Shame... I was hoping to meet quite a few of this forums member. No worries, there'll be other events!
26 NovWith the night run fast approaching, we didn't want to be down to two engines, given that our ongoing issue with No 2 prop puts us down one from the full four. Not groovy! Not happening either. We were determined to repair the snag with No 3 engine.
(this was the issue of a large amount of fuel from the drains, and a reluctance to stop when the Slow Running Cut Off was activated.)
Well, all this week e-mails had been flying backward and forward, scans of manuals, and the Griffon AP was being studied in several homes up and down the country. We had a plan.
Arriving at Coventry early in the morning, we set about removing various cowling panels and then set about removing the intake ducting that contains the filters.
This is secured by pip pins, and a couble of latches, but is made difficult to remove by the drains and the air operated, spring loaded flap that selects where the inlet air comes from.
It took us just under an hour to get the engine to a state where we coud see up into the throttle, and if cracked open, beyond it into the supercharger's intake. The throttle is a rotary barrel, which is in the rectangular duct at the bottom of this pic.
With the aid of a bright light, we than activated the slow running cutoff and the booster pumps. By monitoring where the excess fuel appeared from (as the drains all terminate here) we could tell where the fault lay.
Within seconds there was a large amount offuel issuing from the discharge nozzle - which is supposed to be closed under slow running cutoff, and a small dribble from the solenoids own drain. We did replace both these items last week, but it seems they still werent quite right.
Reaching up into the intake, we could see the nozzle wasn't seating properly, so this time it was removed along with its housing. The AP was consulted, and the parts from the latest mod state of engine fitted - taking care at each stage during reassembly to make sure it was seating.
The solenoid was also removed, the valve body submerged in WD40, and the electrical portion cleaned of decades old grease.
Putting it all back together we once again tested the system, and this time the boost pump was running for double the time required to prime the lines, without any fuel dumping. After getting all the ducting back in place (which it never wants to do) we set about testing the engine.
We had a succesful run, and WR963's No 3 engine now behaves in the expected and proper manner!
In other news..
Work continues on VP293, the ex Strathallen MR1. I'll get some progress pictures shortly, as it should be going back inside over winter. This was very weird to watch as when the tractor first started to move it, I was looking up from working on No 3 and it looked like it was taxying out...
WR963 will be carrying a genuine Shackleton cargo pannier in the bomb bay some time soon, which we are fitting to carry her canopy/wheel/engine covers. This means a little maintenance on the bomb bay carrier points which is no bad thing.
Kind Regards,
Rich
, but hey, it gives us something to look forward to next year
, just a pity that there is a lack of funds/donations etc to get things done quicker
