Cylinder Head Tie Rods

[David S]

The cylinder heads are pulled down to the crankcases with tie rods (four per cylinder). The cylinder heads have threaded inserts cast into them to receive the tie rods. I need to know what that thread is. As far as I can tell its 3/8" 16tpi Whitworth but it could be 3/8" 16tpi UNC. (Or it could be none of those!!) Does anyone out there know for sure?
DWS

[David S]

I think I've answered my own question. It's an M10x1.5mm left hand threads and not Whit or UNC.
DWS

[Rob B]

Correct DWS!

I had sixteen new sets made up by a local Engineer in Stainless Steel Type 303 which is excellent material in tension, and rustless. The sleeve nuts are 18mm hex head - 20 x 1.5 x 31 overall