virgin - timesert cam stud

[henrywillms]

Got your attention you lecherous buggers....I am a first time timeserter. I am about to timesert my RGS 8mm cam studs, one is stripped (center exhaust). I have read some previous posts but still not quite sure of one thing. The originals threads are countersunk in the head and the top thread is about 5mm down. The outside diameter of the top lip/shoulder of the timessert is a slightly larger than the inside diameter of the bore in the head above the threads. Do I use the countersink tool to countersink all the way down to the top of the threads (new threads that will be cut)? This seems to make sense so the stud length above the head remains the same. Or do I just get the countersink just below the surface of the head so the timesert is flush with the head, and if so can I use the studs as is or do I need to shorten? Could I grind the shoulder down a bit, still leaving a bit of a shoulder, and not bother with the countersink tool...sounds crude I know. In theory this would let the remaining shoulder stop at the top thread without having to countersink.     

Related question. One of the original threads (which is not stripped) starts lower than the others, and it is too low for the first part of the countersink tool to center on. Do I need to get a bushing made to allow the countersink tool to center in the larger diameter bore above the threads or....?  Thanks.   

 

[sfcpiet]

By all means install the Timesert as it is intended to be.  Any alteration to the insert will weaken it.  Also be sure to use one of the correct length,ie, it needs to be able to be spread with the spreading tool which must pass through the insert.  If the insert is too long and too close to the bottom of the hole, this will not be the case and the stud may not be able to be screwed in fully without jamming... the next stud removal will have the insert firmly jammed to the stud!  Applying a drop of Loctite to the insert (on the outside thread of course!) upon installation doesn't hurt either.

The Timesert countersink tool doesn't allow the insert to be sunk in deep enough for the stock studs.  The insert will end up slightly below the head surface.  Either modify the tool to allow it go in deeper or shorten the stud accordingly, no big deal with RGS-style cam bearings.  Early dowel-located bearings do need the counterbore for the dowels, the only option here is to modify the tool.

HTH,
piet

 

[henrywillms]

Piet, thanks. I will counter bore as far as the tool allows. The tool is Wolfgang's so I can't modify it!!!! If studs then sit too high and interfere with the valve  cover I will cut/grind them down a bit.  Wolfgang supplied a couple of different lengths of timeserts and it looks like even the long ones will leave enough room for the tool to pass through and fully expand the timesert. For the one stud where the bottom of the shank of counter bore tool does not reach the smaller diameter threaded portion so I can't center it, I will either make a bushing for the tool or find another way to create the counter bore using a drill or dremel. Appreciate the experience, it provides me confidence to proceed.