---------------------------------------------------------- Continental-List Digest Archive --- Total Messages Posted Mon 11/30/15: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 05:12 PM - [Please Read] - Last Official Day of List Fund Raiser! (Matt Dralle) 1. 12:32 PM - Re: Exhaust Pipe Size (FLYaDIVE) 2. 03:50 PM - Re: Exhaust Pipe Size (Tim Yoder) 3. 05:19 PM - Re: Exhaust Pipe Size (FLYaDIVE) 4. 10:13 PM - Re: Exhaust Pipe Size (Peter Johnson) ________________________________ Message 0 _____________________________________ Time: 05:12:24 PM PST US From: Matt Dralle Subject: Continental-List: [Please Read] - Last Official Day of List Fund Raiser! Dear Listers, It's November 30th and that always means a couple of things. Its my birthday again - 52, so don't remind me! :-) But it also means that it's that last official day of the Matronics Email List Fund Raiser! If you been thinking about picking up one of those really nice incentive gifts now is the time to jump on it!! If you've been meaning to make a Contribution this month but have been putting it off for some reason, NOW is the time! I will be posting the List of Contributors in a few days, so you'll probably want to be known as a person that supported the Lists! I want to thank everyone that has so generously made a Contribution this year in support of our Lists. It is your generosity that keeps this operation running and I don't ever forget it. The List Contribution Web Site is fast and easy. Please support our habit by making your Contribution right now: http://www.matronics.com/contribution Or, by dropping a personal check in the mail to: Matt Dralle / Matronics 581 Jeannie Way Livermore CA 94550 USA Thank you in advance! Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 12:32:16 PM PST US Subject: Re: Continental-List: Exhaust Pipe Size From: FLYaDIVE Peter: There is no simple answer, well, in a way there is: YES! It would, it should, decrease the flow resistance. BUT! Is it worth it? Use the basic formulas for fluid dynamics and you will see that there is a lowering of resistance. BUT! Then you have to work out the formulas for Open End Resonance to see if the exhaust at the end of the pipe is at a Null or a Peak? The other question I would ask, because it is not clear in the picture is: Do you have a CrossOver from the left to the right side? A CrossOver will do more for the system than increasing the size of the pipe. What is the Volume of the Pipe as compared to the Volume of the Cylinder? See what I mean by No Simple Answer? Barry On Sat, Nov 28, 2015 at 6:18 AM, Peter Johnson wrote: > Hi Guys, > > I have an O-200 on my Zodiac 601XLB. I have around 160 hours on the engine. > > I built the exhaust system using 1 1/4 inch tubing for the total system. > > You can see a picture at > http://zodiac.cpc-world.com/images/IMG_0085_JPG.jpg > > Would I get more power if I used 1 1/2 inch tubing from the area where the > two down pipes join? > > Cheers > > Peter > Wonthaggi Australia > > ________________________________ Message 2 _____________________________________ Time: 03:50:56 PM PST US From: "Tim Yoder" Subject: RE: Continental-List: Exhaust Pipe Size Peter, Since you are looking for better performance, along with Barry's comments I would question the prop. Warp Drive and IVO props are not the best design once you get to 100 HP. A two blade wood prop by a manufacturer that has built many for the Cont.0-200 in the Zodiac or a metal prop if you don't want wood would probably make a positive improvement in speed. I flew a 3 blade Warp Drive on my KIS TR-1 with the Cont. IO-240 and got a good 15 mph increase at WOT when I replaced it with a 2 blade wood Sensenich, a Cato will do better than that. I am not familiar with the prop manufacturers in the "Down Under" but you may have choices closer than the USA. I also fly a Thorp T-211 with a Jabiru 3300, it has 625hrs and is running good with a Ed Sterba wood 2 blade. G'day, Tim _____ From: owner-continental-list-server@matronics.com [mailto:owner-continental-list-server@matronics.com] On Behalf Of FLYaDIVE Sent: Monday, November 30, 2015 1:32 PM Subject: Re: Continental-List: Exhaust Pipe Size Peter: There is no simple answer, well, in a way there is: YES! It would, it should, decrease the flow resistance. BUT! Is it worth it? Use the basic formulas for fluid dynamics and you will see that there is a lowering of resistance. BUT! Then you have to work out the formulas for Open End Resonance to see if the exhaust at the end of the pipe is at a Null or a Peak? The other question I would ask, because it is not clear in the picture is: Do you have a CrossOver from the left to the right side? A CrossOver will do more for the system than increasing the size of the pipe. What is the Volume of the Pipe as compared to the Volume of the Cylinder? See what I mean by No Simple Answer? Barry On Sat, Nov 28, 2015 at 6:18 AM, Peter Johnson wrote: Hi Guys, I have an O-200 on my Zodiac 601XLB. I have around 160 hours on the engine. I built the exhaust system using 1 1/4 inch tubing for the total system. You can see a picture at http://zodiac.cpc-world.com/images/IMG_0085_JPG.jpg Would I get more power if I used 1 1/2 inch tubing from the area where the two down pipes join? Cheers Peter Wonthaggi Australia --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 3 _____________________________________ Time: 05:19:57 PM PST US Subject: Re: Continental-List: Exhaust Pipe Size From: FLYaDIVE Very good point about the prop Peter. I did not consider this as Tim's picture shows under construction. It will take a bit of experimentation but if you can find an Aluminum prop something around 70" Diameter and 53" to 57" of Pitch... Put it on and: See what your Static RPM is. It should be 2300 to 2400 RPM. If it is under that take SUBTRACT 1" of Diameter for every 50 RPM until you reach 2300 RPM - - - BUT! Do not go under the recommended diameter. Next: ADD 1" of Pitch until you 2300 RPM. A couple of Prop Rules: Diameter is PULL Pitch is Speed A flat / low pitch is Vertical Speed (VSI) NOW! Remember the Aluminum prop is only for experimentation. All you want to do is collect the numbers- NO cutting or twisting. Then give me the numbers and I will suggest a CATO prop and what Diameter & Pitch for the job. I developed a spreadsheet for the job. NOTE: My numbers are different than what CATO recommends. I developed my spreadsheet from what I found to be Under-Pitched CATO props. AND, if you purchase a CATO make sure you get a Serial Nr on the Prop, and certification for Diameter and pitch; and a Logbook. They are a bit lax on proper paperwork Another point: Weight is a consideration. The CATO prop will be half the weight of the aluminum, this weight savings is HP and Speed. AND unlike the wood you will be able to keep it outside and fly in the rain. Barry On Mon, Nov 30, 2015 at 6:50 PM, Tim Yoder wrote: > Peter, > > Since you are looking for better performance, along with Barry's comments > I would question the prop. Warp Drive and IVO props are not the best design > once you get to 100 HP. A two blade wood prop by a manufacturer that has > built many for the Cont.0-200 in the Zodiac or a metal prop if you don't > want wood would probably make a positive improvement in speed. I flew a 3 > blade Warp Drive on my KIS TR-1 with the Cont. IO-240 and got a good 15 > mph increase at WOT when I replaced it with a 2 blade wood Sensenich, a > Cato will do better than that. I am not familiar with the prop > manufacturers in the "Down Under" but you may have choices closer than the > USA. > > I also fly a Thorp T-211 with a Jabiru 3300, it has 625hrs and is running > good with a Ed Sterba wood 2 blade. > > G'day, Tim > > ------------------------------ > *From:* owner-continental-list-server@matronics.com [mailto: > owner-continental-list-server@matronics.com] *On Behalf Of *FLYaDIVE > *Sent:* Monday, November 30, 2015 1:32 PM > *To:* continental-list@matronics.com > *Subject:* Re: Continental-List: Exhaust Pipe Size > > Peter: > > There is no simple answer, well, in a way there is: YES! > It would, it should, decrease the flow resistance. BUT! > Is it worth it? > Use the basic formulas for fluid dynamics and you will see that there is a > lowering of resistance. BUT! > Then you have to work out the formulas for Open End Resonance to see if > the exhaust at the end of the pipe is at a Null or a Peak? > The other question I would ask, because it is not clear in the picture is: > Do you have a CrossOver from the left to the right side? > A CrossOver will do more for the system than increasing the size of the > pipe. > What is the Volume of the Pipe as compared to the Volume of the Cylinder? > See what I mean by No Simple Answer? > > Barry > > On Sat, Nov 28, 2015 at 6:18 AM, Peter Johnson > wrote: > >> Hi Guys, >> >> I have an O-200 on my Zodiac 601XLB. I have around 160 hours on the >> engine. >> >> I built the exhaust system using 1 1/4 inch tubing for the total system. >> >> You can see a picture at >> http://zodiac.cpc-world.com/images/IMG_0085_JPG.jpg >> >> Would I get more power if I used 1 1/2 inch tubing from the area where >> the two down pipes join? >> >> Cheers >> >> Peter >> Wonthaggi Australia >> >> >> > > > ------------------------------ > [image: Avast logo] > > This email has been checked for viruses by Avast antivirus software. > www.avast.com > > ________________________________ Message 4 _____________________________________ Time: 10:13:58 PM PST US Subject: Re: Continental-List: Exhaust Pipe Size From: Peter Johnson Hi Guys, Thanks for the replies. I don=99t have a crossover pipe between the two sides. Maybe able to add qu ite easily. I have been carrying out some testing with the prop. I have the warp drive set for 9 degrees at the moment and only get 2150rpm static. I=99ll tweak it a little to see if I can get some more static rpm. I do have a wooden prop that came off a O-200 powered tailwind. I=99ll chec k that out as well. Thanks for your responses. Cheers Peter From: on behalf of FLYaDIVE Subject: Re: Continental-List: Exhaust Pipe Size Very good point about the prop Peter. I did not consider this as Tim's pic ture shows under construction. It will take a bit of experimentation but if you can find an Aluminum prop something around 70" Diameter and 53" to 57" of Pitch... Put it on and: See what your Static RPM is. It should be 2300 to 2400 RPM. If it is under that take SUBTRACT 1" of Diameter for every 50 RPM until you reach 2300 RPM - - - BUT! Do not go under the recommended diameter. Next: ADD 1" of Pitch until you 2300 RPM. A couple of Prop Rules: Diameter is PULL Pitch is Speed A flat / low pitch is Vertical Speed (VSI) NOW! Remember the Aluminum prop is only for experimentation. All you want to do is collect the numbers- NO cutting or twisting. Then give me the numbers and I will suggest a CATO prop and what Diameter & Pitch for the job. I developed a spreadsheet for the job. NOTE: My numbers are different than what CATO recommends. I developed my spreadsheet from what I found to be Under-Pitched CATO props. AND, if you pu rchase a CATO make sure you get a Serial Nr on the Prop, and certification f or Diameter and pitch; and a Logbook. They are a bit lax on proper paperwor k Another point: Weight is a consideration. The CATO prop will be half the weight of the aluminum, this weight savings is HP and Speed. AND unlike the wood you will be able to keep it outside and fly in the rain. Barry On Mon, Nov 30, 2015 at 6:50 PM, Tim Yoder wrote: Peter, Since you are looking for better performance, along with Barry's comments I would question the prop. Warp Drive and IVO props are not the best design o nce you get to 100 HP. A two blade wood prop by a manufacturer that has buil t many for the Cont.0-200 in the Zodiac or a metal prop if you don't want wo od would probably make a positive improvement in speed. I flew a 3 blade War p Drive on my KIS TR-1 with the Cont. IO-240 and got a good 15 mph increase at WOT when I replaced it with a 2 blade wood Sensenich, a Cato will do bet ter than that. I am not familiar with the prop manufacturers in the "Down Un der" but you may have choices closer than the USA. I also fly a Thorp T-211 with a Jabiru 3300, it has 625hrs and is running g ood with a Ed Sterba wood 2 blade. G'day, Tim From: owner-continental-list-server@matronics.com [mailto:owner-continental -list-server@matronics.com] On Behalf Of FLYaDIVE Sent: Monday, November 30, 2015 1:32 PM Subject: Re: Continental-List: Exhaust Pipe Size Peter: There is no simple answer, well, in a way there is: YES! It would, it should, decrease the flow resistance. BUT! Is it worth it? Use the basic formulas for fluid dynamics and you will see that there is a lowering of resistance. BUT! Then you have to work out the formulas for Open End Resonance to see if the exhaust at the end of the pipe is at a Null or a Peak? The other question I would ask, because it is not clear in the picture is: Do you have a CrossOver from the left to the right side? A CrossOver will do more for the system than increasing the size of the pip e. What is the Volume of the Pipe as compared to the Volume of the Cylinder? See what I mean by No Simple Answer? Barry On Sat, Nov 28, 2015 at 6:18 AM, Peter Johnson wrot e: Hi Guys, I have an O-200 on my Zodiac 601XLB. I have around 160 hours on the engine .. I built the exhaust system using 1 1/4 inch tubing for the total system. You can see a picture at http://zodiac.cpc-world.com/images/IMG_0085_JPG.jp g Would I get more power if I used 1 1/2 inch tubing from the area where the two down pipes join? Cheers Peter Wonthaggi Australia This email has been checked for viruses by Avast antivirus software. www.avast.com ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message continental-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Continental-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/continental-list Browse Digests http://www.matronics.com/digest/continental-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.