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" 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" 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" 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 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" 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. Phillip Johnson From: "Gary Dwinal" 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: To: ; 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" 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 > ___________________________________________________________________ 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: "Bruce McElhoe" 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" Subject: Re: COZY: vacuum source Bruce McElhoe Writes> However, this may not be so critical with your Subaru. 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" 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" 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 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 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. > ___________________________________________________________________ Why pay more to get Web access? Try Juno for FREE -- then it's just $9.95/month if you act NOW! Get your free software today: http://dl.www.juno.com/dynoget/tagj. Date: Tue, 14 Dec 1999 10:33:34 -0500 (EST) From: Richard William Crapse 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 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 ___________________________________________________________________ Why pay more to get Web access? Try Juno for FREE -- then it's just $9.95/month if you act NOW! Get your free software today: http://dl.www.juno.com/dynoget/tagj.