Does anyone know where I can get -

[alan_thomas]

Fitted in each cylinder head located behind the rear water transfer cover there is a threaded plug that blocks the end of the oilway. The plug is, in turn, drilled and threaded to take one of the 5/16 bolts that hold the rear cover on.
Need one of these plugs but cannot see them on any of the usual suppliers parts lists.
anyone know where I can get one?
- Alan

[Gaeda]

Is this plug meant? Google: UKC3163

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[alan_thomas]

Thanks , how did I miss that!

Is this plug meant? Google: UKC3163

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[DJT]

Thanks , how did I miss that!

The question is "how did you lose the one you had?"

[alan_thomas]

The question is "how did you lose the one you had?"

Instead of the 5/16 bolt holding the cover winding out of the plug it unscrewed the plug out of the head. Don’t know why it was so tight but efforts to separate the bolt from the plug resulted in damage to the outside thread of the plug.

[dasadrew]

The question is "how did you lose the one you had?"

.... and the next question is how come they are readily available off the shelf as a spare part .....

[Goldstar]

.... and the next question is how come they are readily available off the shelf as a spare part .....

Slow moving part so maybe an old "stash" - it fits TR7 heads as well. Maybe the TR7 line had a load left over. It is an odd part to be so available though, I agree

[Philip Wardle]

Looking at the parts book, each water transfer housing has five hex head setscrews in with 5/16 inch UNC treads - one HU857 in each corner (7/8 inch long) and one HU856 in the middle (3/4 inch long), so the internal tread of UKC3163 will also be 5/16 inch UNC.

This thread form is confirmed by inspection of my spare heads. Mine have one threaded insert each in mirror image positions. Both inserts are recessed below the surface, one at 30 - 40 thou depth depending on where measured, and one at 50 -60 thou.

When trying a setscrew in the inserts both bottom out at 1/2 inch depth relative to the surface. The holes without inserts bottom out at 17/32 to 9/16 inch, i.e. 1/2 inch plus tolerance. I haven't removed either insert to check the outside thread form, but I think it's 7/16 inch UNC.

So, overall, my guess is that a suitable generic insert, if we need one, could be an E-Z Lok 313-5, which is 5/16 inch UNC internal, 7/16 inch UNC external, length 17/32 inch. But I haven't verified ...

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[KOY 23]

Although not my question, what a comprehensively well researched reply. Respect for all your contributions Philip.

[Philip Wardle]

Thanks for your kind comments ... I don't know whether the original parts were E-Z Loks or just looked like them, but they have an adhesive coating on the outside threads which activates when they are installed. This would account for difficulty in removal, but apparently the adhesive can be released by heating the inside of the insert to 300 F. I might have to think carefully about how I would do this if it ever come to it !