Joined: Aug 2017 Posts: 1,705 Threads: 47
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Location: Auckland NZ
Car type: 36 Nippy, 31 RM, 38 Special, 24 Works Rep
Drill the thread out 5/6", tap the cam shaft bush and install a stud with a Dowty washer under the nut, problem solved and it wont leak!
Black Art Enthusiast
Joined: Aug 2017 Posts: 1,637 Threads: 93
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Location: Monmouthshire
As well as emailing and contributing to the forum, Sevenists are very good at talking. Not just in the paddock at Shelsley, Loton Park or certain Lawns, but on the old fashioned telephone. So many thanks to those who have spoken to me, and whose advise was unanimous; don't worry about it. The bolt's purpose is location, rather than structural or mechanical. The square head will stop it coming loose, keep it secure with loctite and oil tight with a copper or Dowty washer. Not quite sure if the machine will be running again by the weekend, but there seem to be two dozen Sevens entered to ascend a hill so much to look forward to.
Joined: Nov 2017 Posts: 562 Threads: 56
Reputation:
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Location: West Yorkshire
Car type: Type 65 1934 + RP 1932
I would not reuse the square headed bolt (the thread of which looks past its best) but make up a replacement from a new hex or cap head. Fairly easy to nip up if needed, or you could drill it and wire it. This would mean that if it starts leaking oil and you decide to follow Ian's advice, at least you can get the camshaft out without having to lift the block again.
Joined: Sep 2018 Posts: 78 Threads: 19
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My original bolt was wobbly and allowed the bushing to move forward along with the camshaft. Destroyed the fiber gear on the dynamo. I redrilled the hole both in the block and in the bushing. Tapped both and installed an Allen head bolt. Worked for me.
Joined: Aug 2017 Posts: 981 Threads: 6
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Location: Scottish Borders
I agree with the use of hex head and I also tap the bush to 5/16 BSF too. This holds it much more firmly.
I've never seen a fibre gear on an Austin 7??
Jim
Joined: Mar 2015 Posts: 5,436 Threads: 231
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Location: Scotchland
04-08-2021, 02:29 PM
(This post was last modified: 04-08-2021, 04:15 PM by Ruairidh Dunford.)
I throw the square headed bolt away, tap 5/16 bsf through the crankcase and into the bush, then fit a bolt with a Dowty washer.
Joined: Mar 2015 Posts: 5,436 Threads: 231
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Location: Scotchland
The only fibre gear I am aware of is inside a magneto, sometimes...
Joined: Aug 2017 Posts: 1,230 Threads: 33
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Location: Salop
Car type: '28 GE Cup. '28 AD Chummy '30 RL Saloon. '34 RP Saloon. Too Many toys!
I've made a 5/16 BSF Cap head bolt into a direct replacement for the square headed abomination. Made it in the pillar drill with a file. No lathe at home. I also removed the square headed abomination without taking the block off.
Had I have taken the block off, Ian and Ruairidhs suggestion is best way by far. Saw it done on a Special I had, very good idea. Just make sure the bolt doesn't bottom out on the cam and nip it tight (don't ask how I know about that one LOL).
Joined: Aug 2017 Posts: 736 Threads: 13
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If your peg bolt is loose or worn it will allow the camshaft to move fore and aft and get a bit too close to the big ends if very bad.
I use a new peg bolt to locate the bush and have a bolt threaded into the side of the bush from the left hand side of the crankcase. I have had no problems from this area for the last 20 years or so. Lockite and Dowty washer stop 60 Psi oil escaping.
