stunthanger.com
Engine basics => Engine set up tips => Topic started by: Steve Thompson on December 29, 2016, 06:53:59 PM
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For the benefit of myself and others, does anyone have a picture, sketch, or drawing of the different types of venturis we use in stunt.
I tried searching and think there are only a few basic types but multiple names for the same thing. Here are the ones I have found:
Restrictor
Regular
Spray Bar
Are these like the stock OS with NVA (needle valve assy) going across the diameter of the venture?
Sprinkler
True
ST Type
Are these like the stock ST with the NVA behind the venturi and several small fuel outlet holes around the venturi ID (also like a cox Tee Dee venturi)?
Flush Inlet
Spigot
Dribble Hole
Fuel Post
Are these like the stock ST but with only one fuel outlet hole in ID?
If there are other types or other names, please add them. The subject name "venturi types" should make this easy to search for in the future.
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For the benefit of myself and others, does anyone have a picture, sketch, or drawing of the different types of venturis we use in stunt.
I tried searching and think there are only a few basic types but multiple names for the same thing. Here are the ones I have found:
Restrictor straight bore through with a chamfer or bellmouth at the top
Regular
Spray Bar Guessing this means the spraybar goes through the center of the intake bore.
Are these like the stock OS with NVA (needle valve assy) going across the diameter of the venture? If you get a wiggly red line under a word, it's MS telling you it's misspelled, and it changes the spelling to what it wants. If you right click and then click on "add to dictionary", it will put "venturi" in your personal dictionary and stop that nonsense. Venturi it is!
Sprinkler
True
ST Type
Are these like the stock ST with the NVA behind the venturi and several small fuel outlet holes around the venturi ID (also like a cox Tee Dee venturi)?
Flush Inlet I think this would be the same as "Dribble Hole", see below. Never heard the term. I have used a "dribble hole", which is the same "venturi" but with the "spigot" or "fuel post" removed.
Spigot AKA "Fuel Post", see below.
Dribble Hole
Fuel Post
Are these like the stock ST but with only one fuel outlet hole in ID?
If there are other types or other names, please add them. The subject name "venturi types" should make this easy to search for in the future.
I don't worry about it a lot. They either work fine or they don't work at all, IMO. y1 Steve
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For the benefit of myself and others, does anyone have a picture, sketch, or drawing of the different types of venturis we use in stunt.
I tried searching and think there are only a few basic types but multiple names for the same thing. Here are the ones I have found:
Restrictor
Regular
Spray Bar
Are these like the stock OS with NVA (needle valve assy) going across the diameter of the venture? Yes, it can be, or a spraybar can be off to the side feeding a circumferential sprinkler galley.
Sprinkler Also called a true venturi since there's no spraybar interfearing with the air flow. It has a collar with usually 3 sprinkler holes feeding into the perimeter of the base of the venturi. A Cox Tee Dee is this type, and is why they don't draw fuel well without pressure(one hole becomes dominant and the others tend to cavitate). On some engines, the spraybar, being off to the side, often acts as a key holding the venturi(air stack) in place.
True
ST Type
Are these like the stock ST with the NVA behind the venturi and several small fuel outlet holes around the venturi ID (also like a cox Tee Dee venturi)? Not necessarily. You'll find Super Tigre spraybars in either sprinkler or through hole venturis. I have a Thunder Tiger Pro 25 with an ST spraybar feeding a sprinkler venturi
Flush Inlet
Spigot
Dribble Hole
Fuel Post
Are these like the stock ST but with only one fuel outlet hole in ID?
If there are other types or other names, please add them. The subject name "venturi types" should make this easy to search for in the future.
Unless you talk about RC Carbs, that's all I can add.
Rusty