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Re: Second Venturi

Posted: Fri Nov 08, 2013 4:37 pm
by hilltop170
Thanks guys, I could not remember seeing a 4" long or a 8"dia venturi, makes sense now!

Re: Second Venturi

Posted: Sun Nov 10, 2013 6:37 am
by GAHorn
Bruce Fenstermacher wrote:More specifically it is referring to the amount in inches a column of mercury would be raised by the vacuum over the level at atmospheric pressure.
....at 100 mph. :wink:

Re: Second Venturi

Posted: Sun Nov 10, 2013 6:25 pm
by Bruce Fenstermacher
gahorn wrote:
Bruce Fenstermacher wrote:More specifically it is referring to the amount in inches a column of mercury would be raised by the vacuum over the level at atmospheric pressure.
....at 100 mph. :wink:
It is a team effort to remember all the details. :D

Re: Second Venturi

Posted: Mon Nov 11, 2013 3:10 am
by GAHorn
Bruce Fenstermacher wrote:
gahorn wrote:
Bruce Fenstermacher wrote:More specifically it is referring to the amount in inches a column of mercury would be raised by the vacuum over the level at atmospheric pressure.
....at 100 mph. :wink:
It is a team effort to remember all the details. :D
Yep. The group knowledge in this outfit is pretty impressive.

Re: Second Venturi

Posted: Thu Nov 14, 2013 5:32 am
by ptporebski
I replaced my vacuum instruments with modern ones (Sigma-Tech DG & AI). The existing venturi's (old and of uncertain manufacture) would not generate the requisite 5" of Hg. Spoke to Spruce, their related manufacturing arm, and the engineers at Sigma-Tech. They confirmed what this thread says. My vacuum gage (which I had calibrated) showed that I needed a vac regulator. Bought one from Spruce (Rapco) and all is well now. As soon as the engine throttles up I have 5" vacuum through all phases of flight. :D

Re: Second Venturi

Posted: Thu Nov 14, 2013 7:22 am
by spduffee
Alrighty then. That is what I shall do. Thanks for the infos. Once I am able I will upgrade to at least one 8" or 9"-er, add the vacuum regulator and install my Artificial Horizon.