From: FLYCOZY@aol.com
Date: Thu, 21 Oct 1999 23:51:09 EDT
Subject: COZY: Re:Vacume line

Fellow Builders;   
    One of the things that I had a little trouble with when I built my first 
plane was that when I got all done and was hooking things up when I got to 
the vacume pump I had no line to hook up because there was'nt one.  I guess 
Nat  planned on us using electric.  But my engine came with a vac pump an I 
was to cheap to replace it and go to electric.  
   I will say that Nats plans are second to NOBODY.  have you ever seen the 
plans for a KR 2 or the Velocity ?  It makes is so easy the even people who 
should'nt build an airplane can.  
   Lucky for me someone name Rex Pershing said don't  forget to put in a 
vacume line from the firewall to the regulator. What I did on the Mark IV was 
using a 3/4 in hole saw drill a hole throught the firewall through the gear 
bulkheads entering the inside of the fuselage underneath the arm rest on the 
pilot side rear armrest. The hole through the firewall was at a slight angle 
below the control tube for the controls and above the electrical channel.  I 
just floxed in a 3/4 OD tube and attached a long length of clear plastic 
tygon tubing through the front seat bulkhead and under the map pocket to the 
regulator mounted by the pilots left calf with a bracket glassed to the 
fusalage side. The tubing is glassed to the sides of the fusalage about every 
8 in.  
    From the pump to the firewall I had a hard time finding a hose that was 
3/4 ID. and reinforced.  I found one at the marina used for a bilge pump on a 
boat.  I had to get a different fitting on the pump to accommidate to 3/4 
hose but everthing works.  If this info helps anybody It will be worth all 
the running around I did to figure it out The new fitting on the pump was 
expensive $ 35.00
                                                                              
              Good Luck
                                                                              
                Dennis .    

From: cdenk@ix.netcom.com
Date: Fri, 22 Oct 1999 17:52:17 -0400 (EDT)
Subject: Re: COZY: Re:Vacume line

I would be concerned with the plastic hose collapsing from the vacuum. On short lengths it possible to snake a steel coil 
spring like (possibly from 0.42" safety wire) as an internal support. Agreed, the vacuum line doesn't show on the Cosy plans 
either, but should be their. I didn't notice its absence until the tub was complete. Then cut holes through the bulkheads, and 
pulled an 5/8" diameter "0" temper aluminum tube in to place. It wasn't easy, the aluminum workhardened from straightening the 
coil, and more from wiggling it in to place, but it got there. From low on the firewall and instrument panel where an inch of 
tube protrudes, I use 5/8" tygon tubing from there to the pump and regulator.

Date: Sat, 23 Oct 1999 15:57:23 -0500
From: "Daniel D. Pettinger" <DPettinger@ibsw.com>
Subject: Re: COZY: Re:Vacume line

Ed,
I'm in the middle of chapter 6.  Sometime soon I'll want to install a vacuum
line.  Did you run yours inside the heat duct? or what path did you find that
works most effective?

Dan Pettinger Cozy MKIV #722 Chapter 6

"Edmond A. Richards" wrote:

> I had the same experience with the vacuum line that Carl describes.  The
> plans are great but there are a lot of things that you just have to "know"
> or you wind up re-doing.  I have done much discovery and re-doing.  When I
> installed the vacuum line the interior of the aircraft was complete.  In
> the process I managed to cut one of the nylon brake lines, hole sawing
> through the front seat back (it's hard to see while standing on your head).
>  Want to guess when I found the leaky line?  I'm still trying to dry the
> oil out of the carpet.
>
> The moral of the story is to run the vacuum line in the early stages of the
> "tub" construction.  And yes, I think it should be in the plans.  Seems to
> me a whole lot more useful than the Loran ground plane in have installed in
> the fuselage bottom.
>
> Perhaps in addition to the FAQ in the archives we need LESSONS LEARNED from
> those that have gone before.
>
> Ed Richards
>
> Cozy #88

From: cdenk@ix.netcom.com
Date: Sat, 23 Oct 1999 18:45:05 -0400 (EDT)
Subject: Re: COZY: Re:Vacume line

Was asked: Did you run yours inside the heat duct? 
Mine is on the left side, low, mostly within 2" of the floor. But I have a Cosy, which is much like as Cozy 3.

Date: Sun, 24 Oct 1999 19:55:11 -0400
From: "Edmond A. Richards" <EdRichards1@compuserve.com>
Subject: Re: COZY: Re:Vacume line

Dan Pettinger wrote:

>what path did you find that works most effective?<

Dan,

I ran the Vacuum line inside the arm rests on the left side of the fuselage
below the aileron torque tubes, near the floor.  I use 5/8" soft  Aluminum
tubing and floxed it in place through the gear bulkheads and used 
vibration isolation through the firewall.  The regulator is forward of the
instrument panel near the floor.  Worked out pretty well with the pump and
the instruments both on that side of the fuselage.

Ed Richards

Cozy Mark IV #88

Date: Mon, 25 Oct 1999 17:38:17 -0500
From: "Daniel D. Pettinger" <DPettinger@ibsw.com>
Subject: Re: COZY: Re:Vacume line

Ed,
Are there any advantages of using aluminum tubing over plastic vacuum tubing?

I'm new at this. I have never put a vacuum pump on an engine or hooked a vacuum
line to a pump so I'm not certain what or how "vibration isolation through the
firewall" works.  Would you enlighten me?

I'm in the middle of chapter six on the Cozy and am considering running 5/8" ID
plastic tubing for the vacuum line.  What I don't know is, "How much excess
tubing to leave ahead of and behind the instrument panel and firewall?"  Any
suggestions?

Thanks,
Dan

"Edmond A. Richards" wrote:

> Dan Pettinger wrote:
>
> >what path did you find that works most effective?<
>
> Dan,
>
> I ran the Vacuum line inside the arm rests on the left side of the fuselage
> below the aileron torque tubes, near the floor.  I use 5/8" soft  Aluminum
> tubing and floxed it in place through the gear bulkheads and used
> vibration isolation through the firewall.  The regulator is forward of the
> instrument panel near the floor.  Worked out pretty well with the pump and
> the instruments both on that side of the fuselage.
>
> Ed Richards
>
> Cozy Mark IV #88

Date: Thu, 25 Nov 1999 01:05:18 -0500
From: Jim Sower <jimsower@mindspring.com>
Subject: Re: COZY: vacuum source

I bet it'd work great.  I do believe I'll look into it myself here directly.
Why spend the $$ on vacuum pump when lots more interesting stuff can be
mounted on that pad.  Of course if you have engine failure in IMC ... ;-) ..
but the regular pump would go then too.
Don't nobody live forever.  It's a great idea.  Hope it works.   Jim S.

alwick@juno.com wrote:

> Bruce Frank from another newsgroup suggested using the exhaust pipe to
> develop vacuum for my 2 instruments. Accomplished by inserting small diam
> tube at angle into pipe. Reportedly exhaust rushing by tube pulls
> substantial vacuum. Enough to overrev gyro.
> Anyone familiar with this technique? I used similar method to make
> machine gun for my RC plane years ago. Worked well.
> I've got all the goodies to test it. Regulator, check valve, inlet
> filter. Thought I'd test w/o instrument hooked up initially. Whatcha
> think?
>
> -al wick
> Canopy Latch System guy.
> Artificial intelligence in Cockpit
> Cozy sn 389 driven by stock Subaru 2.5 ltr 106% complete, Aug 00 first
> flight sched..
>
> ___________________________________________________________________
> Get the Internet just the way you want it.
> Free software, free e-mail, and free Internet access for a month!
> Try Juno Web: http://dl.www.juno.com/dynoget/tagj.

From: cdenk@ix.netcom.com
Date: Thu, 25 Nov 1999 08:24:46 -0500 (EST)
Subject: Re: COZY: vacuum source

With the exhaust source, what safe guards are there to pressurizing the gyros with corrosive exhaust gases? Could have some 
strange things happening when an engine backfires or false start. Seems that the way nature tends to equalize things, these 
gases, when shut down for a long period of time would make their way to a gyro, with not good effects.

Date: Thu, 25 Nov 1999 09:00:31 -0500
From: "Johnson, Phillip" <phillip.johnson@lmco.com>
Subject: RE: COZY: vacuum source

Al Wick wrote: >Bruce Frank from another newsgroup suggested using the
exhaust pipe to
develop vacuum for my 2 instruments. <end

I have this in my configuration. Being a six cylinder engine I have
connected the three exhaust pipes together, from each bank,  at a
collector. This collector also includes the vacuum pipe and a cross over
connection to the other three cylinders. (Al I hope that you have your
four pipes coupled otherwise you will loose a lot of power.) I have two
vacuum sources because I have two collectors. One vacuum source is for
the instruments and the other is to depressurize the crankcase and to
burn the oil vapors.

It's really bad news to ingest the crankcase vapors into the engine like
they do in the automotive industry. You can blow up the engine if you
follow this practice.

>Phillip Johnson

From: "Gary Dwinal" <gdwinal@exploremaine.com>
Subject: Re: COZY: vacuum source
Date: Thu, 25 Nov 1999 09:26:05 -0500

Hi Folks,
   I haven't contributed here for while but I do have some expertise on this
subject from my NASCAR racing days.  Carl is absolutely correct in that this
type of system must also employ an anti-backfire valve between the exhaust
system and the instruments.  These backfire valves are easy to obtain and
install.  ( An in-line diaghram style check valve. )  This system will also
not develop a real strong vacuum at low RPM settings.  I am not sure 2400 to
2600 RPM would create enough vacuum to operate our systems.  Generally this
type of an arrangement is used on high RPM ( racing engines )  to pull
engine crankcase vapors out of the engine.  I do remember reading about
someone using a combination of this type system along with another more
conventional system to achieve the best of both worlds.  Low RPM settings
 altitude let down ) as well as high RPM settings.
Gary Dwinal
----- Original Message -----
From: <cdenk@ix.netcom.com>
To: <jimsower@mindspring.com>; <cozy_builders@canard.com>
Sent: Thursday, November 25, 1999 8:24 AM
Subject: Re: COZY: vacuum source


> With the exhaust source, what safe guards are there to pressurizing the
gyros with corrosive exhaust gases? Could have some
> strange things happening when an engine backfires or false start. Seems
that the way nature tends to equalize things, these
> gases, when shut down for a long period of time would make their way to a
gyro, with not good effects.

From: alwick@juno.com
Date: Thu, 25 Nov 1999 08:18:38 -0800
Subject: Re: COZY: vacuum source

I was wondering about low power settings. Figured I could have computer
automatically switch to manifold vacuum when/if insufficient vacuum.
Better to test and see what I have first though. kiss.
Check valve...... check! 
Vance, did you test this concept years ago and find problems?
Good ideas Phillip. I forgot you had posted something about that a while
back. Sure appreciate you guys sharing. $300 for pump, $300 for pressure
regulator, what a rip!

Thanks again

-al 


On Thu, 25 Nov 1999 09:26:05 -0500 "Gary Dwinal"
<gdwinal@exploremaine.com> writes:
>  I do remember reading about
> someone using a combination of this type system along with another more
> conventional system to achieve the best of both worlds.  Low RPM
settings
>  altitude let down ) as well as high RPM settings.
> Gary Dwinal
>
___________________________________________________________________
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From: "Bruce McElhoe" <brucem@theworks.com>
Subject: Re: COZY: vacuum source
Date: Thu, 25 Nov 1999 09:31:45 -0800

Al,

Sounds like an idea worth testing.  Be sure to test for low revs (ILS
approach, throttled back to follow glide-slope).

I saw a guy at OSH peddling a back-up vacuum system using a small block
installed above the carb with a port to intake vacuum.   Seemed like a good
idea until I realized that a failure in the suction line might cause the
engine to run lean (or not at all), a "single point of failure".  I only
have one carb, and I don't like messing with the Lycoming induction system.
However, this may not be so critical with your Subaru.

Bruce McElhoe             Long-EZ  N64MC
Reedley, California

Al Wick wrote:
> Bruce Frank from another newsgroup suggested using the exhaust pipe to
> develop vacuum for my 2 instruments. Accomplished by inserting small diam
> tube at angle into pipe. Reportedly exhaust rushing by tube pulls
> substantial vacuum. Enough to overrev gyro.
> Anyone familiar with this technique? I used similar method to make
> machine gun for my RC plane years ago. Worked well.
> I've got all the goodies to test it. Regulator, check valve, inlet
> filter. Thought I'd test w/o instrument hooked up initially. Whatcha
> think?



Date: Thu, 25 Nov 1999 16:35:12 -0500
From: "Johnson, Phillip" <phillip.johnson@lmco.com>
Subject: Re: COZY: vacuum source

Bruce McElhoe Writes> However, this may not be so critical with your
Subaru.<end

If the Subaru uses the stock EFI system then there is a complication.
All air that enters the engine must be metered through the mass airflow
sensor thus to use this as a vacuum source two pipes are necessary
instead of the usual one. This second pipe connects to the
pressure/vacuum regulator back to the engine side of the mass airflow
sensor so that the vacuum air is metered in the mass airflow sensor then
moves on to the instruments then back to the induction manifold. This is
a complicated route using two large vacuum pipes running front to rear.
It is possible to get away without this secondary pipe because the
oxygen sensor will adjust the mixture to compensate however if there is
a failure to the oxygen sensor then the open loop condition will be way
out to lunch. i.e. bad news. Since the manifold vacuum method is only
good for low power operation there needs to be some sort of shuttle
valve to switch between the induction and the exhaust method and this is
getting very complicated since the exhaust driven vacuum system does not
want the second pipe and the induction does want the second pipe.

For those wanting IMC capability in an auto engined aircraft the
simplest route is the electric gyro's however there is an alternative;
There are a number of after market EFI/ignition systems that do not use
the mass airflow sensor to meter the air intake. These systems use the
Manifold Absolute Pressure MAP (the same thing as we all know as
manifold pressure), and the temperature. The engine has to be mapped for
volumetric efficiency but that is relatively easy to do. Once this is
done an oxygen sensor may be used to close the loop and optimize
efficiency or run open loop, the choice is yours. Now with this
configuration you can have all the air leaks you want around the
throttle body and it wont make any difference. Just don't have any air
inputs once the air has divided into the induction runner otherwise you
will have an unbalanced system. BTW the after market EFI/Ignition
systems cost about $1000 (which is still less than an Elison carb) to
$2000. 


Phillip Johnson

Date: Fri, 26 Nov 1999 00:35:19 -0500
From: Jim Sower <jimsower@mindspring.com>
Subject: Re: COZY: vacuum source

I think that's why God gave us accumulators and burp valves and the like.

cdenk@ix.netcom.com wrote:

> With the exhaust source, what safe guards are there to pressurizing the gyros with corrosive exhaust gases? Could have some
> strange things happening when an engine backfires or false start. Seems that the way nature tends to equalize things, these
> gases, when shut down for a long period of time would make their way to a gyro, with not good effects.

From: "Wilhelmson, Jack" <Wilhelmson@scra.org>
Subject: RE: COZY: vacuum source
Date: Wed, 1 Dec 1999 10:50:00 -0500 

This is a solution,  The all electric panel with the backup alternator that
B&C sells is a even better one.

This solution is only good if cost is not a consideration. Electric gyros
are very expensive.

A comparison of the cost of a standard vac system versus an all electric
panel would be an interesting
Subject for this group I am sure.

Jack Wilhelmson N711CZ

	-----Original Message-----
	From:	Paul Comte [SMTP:pcomte@thepark.net]
	Sent:	Tuesday, November 30, 1999 5:27 PM
	To:	Cozy Builders
	Subject:	COZY: vacuum source

	Not to be a wet blanket on this great thread...

	Wouldn't these Canard AC be safer with a backup electric gyro
powered by a
	backup battery?

	Thinking about the complexity of adding this vac stuff and running
it to the
	panel it seems like there is less engineering and maintenance with a
small
	battery and charging circuit driving the backup panel.

	Paul Comte
	Milwaukee, WI 

From: "tcarrico" <tcarrico@home.com>
Subject: RE: COZY: vacuum source
Date: Thu, 2 Dec 1999 06:17:02 -0600

I have seen drag cars with this mod.  Apparently the cams they
were using did not generate enough vacuum at idle, and the tremendous
vacuum they got at full power was supposed to help seal the cylinder.

Don't know if it was fact or fiction, but they used check-valves to 
prevent reverse flow.  I am sure you would need a regulator of some 
sort, but the check valves may not be fast enough to stop hot
exhaust from getting to your gyros.

Good luck, and let us know how it comes along.

tc
>-----Original Message-----
>From: owner-cozy_builders@betaweb.com
>[mailto:owner-cozy_builders@betaweb.com]On Behalf Of Jim Sower
>Sent: Thursday, November 25, 1999 12:05 AM
>To: cozy_builders@canard.com
>Subject: Re: COZY: vacuum source
>
>
>I bet it'd work great.  I do believe I'll look into it myself 
>here directly.
>Why spend the $$ on vacuum pump when lots more interesting stuff can be
>mounted on that pad.  Of course if you have engine failure in 
>IMC ... ;-) ..
>but the regular pump would go then too.
>Don't nobody live forever.  It's a great idea.  Hope it works.   Jim S.
>
>alwick@juno.com wrote:
>
>> Bruce Frank from another newsgroup suggested using the 
>exhaust pipe to
>> develop vacuum for my 2 instruments. Accomplished by 
>inserting small diam
>> tube at angle into pipe. Reportedly exhaust rushing by tube pulls
>> substantial vacuum. Enough to overrev gyro.
>> Anyone familiar with this technique? I used similar method to make
>> machine gun for my RC plane years ago. Worked well.
>> I've got all the goodies to test it. Regulator, check valve, inlet
>> filter. Thought I'd test w/o instrument hooked up initially. Whatcha
>> think?
>>
>> -al wick
>> Canopy Latch System guy.
>> Artificial intelligence in Cockpit
>> Cozy sn 389 driven by stock Subaru 2.5 ltr 106% complete, 
>Aug 00 first
>> flight sched..
>>
>> ___________________________________________________________________
>> Get the Internet just the way you want it.
>> Free software, free e-mail, and free Internet access for a month!
>> Try Juno Web: http://dl.www.juno.com/dynoget/tagj.
>

Date: Thu, 25 Nov 1999 09:35:17 +0200
From: Jannie Versfeld <qmain@intekom.co.za>
Subject: Re: COZY: vacuum source

alwick@juno.com wrote:
> 
> Bruce Frank from another newsgroup suggested using the exhaust pipe to
> develop vacuum for my 2 instruments. 

A couple of EAA'ers here in SA has suggested using an alternator from a
turbo charged diesel pick-up since it has a vaccum pump to operate the
brakes.

I own a Isuzu Pick-Up and after scrutenizing teh altenator it turns out
that it turns in the oppposite direction.  It can be corrected by
swinging the pump body thru 90 degrees wich would let it run in the
reverse direction.

Altenators charge in any direction of rotation.

I am definately going to investigate this further.

Kind regards,
Jannie Versfeld
Cozy MKIV #673


From: cdenk@ix.netcom.com
Date: Sun, 5 Dec 1999 09:07:18 -0500 (EST)
Subject: Re: COZY: vacuum source

DIesel pickup alternator/vacuum pump

What is the weight of the unit?
WHat is the vacuum input capacity compared to required, at what vacuum pressure? The size of the vacuum hose commection, might 
give some hint of this. Most aircraft have a 5/8" tube.

From: alwick@juno.com
Date: Sun, 5 Dec 1999 09:07:09 -0800
Subject: Re: COZY: vacuum source

Have heard of these diesel pumps used successfully.

Update on using engine exhaust as source:

Bruce Frank has since installed this sys in his vehicle. He can achieve
9" hg, but has it regulated to 5". Now has it running his two gyros
mounted in his vehicle. As I recall, he gets 3" at 1200 rpm. This makes
in entirely feasible for my application.
His best results using 3/8 x .065 wall ss tubing. Bend at 90 deg insert
into exhaust. Outlet is flared.
System components, inlet filter (std), vacuum regulator (I like $20
version myself), and anti-backfire valve. Saves you 3 lbs (pump) and
$300+. $2k savings if you consider elect gyro.
Since this is a new system, some risk involved. I could see someone
making tube too long and risking fatigue of ss. Or perhaps choosing to
mod exhaust in way that increases fatigue of exhaust. But using std
industry practice of drilling hole in exhaust, welding a "half steel pipe
coupler" in place should be low risk. Millions of vehicles have exhaust
heat measured that way, no failures.
This is definitely the direction I'll take. I'll do a little
experimentation on it, but not much.
Thanks Vance and everyone for the ideas!

-al wick
Canopy Latch System guy.
Artificial intelligence in cockpit, powered by Subaru.
Now wiring. Aug 2000 first flight scheduled

On Thu, 25 Nov 1999 09:35:17 +0200 Jannie Versfeld <qmain@intekom.co.za>
writes:
> A couple of EAA'ers here in SA has suggested using an alternator from a
> turbo charged diesel pick-up since it has a vaccum pump to operate the
> brakes.
>

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Date: Tue, 14 Dec 1999 10:33:34 -0500 (EST)
From: Richard William Crapse <rwcrapse@unity.ncsu.edu>
Subject: RE: COZY: vacuum source 

In response to your email postings, I would suggest and caution you to be
careful here. Yes, the exhaust rushing through the pipe does create a
decent vacuum source, it is a pulsating vacuum (sp?). What I would
recommend is the following arrangement: a check valve, a metal pipe (
small diameter) , and a vacuum canister. This would allow some advantages.
1. the check valve is needed at low RPM. (ref Subaru emissions control)
2. the metal pipe from the exhaust pipe that you tap, preferably 2 exhaust
stacks feeding through the pipe. The also helps cool the temp down for a
neoprene hose further upline to tap to the metal pipe, compensating for
vibrations and movement.
3. the final piece of the puzzle. The vacuum canister allows some overhead
for "extra" vacuum to be stored. This also buffers your instruments from a
pulsating vacuum. Think of it sort of like an electronic capacitor.

My $0.02 worth.

Rick
Rebuilding workshop 

'All the power in the Universe, but an itty,bitty,little living space'----
                                                         Aladin(genie)
'If it 's got wings, I'll fly it'--Pilot

'And let me know when Elvis shows up...'----Beldar Conehead

'If a shoebox had wings, I'd make it fly!'---The Rocketeer


From: alwick@juno.com
Date: Tue, 14 Dec 1999 16:43:10 -0800
Subject: Re: COZY: vacuum source

On Tue, 14 Dec 1999 10:33:34 -0500 (EST) Richard William Crapse
<rwcrapse@unity.ncsu.edu> writes:
> 3. the final piece of the puzzle. The vacuum canister allows some
overhead
> for "extra" vacuum to be stored. This also buffers your instruments
from a
> pulsating vacuum. Think of it sort of like an electronic capacitor.

Rick, I assume your suggestions are speculative?
I just re-mounted my engine yesterday, and will test this vacuum source.
I have a vacuum accumulator (capacitor), but will be very surprised if it
is needed. I would expect the pulses to be insignificant, given the
frequency.  Additionally, even if pulses reach the gages, I can't think
of a good reason to assume they would be harmful. The flow and pressure
differential are merely a power source for accelerating the gyro. If it
sees a temporary increase, the inertia of the gyro would buffer it. Yes?
Regardless, I'll check it all out in next week or two. If it looks good,
I may even hook up my instruments (assuming the backorder is filled).
I did find that my two gyros need 4 cfm at 4" hg..   Also, 10 feet of
5/8" tubing represents pressure drop of only .2" hg. Still haven't found
5/8" plastic tubing.

-al wick
Canopy Latch System guy.
Artificial intelligence in cockpit, powered by Subaru.
Now wiring. Aug 2000 first flight scheduled

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