Mailing List flyrotary@lancaironline.net Message #35527
From: Bill Schertz <wschertz@comcast.net>
Subject: Re: [FlyRotary] Re: Cowling and engine installation RV 7A
Date: Sun, 18 Feb 2007 11:57:03 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Al,
His message says 'bypass line' , and from earlier discussions, some builders put a bypass between high and low pressure with a small orifice to bleed any air that might get in there without having to develop full pressure. I see a flex fuel line going tothe other side of regulator, which would be the high pressure supply, and the line out the bottom looks like it goes back to the tank. The short line just bypasses the regulator, and I assume has a small orifice to allow pressure to bleed down.

Bill B -- Am I correct on this?
Bill Schertz
KIS Cruiser # 4045
----- Original Message ----- From: "al p wick" <alwick@juno.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Sunday, February 18, 2007 11:11 AM
Subject: [FlyRotary] Re: Cowling and engine installation RV 7A


We have a strong tendency to make theoretical decisions. Why not pursue
the facts? There are a number of things you can do. If you could dig up a
strobe like I suggested, then you could actually see the tube bend. This
really improves understanding of what's happening.

Another way to prove your theory is to ask the question "What do the
experts do in this situation?". Fortuntately, in this case we have
thousands of examples you can look at. Just go to local car dealer and
pop the hood of all the rotary Mazda's you can find. Hard plumbing fuel
lines is less expensive. Did they hard plumb, or did they install more
expensive hoses between components? Typically you will find they install
short length of rubber hose to reduce stress concentration of hard line.
You will also find they tie off all hard lines and wires every 6" or so.
This controls the frequency response of the components.

Trying to save a life here Bulent, not trying to convert anyone to the
dark side. It looks like he's sending fuel return line directly back into
the fuel inlet. Very dangerous.


-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam
timing.
Artificial intelligence in cockpit, N9032U 240+ hours from Portland,
Oregon
Glass panel design, Subaru install, Prop construct, Risk assessment info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html


On Sat, 17 Feb 2007 18:37:19 -0500 Bulent Aliev <atlasyts@bellsouth.net>
writes:
Al is forgetting again that we don't run no stinkin pistons :) Our
engines are smooth unlike the old piston engine concept.
Buly
On Feb 17, 2007, at 12:31 PM, al p wick wrote:

> Absolutely NOT ok. So glad you asked the question. You can prove

> this to
> yourself by shining adjustable strobe on the plumbing while the
> engine is
> running. You will find the tubing bends significantly in response
to
> various engine rpm. This will fatigue the tubing. This is called
hard
> line plumbing. It increases your risk significantly. Ironically a

> lot of
> guys will get away with it, some for a few years. It all depends
on
> whether your plumbing length corresponds to natural frequency of
the
> system. If you placed one or two supports on tubing, then that
would
> limit which frequencies it responds to. Greatly reduce risk.
Flexible
> line also dramatically reduces risk. I had a $million warranty
> issue once
> where the engineer did the same thing you did. I use strobe at
the
> science museum I work at to show patrons how things bend. It's so
> educational. I can rub my hand on metal bowl and it causes water
to
> splash out of bowl onto patron's face. Just by controlling the
rubbing
> frequency. I use strobe so they can see the metal deform from
> vibration.
> My bowl has cracks in it now from fatigue.
>
> BTW, just excellent job on wiring. Lot's of wire ties control that

> same
> vibration. Looks attractive.
>
> I'm a little puzzled by your plumbing routing. Why do you send
that
> line
> back to the other one?
>
>
> -al wick
> Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and
cam
> timing.
> Artificial intelligence in cockpit, N9032U 240+ hours from
Portland,
> Oregon
> Glass panel design, Subaru install, Prop construct, Risk assessment

> info:
> http://www.maddyhome.com/canardpages/pages/alwick/index.html
>
> Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and
cam
> timing.
> Artificial intelligence in cockpit, N9032U 240+ hours from
Portland,
> Oregon
> Glass panel design, Subaru install, Prop construct, Risk
assessment
> info:
> http://www.maddyhome.com/canardpages/pages/alwick/index.html
>
> --
> Homepage:  http://www.flyrotary.com/
> Archive and UnSub:
http://mail.lancaironline.net/lists/flyrotary/


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-al wick
Cozy IV powered by Turbo Subaru 3.0R with variable valve lift and cam
timing.
Artificial intelligence in cockpit, N9032U 240+ hours from Portland,
Oregon
Glass panel design, Subaru install, Prop construct, Risk assessment info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html

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Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net/lists/flyrotary/

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