • What about the surface hardness?
  • What if the surface isn’t true with the cam?

For those of you that don't know me, I suffer from OCD (Spenny, you are not alone mate).

a) I did the lapping myself, paying particular attention to how I held the rocker in my hands, while lapping the pad over a single sheet of water paper, against a flat granite surface (AKA kitchen counter…..my wife is still upset with me). The trick is to apply light pressure while making slow, complete strokes from heel to toe of the rocker pad (Rawknees….BEHAVE!) Careful to not favour lapping a small area, but always the whole pad. Careful to keep the pad true against the granite.
I spent approximately 30-40min per rocker. Starting with 800grit (dry), proceeding to 1200grit(dry), 2000grit (dry) and finally 2000grit (wet).

It is a slow process which requires lots of patience. With the 800grit, you gradually remove material until the old wear marks are completely gone (Note: The rocker pads were in good shape to start with). The 1200 and then 2000 gives you the required surface smoothness. The 2000 (wet) gets rid of the visible marks and leaves the mirror-like finish.

b)Very little material was removed (ie. compared to grinding by stone). I am confident that the original surface treatment/hardness is more than deep enough.

c) The final proof that all was ok, was achieved be spraying marking blue on all the rockers and turning it over a couple of time to inspect the contact. All rocker pads and lobes made correct contact across their full width.
Old 12-07-2016, 09:23 AM
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