Topic: Question for sandcast guys about "special" screws for cam holders

[markb]

I'm ready to put my cam holders on and my parts manual says there is a special 6 x 56 screw (item #4 in the diagram).  All my notes and pictures show a standard hex "8" screw (but it had been apart before).  Also when I checked through my fasteners (from almost 4 sandcasts) I found no screws that matched the parts book.  I'm wondering if the special screw was ever used.  My question is has anyone seen the special cross, hex, flange screw called out in the early parts book?

[Bodi]

I believe the only "special" attribute is the 56mm length, this is not a standard bolt length. Later engines did use standard length (60mm) bolts, so I suspect there's a good reason not to use those on a sandy.

[markb]

The length may be special.  But, hard to see in the copy of the parts manual, the screw shown has a hex head with a flange and cross (phillips-type) head.  That definitely makes it special.  I tried ordering that part number (90043-300-000) and they were superseded to a standard hex head, 92000-06056 which is a 56mm screw.  Unless someone says they've seen them I've concluded that since they're not available and that I couldn't find any in four sandcasts that they we probably never actually used.

[754]

The partsbook should show which serial number used them, if I remember will check mine.
 Did any of yours have the waffle pattern inside the valvecover?

[markb]

My April, 1969 parts book says the special, 90043-300-000, is from CB750E-1000001 and to no number.  My CB750-K2 parts book shows the “special” in the diagram but calls out the standard “8” hex head, 92000-06056 (56mm), from CB750E-1000001 to CB750E-1064902 (well into the K1’s) and switches to a 92000-06060 (60mm) after that.  This is another indication that the “special” was never used.  I only needed to know because of my anal desire to make my sandcast restoration as correct as I can.

E100 has the waffle valve cover.  I have a better pic somewhere but here is what it looked like when I took it off the engine before it was cleaned up.