What torque setting should I use for the head gasket of my 1932 BSA 500cc side valve?

email (option): jonathan.billington@blueyonder.co.uk

There's this in the technical section. http://www.wdbsa.nl/bolt%20torque%20values.htm But not sure it would apply to a 1932? Torque settings were not usually given back then. Best to follow the sequence and tight is tight by feel. Ron

email (option): ronpier@talk21.com

Alloy heads are 20 ftlbs to 25 ftlbs
Iron heads go 30 ftlbs to 40 ftlbs.
Fine threads tend to the lower limit & coarse threads towards the top

Most engine from that era end up needing to have a thread insert fitted or be tapped out to the next size bigger as the threads wear over time

email (option): bsansw1@tpg.com.au

I don't think I'd want to risk a 3/8" BSF head bolt at up to 40 lbs? But I've never tried it? Ron

email (option): ronpier@talk21.com

Err,
"Fine threads tend to the lower limit & coarse threads towards the top"
bottom of a 30 to 40 used to be 30 when I went to school, butt that was a looooooong time ago.

A 3/8 BSF grade 8 or higher will happily go to 40 ft lbs.
However you should have strait BSW in cast iron, that is the metal it was designed for.
BSF should be used on nuts that are running on steel cause it was designed for use on steel.

Or as my metalwork teacher used to drum into us
"The stud connects the Fine Forging to the Coarse Casting."

email (option): bsansw1@tpg.com.au

OK on that. The threads in the cast iron barrel of an M20 are 3/8 BSF and it's these threads I fear will give out before the bolts, hence the need often for inserts. Ron

email (option): ronpier@talk21.com