B31 Exhaust valve guide

[mr_tench]

Hi, I need to fit a new exhaust guide to my B31 but I have been unable to find any stock in the UK.
Does anybody know if the outer diameter and length of the inlet guide is the same? If so is it feasible to modify an inlet guide by boring and reaming to suit the larger diameter of the exhaust valve.
I have access to a lathe and could make one but should I use Meehanite or Bronze stock?
Thanks,
Roy

[ducati2242]

I had to make my own valve guides for an ariel square 4 . so lots of them . I made mine from Bronze and haven't had an issue , but , I have very little mileage on it as of yet . If you do make your own the info i managed to find said in an alloy head make them 2 though bigger than original . I did this heated the head and tapped them into place with a purpose made drift . I had to re-ream them when they were fitted so there must have been a bit of a squeeze on them . As for material again I could only find people who suggested Bronze so I'm unsure on the Meehanite you have suggested . If the ones that are in are Bronze I would go like for like . The ones in my B34 are Bronze coloured .

[martinh10]

Have you tried Draganfly? They are showing stock of both 65-1144 (1946-48) and 65-1514 (1949-53).

[paulm]

Head 1.468, Stem Lengh 3.828 Stem diameter .3480

[Pete C]

just miced up inlet and exhaust guides and they appear to have the same external dimensions so I see no problem in opening out an inlet guide to serve.       

I always assumed that cast iron guides were recommended for iron heads. Bronze etc is more suited to alloy heads (so I have been told)
I use GG25 for making guides, after experimenting with GG60 which is only really suitable exposed valves - it wore out fast!

[mr_tench]

Many thanks to those who have replied. I've now placed an order with Draganfly. I did look there but it seems I confused myself! Draganfly actually shews no stock for the inlet guide. I got an inlet from Ray Fisher at Britbits and was only looking for the exhaust guide.
Roy