Joined: Nov 2023 Posts: 131 Threads: 13
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Location: New Zealand
Car type: 1936 A7 Special
10-05-2025, 10:38 PM
(This post was last modified: 10-05-2025, 10:56 PM by falcott.)
Hi all,
I'm wondering if it's possible to restore the 1/4" threads in the crankcase back from the 5/16" threads that it is currently? I'm thinking of fitting an ally sump, and it will be a shame to drill it out to 5/16.
Or would it be better to change the crankcase?
Ta.
Cheers, Geoffrey
Joined: Aug 2017 Posts: 1,725 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
No they don't, if the case is already out to 5/16 or above I use bespoke brass or aluminium inserts to plug the holes if the case
Black Art Enthusiast
Joined: Nov 2023 Posts: 131 Threads: 13
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Location: New Zealand
Car type: 1936 A7 Special
Ah, okay. I'll look at getting some plugs made up, I guess. It could be an engine-out job.
Cheers, Geoffrey
Joined: Nov 2017 Posts: 167 Threads: 3
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How about converting to stepped studs, 5/16" down to 1/4"? That would save an engine out job.
Joined: Aug 2017 Posts: 1,725 Threads: 47
Reputation:
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
Studs will work although they can make sump removal in-situ difficult. I would not recommend undertaking any of this work without removing the engine first.
Black Art Enthusiast
