The photo shows the rearmost block to crankcase stud hole, which has been tapped 7/16 BSF and which had a stepped 5/16 stud.
How to proceed? Acquire another 7/16 - 5/16 stepped stud, which don't seem readily available off the shelf, or plug and tap to 5/16? The 7/16 thread appears good to me. There's not much meat left in the crankcase so I'm not keen on removing any more material.
I think either is a technically acceptable solution Colin, but a new stepped stud will probably have to be purpose-made and will cost you, unless you are able to do it yourself. For my money I'd plug it and start again. Secure the plug with Loctite and make sure it doesn't stand proud of the joint face.
Joined: Aug 2017 Posts: 1,230 Threads: 33
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7 Location: Salop
Car type: '28 GE Cup. '28 AD Chummy '30 RL Saloon. '34 RP Saloon. Too Many toys!
Not wanting to teach anyone to suck eggs, but you can make stepped studs in a pillar drill provided you have the patience a file, a caliper (or mic), a vice, some button dies and a haxsaw. Start with a quality 7/16 BSF bolt.
The trick is to get the step as flush to the crankcase as possible. it usually means glueing it in
06-03-2019, 03:58 PM (This post was last modified: 06-03-2019, 04:01 PM by Steve Jones.)
I made a length of 7/16" BSF External - 5/16" BSF internal insert for a job yesterday, Colin. I've about 3/4" left that should solve your problem. You're welcome to it. Give me a call if it will help.
