The Dowty type seals work very well in place of the original copper ones (which I never use) and I just use the stock ones available VOCSC under the pipe fittings....as Tim said make sure the lower sealing surface is nice and flat......pipes that have been chromed often are not from the wire tying process, leaving a ridge in the chrome...dress off flat with a broad flat file. The tapered unions can also give similar leaks so good idea to check that they are in fact nipping up tight...I have found on occasion even when you feel the fitting is tight, that the other part is still loose, and well able to leak. I actually use a tiny bit of Loctite 518 on all the surfaces before final assembly. The 1/4 BSF modified bolts of the ET 100/1 Mod are quite capable of pulling the threads out of the anchor nuts housed in the rocker bush assembly.....This has not happened to me but others have had this experience, but in general, practice the following......if you use a small length spanner of the correct fitting size, and nip up firmly with good hand pressure till nice and tight, this should be well enough. If you use spanners/sockets with handles very long, you will easily over torque the item and damage will result, usually splitting the seal under the pipe fitting. You will find they need to be "Nipped" up a couple of times over a few engine runs/heat cycles.......but I generally do this the same time as I re-torque the cylinder hold down nuts, and reset the tappets.......All good fun, cheers.........Greg.
