Well we really got off on a tangent with this thread and since I helped with that let me see if I can help return it to the original topic.
Here are some pictures of the Clutch Boss that I just re-worked this morning to try and show where all the new holes are located.
As mentioned previously STOCK holes are in ribs numbered 1, 6, 11, 16, 21, and 26. These are also the ribs with oil channels on the inner diameter.I DID NOT enlarge these six holes on this boss. But I DID add one more hole in the ribs numbered 1, 11, and 21 close to the front edge, actually about .150 in. This dimension is to the center of the hole from that front edge.
My rib numbers are counter clock wise as I used that back face that the judder ring sits up against as a reference point and each STOCK hole is located out a little further from that face running CCW, starting with the #1 hole/rib being closest to it.. This face has a little red dot on it above the number four but not real noticeable so In the third picture I put a blue X on that face.
The first picture shows the boss held in a vise with the drill positioned by eye so it will drill through the rib without breaking through on either side of the rib, Each rib is rotated up and checked like this prior to drilling to assure the drill will be centered in rib,.
Picture #2 shows approximate positons of the holes to be added with the red dots. The little red lines on the left side show me which ribs will get a new hole added. I did spend some time looking at the locations in or out on the ribs to try and get the most uniform oil coverage with each new hole.
In picture #3 you can see the red dots as well as where they are located between the stock holes located in ribs #1 & #6. You can also see where a new hole will be added in rib #1 out near the front edge.
In picture #4 you see the finished boss. It now has two more holes added between each of the STOCK holes, as well as one more hole added in the oil channels in THREE places but further out to get more oil under the first four clutch discs. This also shows the numbers for which ribs have had holes added to them.
Hope that helps....and finally, you can mess with trying new/different oil, adding the new clutch washers, changing WR to YZ springs, removing the judder ring and adding another disc,changing out all or some the plates,as well as changing the clutch actuation rod (as I did for three months) OR just adding these 15 holes and one new four dollar fold over tab washer and fixing it the FIRST time into it.Your choice.
Edited by ThumpMe, September 03, 2014 - 09:59 AM.