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Re: REFLECTOR: standby vacuum system


> 1) Doesn't bleeding air into the intake manifold downstream of the
> carburetor screw up the mixture to at least some of the cylinders? lean them
> out unevenly?

Don't believe so, but I'll leave it to others to provide the definitive

> 2) If it really doesn't, then why can't a bleed air (manifold suction/
> pressure differential) system be used all the time, with the normal suction 
> regulator placed handily in line?

When the engine is producing full power there is no suction pressure
available. You must throttle back considerably to achieve sufficient suction
to run your instruments. 

> If the Precise flight system gives inadequate vacuum to drive the instruments
> when the engine is... wide open... isn't that a failure of your
> standby system as well?  

It's not a failure, it's a "feature." You will need to run at reduced power in
order for this standby system to work. 

> If this isn't a problem, why can't it be a primary system? 

Suction varies as the inverse of throttle setting. 

For standby vacuum, you could also consider a venturi. These gizmos have no
moving parts and produce suction as long as you have sufficient airspeed. If
you make it retractable, it will not create any drag until you use it. 

Dave Black
SW RG TopDoor