From: Barry Lovelock
Date: 9/02/00
Time: 6:25:42
Remote Name: 194.168.123.141
The only ever quoted factory figure was in January 1939 and that was 360 inch pounds for 5/16" cylinder head studs! If this really equates to 30lb/ft, then it is far too high I believe. I tried this on one of mine and it really streched the new studs to their limit. In my view, 20lb/ft is more than enough. In actual fact, I always assemble the whole car using almost exclusively Austin spanners. They are much maligned, but have the virtue of opening out when the torque is exceeded! This can almost always be cured by hammering them back again, around a nut. In critical areas, such as axle half-shaft nuts, I use 100lb/ft and a torque wrench, but only here. As a slight aside, there is no set torque for any thread/size combination. Torque is decided experimentally, with a large sample and taking many considerations into account. This includes thread lubrication etc. The test involves breaking the threads, then setting tightening torque as a fairly high percentage, circa 70-90% of the breaking torque - not exactly what we want to do with head studs!!