Furlough Day II

On my last Furlough day, I took the opportunity to go for a week-day ride.  The weather, on that occasion, was at the “turning point”.  Up until then, we had been enjoying spectacular crisp clear winter days – the sort that makes this time of year the best time to ride in.  The day after my day off, it rained…  And rained…  And rained…  In fact, Brisbane had the most rain in a 24-hour period since 1974.  The day after, it rained almost as much, again!  As such the weather was “rolling-in” on my ride and I was lucky to only traverse a small amount of wet roads and even less rainy weather.
For this Furlough day, I decided I would work on the RGV. The weather was not going to intrude on me this time!  (It was a good job I had planned an indoor activity as it did end up raining all day)  Everyday life interfered a bit with progress on the bike and as such I only really got to spend around three hours tinkering with the bike, on the day.
I took the opportunity to replace the various Philips head screws that I removed with Allen key-headed bolts.  It seems to be a fairly standard technique when restoring these bikes and will hopefully assist in easier removal next time I am servicing the parts.   The nuts on the cylinder head bolts were also badly worn – so I replaced these with new stainless steel ones.  It had been mentioned on the forums that the two dissimilar metals would lead to galvanic corrosion.  I am no metallurgical expert, but it was also mentioned that copper washers could be used to avoid this problem.  So I bought and used some of them as well!  I highly recommend going to a specialist fasteners shop when you need to buy nuts and bolts.  They tend to sell higher quality parts, you can get the exact numbers of what you need and they do not come with the ludicrous price mark-up that the generic hardware shops have for “packs of ten”.  (As an added bonus, you will talk to someone who knows what they are on about and can probably offer you some advice!)
The RGV engines have “powervalves”.  The purpose of the powervalve is to restrict the flow of gases exiting the combustion chamber at low engine speeds.  At higher revs, they “open” allowing more gas to escape.  A detailed description of what they do and why is probably worthy of its own blog entry, but the reason I mention them is that they are notoriously weak on the RGV.  If the powervalve breaks, it can drop into the cylinder barrel, where it tends to be collected by a piston travelling at upwards of 12000 RPM.  The results can be quite catastrophic.
Whilst I had the engine apart, I took the opportunity to inspect the powervalves (there are four of them) and discovered one looked suspiciously like it was on the path to failure.  So I was able to replace the faulty part and clean them up.  Powervalve inspection is possible to do with the engine in place, but seeing as though I had it removed, it made the task far less onerous.
The cylinder barrels themselves appeared to be in good shape – there was no plating missing or damaged, so I installed the new pistons and rings and put the engine back together.
The next task is to reinstall the engine in the frame, check / set the powervalve adjustments and  refit the cooling and exhaust systems. Then, I’ll feel like I am getting somewhere with the project!

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