---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Tue 11/29/05: 10 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:14 AM - Hey Guys... (Matt Dralle) 2. 05:31 AM - Re: Re: manifold pressure (linn walters) 3. 05:43 AM - Re: Re: manifold pressure () 4. 06:01 AM - Re: Re: manifold pressure (linn walters) 5. 07:01 AM - Re: AOPA Tiger article (flyv35b) 6. 12:00 PM - Re: Re: manifold pressure (TeamGrumman@AOL.COM) 7. 12:02 PM - Re: Re: manifold pressure (TeamGrumman@AOL.COM) 8. 12:46 PM - Re: Re: manifold pressure (linn walters) 9. 12:51 PM - Re: Re: manifold pressure (linn walters) 10. 01:02 PM - Re: Re: manifold pressure (TeamGrumman@AOL.COM) ________________________________ Message 1 _____________________________________ Time: 12:14:03 AM PST US From: Matt Dralle Subject: TeamGrumman-List: Hey Guys... --> TeamGrumman-List message posted by: Matt Dralle Hey guys, wow, I can't believe all the really nice comments I've been getting about how much you appreciate and enjoy the Lists. I really appreciate your positive feedback and support. I've included below a bunch more of the awesome feedback I've received in the last week or so. Please read over some of these great comments. It is really quite amazing... There are just a couple more days left during this year's Fund Raiser and your chance to get one of the really great gifts. If you been putting off making a Contribution, now's your chance to support these Lists *and* pinch an awesome free gift too! Thank you to everyone that has made a Contribution already. It is much appreciated! http://www.matronics.com/contribution Best regards, Matt Dralle List Admininstrator ----------------------- Lister Comments ----------------------- The Archives Search Engine is usually the first place I turn to when I run into a building question or problem I need to resolve. Christopher H. I look forward so much to reading the list digest every night that my wife thinks I'm getting obsessed. Thomas S. It's also the way I start my day. 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I'd feel guilty all year if I didn't contribute. Brian U. It has helped me be a better builder and put me in touch with some real fine people. Bruce B. A great list!!! Rupert T. ...invaluable help to many builders. Jonathan R. Great list, I'm still trying to decide, and the List provides great information. Maarten V. Your web sites provide me with an important connection to invaluable technical resources plus feedback and motivation to continue the build process. Douglas D. A great resource and contribution to safety. Donald K. A great service. Richard R. It has been a source for a lot of useful information over the many years I have been on the list. Jerry S. I really enjoy the positive spirit and exchange via your List. Richard R. The List has been a great help on several occasions... Harry C. Great List! Reginald D. The knowledge and support that I have received from your members was worth more that my contribution. Valerie W. It has also been a source of great entertainment at times. Jerry S. ...always a source of amusement. Harry C. I'm still under construction and the list has helped me avoid many problems. Rupert T. ----------------------- Lister Comments ----------------------- Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft do not archive ________________________________ Message 2 _____________________________________ Time: 05:31:56 AM PST US From: linn walters Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: linn walters I'm not communicating. The burps start during the leaning process (see the second set of EGT's) and are once every 30 to 60 seconds apart. When you look at the display, the readings 'hunt' around a number ..... which is what I try to record. The reading on a particular cylinder may fluctuate a couple of points when everything is stable ..... no changes being made. As I leaned and took data, the rate of burps went up ...... around 15 seconds or so at full lean. It was still easy to distinguish the burps from normal engine roughness as I over-leaned ..... way into power loss. I took 8 sets of data, every two turns of the mixture knob until 10 turns and then took readings at 1 turn. The difference in EGTs below shows that the burps start about one turn before leaning really takes off (10 turns), and is lean at 11 turns and over-lean at 12 turns where we stopped taking data. I'll take data again, but cut the changes down to 1/4 turn when the burping starts because I don't have enough data points to really get a good curve right now. When looking at the EGTs and trying to see which cylinder EGT changes in sync with the burps is nearly impossible as the reading changes +/- (let's say one for the sake of argument going from 1440 to 1441 to 1440 to 1339 to 1440 ..... that sort of thing) and there doesn't seem to be any change in correlation with the burps. This weekend when we fly a Toys for Tots mission, I'll try and get some more data. Problem is that the flights are around 1/2 hour and Sunday's flight was the first I participated in. Any ideas yet??? Linn do not archive TeamGrumman@aol.com wrote: >--> TeamGrumman-List message posted by: TeamGrumman@aol.com > >It looks to me like the EGTs were 15 to 30 degrees lower. > > > >>Whoa.=A0 I may have mis-typed!!!=A0 There is no drop in EGTs when the burps >>occur.=A0 The engine monitor will float +/- a couple of points when it's >>not burping so it's really hard to see the burp on the EGTs. >> >> >> > >Peak for all 4 were at: > >1=A0=A0 1425 >2=A0=A0 1465 >3=A0=A0 1400 >4=A0=A0 1445 > >If that means anything!!! > >When the burps start, the EGTs were: > >1=A0=A0 1405 >2=A0=A0 1450 >3=A0=A0 1370 >4=A0=A0 1415 > > > > ________________________________ Message 3 _____________________________________ Time: 05:43:53 AM PST US From: Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: Linn, have you tried leaning for the burp with just one mag running? if it burps on both mags when run singularly that sorta eliminates electrical as a source....have heard of a similar thing where a "tang" from a helicoil extending into the cylinder was acting as a glow plug and preigniting the fuel good luck.... Andy Thomas ----- Original Message ----- From: "linn walters" Subject: Re: TeamGrumman-List: Re: manifold pressure > --> TeamGrumman-List message posted by: linn walters > > > I'm not communicating. The burps start during the leaning process (see > the second set of EGT's) and are once every 30 to 60 seconds apart. > When you look at the display, the readings 'hunt' around a number ..... > which is what I try to record. The reading on a particular cylinder may > fluctuate a couple of points when everything is stable ..... no changes > being made. As I leaned and took data, the rate of burps went up ...... > around 15 seconds or so at full lean. It was still easy to distinguish > the burps from normal engine roughness as I over-leaned ..... way into > power loss. I took 8 sets of data, every two turns of the mixture knob > until 10 turns and then took readings at 1 turn. The difference in EGTs > below shows that the burps start about one turn before leaning really > takes off (10 turns), and is lean at 11 turns and over-lean at 12 > turns where we stopped taking data. I'll take data again, but cut the > changes down to 1/4 turn when the burping starts because I don't have > enough data points to really get a good curve right now. > > When looking at the EGTs and trying to see which cylinder EGT changes in > sync with the burps is nearly impossible as the reading changes +/- > (let's say one for the sake of argument going from 1440 to 1441 to 1440 > to 1339 to 1440 ..... that sort of thing) and there doesn't seem to be > any change in correlation with the burps. This weekend when we fly a > Toys for Tots mission, I'll try and get some more data. Problem is that > the flights are around 1/2 hour and Sunday's flight was the first I > participated in. > > Any ideas yet??? > Linn > do not archive > TeamGrumman@aol.com wrote: > >>--> TeamGrumman-List message posted by: TeamGrumman@aol.com >> >>It looks to me like the EGTs were 15 to 30 degrees lower. >> >> >> >>>Whoa.=A0 I may have mis-typed!!!=A0 There is no drop in EGTs when the >>>burps >>>occur.=A0 The engine monitor will float +/- a couple of points when it's >>>not burping so it's really hard to see the burp on the EGTs. >>> >>> >>> >> >>Peak for all 4 were at: >> >>1=A0=A0 1425 >>2=A0=A0 1465 >>3=A0=A0 1400 >>4=A0=A0 1445 >> >>If that means anything!!! >> >>When the burps start, the EGTs were: >> >>1=A0=A0 1405 >>2=A0=A0 1450 >>3=A0=A0 1370 >>4=A0=A0 1415 >> >> >> >> > > > ________________________________ Message 4 _____________________________________ Time: 06:01:49 AM PST US From: linn walters Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: linn walters andy747@charter.net wrote: >--> TeamGrumman-List message posted by: > >Linn, > >have you tried leaning for the burp with just one mag running? > Not yet. That's on the next test flight. Trying to get the other guys to have a test plan and write the data down during a flight is, unfortunately, rather tough. The owner has a current medical but won't fly without another pilot along, so data taking should be easy. They only take a few data points and are constantly in the 'try this' mode, changing too many things at once without any baseline data. Sunday was the first try I had at it, and I've had a lot of good suggestions, many that have been tried before, to visit/re-visit. I've been too busy to actively participate and the others have spent an inordinate amount of time chasing their tails. linn do not archive > >if it burps on both mags when run singularly that sorta eliminates >electrical as a source....have heard of a similar thing where a "tang" from >a helicoil extending into the cylinder was acting as a glow plug and >preigniting the fuel > >good luck.... > >Andy Thomas > >----- Original Message ----- >From: "linn walters" >Subject: Re: TeamGrumman-List: Re: manifold pressure > > > > >>--> TeamGrumman-List message posted by: linn walters >> >> >>I'm not communicating. The burps start during the leaning process (see >>the second set of EGT's) and are once every 30 to 60 seconds apart. >>When you look at the display, the readings 'hunt' around a number ..... >>which is what I try to record. The reading on a particular cylinder may >>fluctuate a couple of points when everything is stable ..... no changes >>being made. As I leaned and took data, the rate of burps went up ...... >>around 15 seconds or so at full lean. It was still easy to distinguish >>the burps from normal engine roughness as I over-leaned ..... way into >>power loss. I took 8 sets of data, every two turns of the mixture knob >>until 10 turns and then took readings at 1 turn. The difference in EGTs >>below shows that the burps start about one turn before leaning really >>takes off (10 turns), and is lean at 11 turns and over-lean at 12 >>turns where we stopped taking data. I'll take data again, but cut the >>changes down to 1/4 turn when the burping starts because I don't have >>enough data points to really get a good curve right now. >> >>When looking at the EGTs and trying to see which cylinder EGT changes in >>sync with the burps is nearly impossible as the reading changes +/- >>(let's say one for the sake of argument going from 1440 to 1441 to 1440 >>to 1339 to 1440 ..... that sort of thing) and there doesn't seem to be >>any change in correlation with the burps. This weekend when we fly a >>Toys for Tots mission, I'll try and get some more data. Problem is that >>the flights are around 1/2 hour and Sunday's flight was the first I >>participated in. >> >>Any ideas yet??? >>Linn >>do not archive >>TeamGrumman@aol.com wrote: >> >> >> >>>--> TeamGrumman-List message posted by: TeamGrumman@aol.com >>> >>>It looks to me like the EGTs were 15 to 30 degrees lower. >>> >>> >>> >>> >>> >>>>Whoa.=A0 I may have mis-typed!!!=A0 There is no drop in EGTs when the >>>>burps >>>>occur.=A0 The engine monitor will float +/- a couple of points when it's >>>>not burping so it's really hard to see the burp on the EGTs. >>>> >>>> >>>> >>>> >>>> >>>Peak for all 4 were at: >>> >>>1=A0=A0 1425 >>>2=A0=A0 1465 >>>3=A0=A0 1400 >>>4=A0=A0 1445 >>> >>>If that means anything!!! >>> >>>When the burps start, the EGTs were: >>> >>>1=A0=A0 1405 >>>2=A0=A0 1450 >>>3=A0=A0 1370 >>>4=A0=A0 1415 >>> >>> >>> >>> >>> >>> >> >> >> > > > > ________________________________ Message 5 _____________________________________ Time: 07:01:30 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: AOPA Tiger article --> TeamGrumman-List message posted by: "flyv35b" I must also say that I was pleasantly surprised after installing a new PF internal muffler on a customers Tiger recently. The short stack internal muffler design is what I felt they should have done in the first place. I measured 60 rpm increase static and 80 rpm increase flying at full throttle at about 3000 ft. altitude. Also the EGT temps where more uniform. There was a very noticeable increase in takeoff and climb performance (I did not have time to take any measurements however). I also feel that the strap support for the outlet muffler offers very little actual support, but is better than none at all. I left the strap installed but added 2 Adel clamps to the lower engine mount tube to better support the outlet muffler. The slip joints on the riser pipes connections to the muffler are a vast improvement over the split beaded clamps on the stock exhaust system. The cowling was slotted completely to the aft edge and one additional nutplate installed to facilitate removing and installing the lower cowling. I can't help but feel that patching the old hole in the cowling will improve cooling air flow and reduce drag and now there is some aft thrust component from the exhaust gases. It even appears as if they won't stain the belly as much as the stock exhaust. Cliff A&P/IA Cascade Country Aviation PowerFlow exhaust system dealer for the NW. ----- Original Message ----- From: Subject: Re: TeamGrumman-List: AOPA Tiger article > --> TeamGrumman-List message posted by: TeamGrumman@aol.com > > > In a message dated 11/28/05 7:13:29 AM, Douglas.Weir@us.calyon.com writes: > > >> Gary, >> Did you also install the PowerFlow exhaust on your plane?=A0 Are you a >> believer? >> >> > > Oh, yes, I forgot to say that. It does have the short stack Power Flow. > The power Flow exhaust system is very well designed right up to where they > attach the muffler to the plane. On the original setup, the muffler > would=20hang > loosely and wobble back and forth. On the short stack, the support brace > is > at such a poor angle that it is useless. > > We had a new 182 Cessna do a hard landing here. When the cowling was > off,=20I > noticed the muffler supported by a bracket mounted to the firewall. > Clearly > a lot better way to support the muffler. SOOOOO, I mounted my short > stack > so that the muffler has a descent support at the firewall. > > Other-than-that, anything beats the poorly designed stock muffler. If I > could replace every stock muffler with the power flow, I would. > > By-the-way, I got an additional 80 rpm at 12,500 feet with the power flow. > > At 17,500 feet, I can still turn it 2650 rpm. > > Gary > > > ________________________________ Message 6 _____________________________________ Time: 12:00:40 PM PST US From: TeamGrumman@AOL.COM Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: TeamGrumman@aol.com You really need an analyzer that you can download the data. Taking data by hand is tenuous at best. It's also very subjective. Am I to understand you have an O-360 with an updraft carb? Not too long after I had the one-piece venturi installed in my Cheetah and had the few instances of burping, I found an overhauler that would put the two-piece back in. I didn't do it. Just contemplated it. Both times it happened I was climbing out of high terrain. Very disconcerting. In a message dated 11/29/05 5:32:30 AM, lwalters2@cfl.rr.com writes: > I'm not communicating.=A0 The burps start during the leaning process (see > the second set of EGT's) and are once every 30 to 60 seconds apart.=A0 > When you look at the display, the readings 'hunt' around a number ..... > which is what I try to record.=A0 The reading on a particular cylinder may > fluctuate a couple of points when everything is stable ..... no changes > being made.=A0 As I leaned and took data, the rate of burps went up ...... > around 15 seconds or so at full lean.=A0 It was still easy to distinguish > the burps from normal engine roughness as I over-leaned ..... way into > power loss.=A0 > ________________________________ Message 7 _____________________________________ Time: 12:02:01 PM PST US From: TeamGrumman@AOL.COM Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: TeamGrumman@aol.com In a message dated 11/29/05 6:02:48 AM, lwalters2@cfl.rr.com writes: > Not yet.=A0 That's on the next test flight.=A0 > so, not a Grumman I take it ...... ________________________________ Message 8 _____________________________________ Time: 12:46:31 PM PST US From: linn walters Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: linn walters TeamGrumman@aol.com wrote: >--> TeamGrumman-List message posted by: TeamGrumman@aol.com > >You really need an analyzer that you can download the data. > AMEN!!! > Taking data by hand is tenuous at best. It's also very subjective. > True, but how do you get the data acquisition type analyzer to hear and feel the burp??? :-P >Am I to understand you have an O-360 with an updraft carb? > Yes > Not too long >after I had the one-piece venturi installed in my Cheetah and had the few >instances of burping, I found an overhauler that would put the two-piece back in. I >didn't do it. Just contemplated it. Both times it happened I was climbing >out of high terrain. Very disconcerting. > This is one question I failed to ask of the owner/pilot. They've been working on things for months .... all engine related ..... and so much is new/rebuilt/blessed that I can't keep up. I'll the venturi question to my list. That's a possibility since the carb was rebuilt recently. One way to get around problems like the venturi and floats .... is to request a 'repair' rather than an overhaul. But you knew that, didn't you :-) . Linn do not archive -- ________________________________ Message 9 _____________________________________ Time: 12:51:01 PM PST US From: linn walters Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: linn walters TeamGrumman@aol.com wrote: >so, not a Grumman I take it ...... > I've been found out. No, it's on a Glastar. The reason I posed this to the Gang (and Teamgrumman) is because I value their knowledge ...... and am sure of getting solid information. Posing the question on another list (say Lycoming) would elicit responses from unknown sources ..... and I wouldn't know whether the info was factual, speculation, or even malicious. Linn do not archive -- ________________________________ Message 10 ____________________________________ Time: 01:02:44 PM PST US From: TeamGrumman@AOL.COM Subject: Re: TeamGrumman-List: Re: manifold pressure --> TeamGrumman-List message posted by: TeamGrumman@aol.com do you know if the mags are rebuilt mags or new ones? if you can look into the throat of the carb, look to see if the atomizer looks like it's perforated. It's the thing in the middle of the venturi. I changed mine at about the time of my burps for shits-and-grins along with a whole lot of other stuff. Bad trouble shooting/experimental technique I know, but I was desparate. A shotgun approach seemed the most prudent.