Author Topic: B31 cylinder head bolt threads  (Read 1312 times)

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frogeye

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B31 cylinder head bolt threads
« on: 26 May, 2018, 14:01:08 »
Hi there,
Located a used b31 head. Seller says the cylinder head bolt threads are weak/loose. Is it possible to restore these threads?

AWJDThumper

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Re: B31 cylinder head bolt threads
« Reply #1 on: 26 May, 2018, 17:20:48 »
In principle, you can insert Helicoils into cast iron but you would probably need to get it done at a machine shop - it might be best to contact one before buying the head.

frogeye

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Re: B31 cylinder head bolt threads
« Reply #2 on: 26 May, 2018, 17:55:49 »
Yea, was thinking about that but where on earth could one get a british thread Helicoils?

ducati2242

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Re: B31 cylinder head bolt threads
« Reply #3 on: 26 May, 2018, 18:05:18 »
Yea, was thinking about that but where on earth could one get a british thread Helicoils?

Amazon do imperial helicoil kits
1956 bsa GS DB500
1968 mk1 Rocket 3
2006 ducati 999R .

AWJDThumper

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Re: B31 cylinder head bolt threads
« Reply #4 on: 26 May, 2018, 20:26:03 »
Yea, was thinking about that but where on earth could one get a british thread Helicoils?
They are readily available but I'm not sure whether the drill and tap that comes with modern kits are up to coping with cast iron - that's why specialist advice would be worth seeking.

paulm

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Re: B31 cylinder head bolt threads
« Reply #5 on: 26 May, 2018, 23:15:31 »
The kit supplied by recoil is very good i have used it no problem

frogeye

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Re: B31 cylinder head bolt threads
« Reply #6 on: 29 May, 2018, 02:35:06 »
Thank you!

wells01

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Re: B31 cylinder head bolt threads
« Reply #7 on: 02 July, 2018, 16:49:03 »
Hi
I have exactly the same problem with my 1952 B31.
I would like to try a Helicoil type repair but cannot find the thread size of the head bolts.
Any ideas.
Many thanks.
David Wells