Tappet Cover oil leaks

[Charles P]

Hi Charles,

Im using a similar early block and have made a valve chest cover exactly as your first post suggests. An O ring grove round three sides of the back face and one running across the top. As mentioned in previous posts there'll be little leakage from the top unless there is insufficient breathing. Belts and braces you could countersink the plate exactly where the studs come through (add a few thou clamp load) and make some matched thumb nuts so when you tighten them down it pushes the plate up against the top O ring, I decided against this on grounds that life is too short. I'll take some pics and post them up if it would be of interest. 

Tom

Thanks Tom (et al). Very useful content. 
I suspect that the 10mm plate is rigid enough to ensure even clamping pressure. I had a moment of wild imagination and considered getting a chum with a CNC mill to cut the Austin logo into it - and then I thought better of such a frivolous idea! I am going to seal the screws with Dowty washers to help stop the small possibility of leaks from there.
And I'll replace the 5/16 pipe used for the catchtank with a 3/4" one.

Charles