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Old 08-31-2011, 10:50 AM
  #12  
opjose
 
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Default RE: You Can Do Engine Problems

Yes we do disagree....

As I've said so often, fuel tank height is only an issue with siphoning.

Typical difference in height when inverting an engine is less than 1/2" on a U-Can-Do, which has absolutely no meaning in terms of pressure differentials.

Fuel weight is not an issue either given the small offset.

I can and have demonstrated this to disbelievers by putting engines on test stands and moving the tank height around.

Not till the tank height difference is QUITE substantial ( typically well over 10+ inches or more ) are there any effects on the engine.

Or engines would not be capable of running upside down, or stay flying on uplines otherwise when the effective differential is often close to those levels.

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As far as upside down starting in a beginners forum.

Many of the "more experienced" set have recommended this here in the beginners forum to newbies who report inability to start an inverted engine.

It may not be the best solution, but for a grossly out of tune engine that cannot be started inverted, it permits the user to get the plane running and start tuning the engine. Once started they can flip it upright.

Ideally the plane should be on some sort of safety support but that's another matter.

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The solution to problems running inverted engines is not "tank height" issues, it's to fix the OTHER setup or starting errors.