CBG Workshop
IT’S ALL A BIT OF A MESS, REALLY. MARIA and Butch stripped the early 6T Thunderbird engine of its head and barrels, finding valve guides that had seized onto the valve stems making them loose in the head, and partial the pistons and barrels. Good points were that the big and little ends felt nice and the oil drained showed no nasty metal shards in there.
Triumph twins are arguably the most popular of British motors and so there’s no shortage of opinions when you have a problem – from experts or amateurs! In the end we decided to go with standard size (not oversize) valve guides, not cast iron ones like original, but of ‘Colsibro’, a copper/nickel/silicon alloy, from Norman Hyde.
They are also longer to help dissipate heat, and the inlets come machined to take stem seals to reduce oil let into the combustion area.
Maria had bought a spare cylinder head at an autojumble, so we cleaned all the valves up and have used the best
