344. Down and Dirty

Our maintenance week started with a fairly simple list of jobs, and this week at Shuttleworth to get them done.

  1. Repair damage to the rear fuselage fabric.
  2. Repair the slackening of the tailskid in its pivot bracket.
  3. Colour code the struts by painting narrow strips of contrasting colours on the tops of the struts, the sockets in the upper wings, and the box they live in in the trailer to ensure they don’t get muddled.
  4. Reposition the pulsometer to try and make it work at all times.
  5. Seal the minor leaks in the petrol tank
  6. Do a routine check on the engine by pulling all the cylinders
  7. Remount the tacho cable gearbox more securely.
  8. Repair the damaged wheel trim.
  9. Complete the wiring of the solar panel charger to the trailer winch battery.
  10. Dope a fabric bandage onto the freshly-made dummy propeller, ready to have holes shot in it.
  11. Clean the flies off the back of the propeller.

Monday started fine – I’d driven across to Biggleswade, the wings were off and the fuselage in the nice warm engineering hangar by lunchtime – and with Theo and Chill arriving late morning, we had the engine out by the close of play.

Theo and Chill getting up close and personal with the engine…
… and shortly afterwards, out she came.

So far, so good.

Tuesday started in a great mood, therefore, and when Ninja David took the first few cylinders off, everything looked immaculate.

Spotless piston…
… and spotless cylinder.

And while he was on with that, we managed to extract the petrol tank.

The tank came free finally.
You can see some evidence of leakage here – probably from about half a dozen rivet heads, which is what we were expecting.
The condition of the tank elsewhere was generally reasonable.
The brass oil tank looks immaculate, thank goodness. The petrol tank is bad enough to remove, but this would be a nightmare!

However, as David worked his way round the engine, he came across some broken piston rings.

Here’s one in situ…
… and we’ve ended up with five or six that need replacing.

There are one or two areas of external rust on the tank that are causing some concern, and we’ve taken the decision to have Shuttleworth etch and paint the tank with two-pack epoxy, which Andy assures us is the only paint system that is impervious to castor oil!

Otherwise, we are making good progress with the rest of the jobs.

But the two issues above cannot be resolved this week, so we’ll have done as much as we can by tomorrow night and go home early, and fix another date to reassemble.

The broken rings are a considerable disappointment and a relief; we aren’t yet sure why they broke, but at least the pistons and liners are in good condition.

Investigation into the cause is continuing; we need to be sure we’ve cracked the problem (and not the rings) before we run the engine again.


One thought on “344. Down and Dirty

  1. John 'Simba' Evans

    Fine work, pity about the piston rings but the bore looks good. All the best from Bristol.

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