James
It is a casting fault but not found until pressure or steam applied, I do not recall seeing the hole or would have questioned it when I first saw the cylinder block. It is a 21 core casting so a very complex piece of work and it could be a that a core moved slightly in the casting process. That or the wall between the live steam channel up the centre of the block and the exhaust steam passage has not cast completely around the area where they are closest. Either way the result is a small hole that was probably blocked with casting sand or the thinest web of iron so hiding it until it was to late.
At the bottom of this post is the view of my block after I stripped everyting off it, look up the exhaust passage.
STW have the next batch of cylinder blocks on the machine now so it is just a case of waiting for them to be machined as there were none left in stock.
For the Chetwode Arms event I will onlt be available on the Sunday as I have a previous commitment on the Saturday with my engine at a private event for the club that is testing my boiler. We can alway catch up on the phone sometime.
Cheers
Brian
|