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Re: Problem lapping head to barrel on a '54 VH500
Posted: Fri Feb 18, 2022 4:44 pm
by 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.
Re: Problem lapping head to barrel on a '54 VH500
Posted: Fri Feb 18, 2022 7:20 pm
by dennis.t
Julian,
Thanks for the tip. I will check the fit with engineer's blue. And thanks for the torque value.
Dennis
Re: Problem lapping head to barrel on a '54 VH500
Posted: Fri Feb 18, 2022 10:58 pm
by nevhunter
That's not a torque figure. It's a pressure. Do you mean 20 ft/lbs?
Re: Problem lapping head to barrel on a '54 VH500
Posted: Sat Feb 19, 2022 8:32 am
by Julian Murphy
Yes. Slip of the pen...
Been testing too many valves.
Should read ft/lbs
Re: Problem lapping head to barrel on a '54 VH500
Posted: Sat Feb 19, 2022 10:51 am
by keith.mettam
Hi Dennis,
A 1958 Ariel factory document gives 25 ft lbs torque for the head bolts.
All the best,
Keith.
Re: Problem lapping head to barrel on a '54 VH500
Posted: Sat Feb 19, 2022 1:30 pm
by dennis.t
Keith, thank you for the clarification.
Dennis
Re: Problem lapping head to barrel on a '54 VH500
Posted: Fri Mar 04, 2022 7:47 pm
by 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.
Re: Problem lapping head to barrel on a '54 VH500
Posted: Sat Mar 05, 2022 8:06 pm
by dennis.t
Will do thanks,
Dennis