(Excuse me if this is a duplicate, my e-mail was malfunctioning and I am resending).
I've been away from the list for a long time. Just getting the Spit back on the road and ran into a problem not encountered before. I was refitting the head after valve renewal, using new studs purchased from a reputable supplier. 3 head nuts would not come to torque, one of the studs broke w/ot reaching torque. And it appears one of the other 2 studs (at least) started to strip in the head. I checked the torque with two different wrenches, both of which I use regularly, so I'm pretty certain it was not over-torque. This is a combination of events that has left me confused. Some questions have arisen from this novel experience (I've done this operation many times for this and other engines with no problems ever.). 1. From my present confused state of mind, I'm wondering which end of the stud goes in the block, long or short threads. Been doing it the same way forever, but . . . 2. I have been told that the proper head nuts are a grade 5, assuming the studs are a grade 8. This is contrary to fastener industry doctrine which - as I read it - says that a nut should be at least as strong as the bolt/stud. i.e. a grade five could be fit to a grade five or lower. Because the studs are reported to be grade 8, I purchased grade 8 nuts for the next attempt. My plan is to proceed with reassembly again. I have checked the block threads as well I can visually and by running a tap gently in each hole with light lubrication and have blown the debris from the holes. The threads appear ok. Any insight would be appreciated. _______________________________________________ [email protected] Donate: http://www.team.net/donate.html Suggested annual donation $11.47 Archive: http://www.team.net/archive Forums: http://www.team.net/forums Unsubscribe/Manage: http://autox.team.net/mailman/options/spitfires/[email protected]
