29-07-2018, 10:22 AM
Hi Charles
Many get hold of these or cruder versions without making.
Most of my observations are aimed primarly at the not too experienced, who seem to make up many of newcomers.
It is very tempting to narrow wide seats by opening out bore but that is usually a mistake.
Considering that the average Seven has had a myriad valve grinds, seats are often surprisingly good.
My car used to burn valves of old time steel every 6,000 or so and I have reports of same from others in the 1940s-50s.
(common James brand exh valves were of VK+ steel, inferior even to XB, and now only used for inlets.)
Many get hold of these or cruder versions without making.
Most of my observations are aimed primarly at the not too experienced, who seem to make up many of newcomers.
It is very tempting to narrow wide seats by opening out bore but that is usually a mistake.
Considering that the average Seven has had a myriad valve grinds, seats are often surprisingly good.
My car used to burn valves of old time steel every 6,000 or so and I have reports of same from others in the 1940s-50s.
(common James brand exh valves were of VK+ steel, inferior even to XB, and now only used for inlets.)