Get the lead out

Day Three, and here's how you check the torque on the prop gearbox. With a carefully measured 6' BFS and a fishscale.

 

Every wonder what's inside the gearbox? Once you see everything apart and learn how it's designed, your ability to operate the engine goes up exponentially.

The engine is designed to run on ethanol free autogas, but for convenience people will run 100LL avgas. Problem is, 100LL is not really "low lead", but has a considerable amount of lead in it. You can add Decalin to help the lead from sticking, but once it's in the engine it remains there. Here's some lead fouling a gearbox

And a turbo that had been run for 2,000 hours on pure 100LL, fouling the wastegate. 

Turbo inlet vane. Spins at 70,000+ rpm, makes engine very very happy on a hot day. 

Stacks and stacks of engines, waiting to be shipped. In 1982 Vernon businessman Ron Shelter talked Rotax into producing aircraft engines and created Rotec Research Canada, in 1988 Rotax went into production full time. There are about 3,600 Rotax 912s sold each year, and about 400 914s.

Doing a compression check. Why is the engine on a truck? 

Here's why. In the afternoon the class adjourned to a taxiway and we ran the engine

 

After we had a chance to run the engine, Mike sent us inside and "broke" it, then we came out to troubleshoot it.

"Are you SURE that's the problem??"

 

With a couple hints, we figured it out. This was the end of the 3 day class, tomorrow we start the 2 day Heavy Maintenance class. Cool.

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