Problem lapping head to barrel on a '54 VH500

[Julian Murphy]

As long as you have a gap between the head and the barrel. I had 0.016".

You could blue the spigot, place head on square, and lift off square, just to check the fit to the head,

As somebody else mentioned, very carefully clean the head as the grit in the paste will get embedded in the softer alloy.
(Grinding paste designed for hard valves and hard seats really, where its unlikely to become embedded)

Head bolts torqued to 20 lb/sq in.

[dennis.t]

Julian,
Thanks for the tip. I will check the fit with engineer's blue. And thanks for the torque value.
Dennis

[nevhunter]

That's not a torque figure. It's a pressure. Do you mean 20 ft/lbs?

[Julian Murphy]

Yes. Slip of the pen...

Been testing too many valves.

Should read ft/lbs

[keith.mettam]

Hi Dennis,
A 1958 Ariel factory document gives 25 ft lbs torque for the head bolts.
All the best,
Keith.

[dennis.t]

Keith, thank you for the clarification.
Dennis

[RogB]

The head sits on the spigot not the barrel. This provides a high contact pressure to provide a gas tight seal. But check with engineers blue that there is full contact between head recess and spigot. Then use fine paste if necessary.

[dennis.t]

Will do thanks,
Dennis