Technical JTD head bolt size

[pycoed]

Son's 98 105 JTD ( Bravo actually, but seeing as I'm here...) has a busted cambelt & we've just found we don't have a Torx bit the right size to loosen the head bolts. Can anyone tell me the exact size, is it Torx or Ribe & where to get one?

 

[hagar]

on my petrol 1.8 they are a size 12 ribe bolt for the head

 

[pycoed]

Its actually a Ribe 14 but things are looking tough (see other post)