B31 cylinder head bolt threads

[frogeye]

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]

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]

Yea, was thinking about that but where on earth could one get a british thread Helicoils?

[ducati2242]

Yea, was thinking about that but where on earth could one get a british thread Helicoils?

Amazon do imperial helicoil kits

[AWJDThumper]

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]

The kit supplied by recoil is very good i have used it no problem

[frogeye]

Thank you!

[wells01]

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