---------------------------------------------------------- Engines-List Digest Archive --- Total Messages Posted Wed 06/28/06: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:02 AM - Single electronic ignition (Gary Casey) 2. 06:30 AM - Re: Exhaust ball joints...... (flyv35b) 3. 06:33 AM - Re: Single electronic ignition (flyv35b) 4. 07:00 AM - Re: Single electronic ignition (jrc) 5. 07:06 AM - Re: Single electronic ignition (Ken Johnson) 6. 07:22 AM - Re: Single electronic ignition (Gary Casey) 7. 07:30 AM - Re: Re: Single electronic ignition (BPA) 8. 07:36 AM - Re: Single electronic ignition (Tracy Crook) 9. 08:22 AM - Re: Single electronic ignition (Craig Berland) 10. 10:52 AM - Re: Single electronic ignition (steve korney) 11. 10:55 AM - Re: Re: Single electronic ignition (steve korney) 12. 11:07 AM - Re: Re: Single electronic ignition (steve korney) 13. 01:05 PM - Re: Single electronic ignition (J. R. Dial) ________________________________ Message 1 _____________________________________ Time: 06:02:21 AM PST US From: Gary Casey Subject: Engines-List: Single electronic ignition --> Engines-List message posted by: Gary Casey I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag and one Lightspeed ignition. I now have about 5 flight hours on the engine. The engine was set up with 25 degrees timing on both ignitions, but I was worried about peak cylinder pressures and retarded the mag to about 21.5 degrees. Runups are a problem in that there is a slight drop going to the electronic ignition (I expected that), but a drop of maybe 300 rpm from 1700 on the mag and running on the mag almost always misfires until I run lean for several seconds to dry out the plugs. The misfire situation is getting better, I assume because the engine is breaking in and using less oil and partly because I'm doing less ground running than before. I'm wondering if the large mag drop is normal, possibly because the Lightspeed is giving quite a bit of advance during runup because of the low manifold pressure (I forgot to read the MAP during runup). Doe anyone know what the advance "curve" looks like for the Lightspeed? I understand others have asked for an official answer and it was supposedly "proprietary", but I also understand you can get a readout from Lightspeed that gives the actual advance. All one would have to do is plot the displayed number against rpm and MAP to extract the algorithm. Anyone done that? If I wanted to reduce the advance on the Lightspeed by maybe 5 degrees is there a simple way to do that? I don't have any travel in that direction on the pickup plate and I don't want to retard the cranking advance. Gary Casey ________________________________ Message 2 _____________________________________ Time: 06:30:04 AM PST US From: "flyv35b" Subject: Re: Engines-List: Exhaust ball joints...... --> Engines-List message posted by: "flyv35b" The Bonanza also uses a 3 bolt ball joint coupling with springs. I would bet that they would also work and should be readily available. Cliff ----- Original Message ----- Sent: Tuesday, June 27, 2006 3:21 PM > --> Engines-List message posted by: "Dale Fultz" > > I have a set of Cessna bolts and springs and nuts I believe there is 3 of > each would have to look for sure. I will sell ,, Make me an offer ...Dale > Fultz > ----- Original Message ----- > Sent: Tuesday, June 27, 2006 5:40 PM > > >> --> Engines-List message posted by: "Jim Baker" >> >> I'm a Viking driver and am having a rebuilt engine shipped from >> Cont. shortly. The issue is this...the original Bellanca exhaust >> used a V clamp on the tailpipe/header joint and I'm having that >> modified to a ball joint w/triangular flanges and bolts/springs as >> the retainers, similar to the mod the Bellanca factory made >> around '76. My problem is the "factory" no longer really exists >> and parts/specs are unavailable, even from other Bellanca >> specialists. I have the bolt length/size but don't have the spring >> specs and they're no longer available. I'm told that these are >> probably the same as used on Cessna 210 and 206 models. >> Anyone have the spring part number or specs? Also told that >> these are Wall Colmonoy 650K ball kits but haven't talked to >> them to see if they included the bolts/springs or just the joint kits. >> >> Thanks. >> >> Jim Baker >> 580.788.2779 >> Elmore City, OK >> >> >> >> >> >> >> >> >> >> >> >> >> >> > > > http://www.matronics.com/Navigator?Engines-List > http://wiki.matronics.com > > > ________________________________ Message 3 _____________________________________ Time: 06:33:28 AM PST US From: "flyv35b" Subject: Re: Engines-List: Single electronic ignition --> Engines-List message posted by: "flyv35b" Very interesting comments and questions. I would be interested in knowing the answers when you find out some more info. How are you CHT's and oil temperature with the 10:1 pistons? What kind of plane is the engine in? Cliff A&P/IA ----- Original Message ----- Sent: Wednesday, June 28, 2006 5:57 AM > --> Engines-List message posted by: Gary Casey > > I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag > and one Lightspeed ignition. I now have about 5 flight hours on the > engine. The engine was set up with 25 degrees timing on both ignitions, > but I was worried about peak cylinder pressures and retarded the mag to > about 21.5 degrees. Runups are a problem in that there is a slight drop > going to the electronic ignition (I expected that), but a drop of maybe > 300 rpm from 1700 on the mag and running on the mag almost always > misfires until I run lean for several seconds to dry out the plugs. The > misfire situation is getting better, I assume because the engine is > breaking in and using less oil and partly because I'm doing less ground > running than before. I'm wondering if the large mag drop is normal, > possibly because the Lightspeed is giving quite a bit of advance during > runup because of the low manifold pressure (I forgot to read the MAP > during runup). Doe anyone know what the advance "curve" looks like for > the Lightspeed? I understand others have asked for an official answer > and it was supposedly "proprietary", but I also understand you can get a > readout from Lightspeed that gives the actual advance. All one would > have to do is plot the displayed number against rpm and MAP to extract > the algorithm. Anyone done that? If I wanted to reduce the advance on > the Lightspeed by maybe 5 degrees is there a simple way to do that? I > don't have any travel in that direction on the pickup plate and I don't > want to retard the cranking advance. > > Gary Casey > > > http://www.matronics.com/Navigator?Engines-List > http://wiki.matronics.com > > > ________________________________ Message 4 _____________________________________ Time: 07:00:21 AM PST US From: "jrc" Subject: Re: Engines-List: Single electronic ignition --> Engines-List message posted by: "jrc" To me, a 300 rpm drop sounds about normal for a mag set to 21.5 degrees. Have you thought about setting it back to 25, in order to reduce the drop and the misfiring? ----- Original Message ----- Sent: Wednesday, June 28, 2006 7:57 AM > --> Engines-List message posted by: Gary Casey > > I was worried about peak cylinder pressures and retarded the mag to about > 21.5 degrees. ....., but a drop of maybe 300 rpm...on the mag ________________________________ Message 5 _____________________________________ Time: 07:06:26 AM PST US From: "Ken Johnson" Subject: Re: Engines-List: Single electronic ignition --> Engines-List message posted by: "Ken Johnson" Gary, What aircraft is your Lightspeed system in? I have a Glasair III , IO-540K1A5 angle valve with Klaus' system replacing one mag for a period of time as I built the courage to install both Lightspeed systems. One electronic unit works better than none. Two are far superior in all parameters. I now have about six or eight years and several hundred hours on Klaus' units and have found them to be totally reliable and trouble free. Don't mean to sound like a salesman but if you want to contact me by phone I would be glad to discuss this topic. Regards, Ken Johnson ----- Original Message ----- Sent: Wednesday, June 28, 2006 8:57 AM > --> Engines-List message posted by: Gary Casey > > I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag > and one Lightspeed ignition. I now have about 5 flight hours on the > engine. The engine was set up with 25 degrees timing on both ignitions, > but I was worried about peak cylinder pressures and retarded the mag to > about 21.5 degrees. Runups are a problem in that there is a slight drop > going to the electronic ignition (I expected that), but a drop of maybe > 300 rpm from 1700 on the mag and running on the mag almost always > misfires until I run lean for several seconds to dry out the plugs. The > misfire situation is getting better, I assume because the engine is > breaking in and using less oil and partly because I'm doing less ground > running than before. I'm wondering if the large mag drop is normal, > possibly because the Lightspeed is giving quite a bit of advance during > runup because of the low manifold pressure (I forgot to read the MAP > during runup). Doe anyone know what the advance "curve" looks like for > the Lightspeed? I understand others have asked for an official answer > and it was supposedly "proprietary", but I also understand you can get a > readout from Lightspeed that gives the actual advance. All one would > have to do is plot the displayed number against rpm and MAP to extract > the algorithm. Anyone done that? If I wanted to reduce the advance on > the Lightspeed by maybe 5 degrees is there a simple way to do that? I > don't have any travel in that direction on the pickup plate and I don't > want to retard the cranking advance. > > Gary Casey > > > http://www.matronics.com/Navigator?Engines-List > http://wiki.matronics.com > > > ________________________________ Message 6 _____________________________________ Time: 07:22:05 AM PST US From: Gary Casey Subject: Engines-List: Re: Single electronic ignition --> Engines-List message posted by: Gary Casey I forgot to mention - one characteristic of this setup is that when going LOP at 10% less fuel flow than at peak the EGT's will drop less than 50 degrees(F) before they start going up again. At that time the engine is obviously on the ragged edge and will start to run very rough, occasionally even back-firing. I haven't seen - or haven't noticed - this upward EGT trend and such a sharp lean limit on other engines. Is it because of the higher compression? Should I worry? Gary Casey On Jun 28, 2006, at 5:57 AM, Gary Casey wrote: > I have a IO-540 parallel-valve with 10:1 compression, a single > Slick mag and one Lightspeed ignition. I now have about 5 flight > hours on the engine. The engine was set up with 25 degrees timing > on both ignitions, but I was worried about peak cylinder pressures > and retarded the mag to about 21.5 degrees. Runups are a problem > in that there is a slight drop going to the electronic ignition (I > expected that), but a drop of maybe 300 rpm from 1700 on the mag > and running on the mag almost always misfires until I run lean for > several seconds to dry out the plugs. The misfire situation is > getting better, I assume because the engine is breaking in and > using less oil and partly because I'm doing less ground running > than before. I'm wondering if the large mag drop is normal, > possibly because the Lightspeed is giving quite a bit of advance > during runup because of the low manifold pressure (I forgot to read > the MAP during runup). Doe anyone know what the advance "curve" > looks like for the Lightspeed? I understand others have asked for > an official answer and it was supposedly "proprietary", but I also > understand you can get a readout from Lightspeed that gives the > actual advance. All one would have to do is plot the displayed > number against rpm and MAP to extract the algorithm. Anyone done > that? If I wanted to reduce the advance on the Lightspeed by maybe > 5 degrees is there a simple way to do that? I don't have any > travel in that direction on the pickup plate and I don't want to > retard the cranking advance. > > Gary Casey ________________________________ Message 7 _____________________________________ Time: 07:30:23 AM PST US From: "BPA" Subject: RE: Engines-List: Re: Single electronic ignition --> Engines-List message posted by: "BPA" Gary: Have you contacted your engine builder? They should be able to provide you with detailed information and help trouble shoot your concerns. Regards, Allen Barrett Barrett Precision Engines, Inc. 2870-B N. Sheridan Rd. Tulsa, OK 74115 (918) 835-1089 phone (918) 835-1754 fax www.barrettprecisionengines.com "Visit us at Airventure 2006, Bldg. C, Booth 3025" DO NOT ARCHIVE -----Original Message----- [mailto:owner-engines-list-server@matronics.com] On Behalf Of Gary Casey Sent: Wednesday, June 28, 2006 8:20 AM --> Engines-List message posted by: Gary Casey I forgot to mention - one characteristic of this setup is that when going LOP at 10% less fuel flow than at peak the EGT's will drop less than 50 degrees(F) before they start going up again. At that time the engine is obviously on the ragged edge and will start to run very rough, occasionally even back-firing. I haven't seen - or haven't noticed - this upward EGT trend and such a sharp lean limit on other engines. Is it because of the higher compression? Should I worry? Gary Casey On Jun 28, 2006, at 5:57 AM, Gary Casey wrote: > I have a IO-540 parallel-valve with 10:1 compression, a single > Slick mag and one Lightspeed ignition. I now have about 5 flight > hours on the engine. The engine was set up with 25 degrees timing > on both ignitions, but I was worried about peak cylinder pressures > and retarded the mag to about 21.5 degrees. Runups are a problem > in that there is a slight drop going to the electronic ignition (I > expected that), but a drop of maybe 300 rpm from 1700 on the mag > and running on the mag almost always misfires until I run lean for > several seconds to dry out the plugs. The misfire situation is > getting better, I assume because the engine is breaking in and > using less oil and partly because I'm doing less ground running > than before. I'm wondering if the large mag drop is normal, > possibly because the Lightspeed is giving quite a bit of advance > during runup because of the low manifold pressure (I forgot to read > the MAP during runup). Doe anyone know what the advance "curve" > looks like for the Lightspeed? I understand others have asked for > an official answer and it was supposedly "proprietary", but I also > understand you can get a readout from Lightspeed that gives the > actual advance. All one would have to do is plot the displayed > number against rpm and MAP to extract the algorithm. Anyone done > that? If I wanted to reduce the advance on the Lightspeed by maybe > 5 degrees is there a simple way to do that? I don't have any > travel in that direction on the pickup plate and I don't want to > retard the cranking advance. > > Gary Casey ________________________________ Message 8 _____________________________________ Time: 07:36:59 AM PST US From: "Tracy Crook" Subject: Re: Engines-List: Single electronic ignition Don't blame you for wanting to know as much as you can about your aircraft systems and hope this does not come off as condescending. Having said that, I would encourage you to follow the manufacturers' recommendation on setting up the system. I make EFI/Ignition engine controllers (for auto engine conversions) and the algorithms for ignition timing can be devilishly difficult to describe in a reasonable amount of time. There are so many if, ands, or buts that only a spreadsheet can accurately illustrate the timing. It's not a simple curve, at least not in a sophisticated ignition system. Don't take this as an indication that I know anything about the Lightspeed system, I don't. But I have had several builders come close to damaging their engines by trying to second guess what my controllers are doing. If you are going to entrust your machine to a manufacturer's widget, you might as well follow the instructions. I (and Lightspeed) ought to provide the spreadsheet that illustrates the timing curve and I intend to do that as soon as I find the time. The number of different engines that I make controllers for has grown to around 20 (timing is different on all of them) so it won't be easy. Tracy Crook ----- Original Message ----- From: Gary Casey To: engines-list@matronics.com Sent: Wednesday, June 28, 2006 8:57 AM Subject: Engines-List: Single electronic ignition --> Engines-List message posted by: Gary Casey > I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag and one Lightspeed ignition. I now have about 5 flight hours on the engine. The engine was set up with 25 degrees timing on both ignitions, but I was worried about peak cylinder pressures and retarded the mag to about 21.5 degrees. Runups are a problem in that there is a slight drop going to the electronic ignition (I expected that), but a drop of maybe 300 rpm from 1700 on the mag and running on the mag almost always misfires until I run lean for several seconds to dry out the plugs. The misfire situation is getting better, I assume because the engine is breaking in and using less oil and partly because I'm doing less ground running than before. I'm wondering if the large mag drop is normal, possibly because the Lightspeed is giving quite a bit of advance during runup because of the low manifold pressure (I forgot to read the MAP during runup). Doe anyone know what the advance "curve" looks like for the Lightspeed? I understand others have asked for an official answer and it was supposedly "proprietary", but I also understand you can get a readout from Lightspeed that gives the actual advance. All one would have to do is plot the displayed number against rpm and MAP to extract the algorithm. Anyone done that? If I wanted to reduce the advance on the Lightspeed by maybe 5 degrees is there a simple way to do that? I don't have any travel in that direction on the pickup plate and I don't want to retard the cranking advance. Gary Casey ========================= ========== http://www.matronics.com/Navigator?Engines-List ========================= ========== ========================= ========== http://www.matronics.com/contribution ========================= ========== ________________________________ Message 9 _____________________________________ Time: 08:22:38 AM PST US From: "Craig Berland" Subject: Engines-List: Re: Single electronic ignition --> Engines-List message posted by: "Craig Berland" Gary, I suspect that the mag is misfiring as you lean causing the burn time to increase and therefore the exhaust temps to climb as you continue to lean rather than the expected further temp decrease. I would be more inclined to set both ignitions at 22 or 23 deg BTDC. By setting the mag retarded it must fire against a slightly higher combustion chamber pressure due to the electronic ign has already fired and the pressure is rising. The mag is already being challenged by the 10 to 1 CR and LOP operation. Craig Berland I forgot to mention - one characteristic of this setup is that when going LOP at 10% less fuel flow than at peak the EGT's will drop less than 50 degrees(F) before they start going up again. At that time the engine is obviously on the ragged edge and will start to run very rough, occasionally even back-firing. I haven't seen - or haven't noticed - this upward EGT trend and such a sharp lean limit on other engines. Is it because of the higher compression? Should I worry? Gary Casey On Jun 28, 2006, at 5:57 AM, Gary Casey wrote: > I have a IO-540 parallel-valve with 10:1 compression, a single Slick > mag and one Lightspeed ignition. I now have about 5 flight hours on > the engine. The engine was set up with 25 degrees timing on both > ignitions, but I was worried about peak cylinder pressures and > retarded the mag to about 21.5 degrees. Runups are a problem in that > there is a slight drop going to the electronic ignition (I expected > that), but a drop of maybe 300 rpm from 1700 on the mag and running on > the mag almost always misfires until I run lean for several seconds to > dry out the plugs. The misfire situation is getting better, I assume > because the engine is breaking in and using less oil and partly > because I'm doing less ground running than before. I'm wondering if > the large mag drop is normal, possibly because the Lightspeed is > giving quite a bit of advance during runup because of the low manifold > pressure (I forgot to read the MAP during runup). Doe anyone know > what the advance "curve" > looks like for the Lightspeed? I understand others have asked for an > official answer and it was supposedly "proprietary", but I also > understand you can get a readout from Lightspeed that gives the actual > advance. All one would have to do is plot the displayed number > against rpm and MAP to extract the algorithm. Anyone done that? If I > wanted to reduce the advance on the Lightspeed by maybe > 5 degrees is there a simple way to do that? I don't have any travel > in that direction on the pickup plate and I don't want to retard the > cranking advance. > > Gary Casey ________________________________ Message 10 ____________________________________ Time: 10:52:43 AM PST US From: "steve korney" Subject: RE: Engines-List: Single electronic ignition --> Engines-List message posted by: "steve korney" Gary... One malfunction in the MAP sensor, and your engine could be toasted... I recommend you run the slick mag at 23 degrees for the 10:1 compression... Your light speed could be as much as 40 degrees at run-up... No wonder there is such a difference in drop-off in rpm's... Best... Steve ----Original Message Follows---- --> Engines-List message posted by: Gary Casey I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag and one Lightspeed ignition. I now have about 5 flight hours on the engine. The engine was set up with 25 degrees timing on both ignitions, but I was worried about peak cylinder pressures and retarded the mag to about 21.5 degrees. Runups are a problem in that there is a slight drop going to the electronic ignition (I expected that), but a drop of maybe 300 rpm from 1700 on the mag and running on the mag almost always misfires until I run lean for several seconds to dry out the plugs. The misfire situation is getting better, I assume because the engine is breaking in and using less oil and partly because I'm doing less ground running than before. I'm wondering if the large mag drop is normal, possibly because the Lightspeed is giving quite a bit of advance during runup because of the low manifold pressure (I forgot to read the MAP during runup). Doe anyone know what the advance "curve" looks like for the Lightspeed? I understand others have asked for an official answer and it was supposedly "proprietary", but I also understand you can get a readout from Lightspeed that gives the actual advance. All one would have to do is plot the displayed number against rpm and MAP to extract the algorithm. Anyone done that? If I wanted to reduce the advance on the Lightspeed by maybe 5 degrees is there a simple way to do that? I don't have any travel in that direction on the pickup plate and I don't want to retard the cranking advance. Gary Casey http://www.matronics.com/Navigator?Engines-List http://wiki.matronics.com ________________________________ Message 11 ____________________________________ Time: 10:55:23 AM PST US From: "steve korney" Subject: RE: Engines-List: Re: Single electronic ignition --> Engines-List message posted by: "steve korney" If your going to run your engine lean of peak at high altitude, you should have two electronic ignitions... Best... Steve ----Original Message Follows---- --> Engines-List message posted by: Gary Casey I forgot to mention - one characteristic of this setup is that when going LOP at 10% less fuel flow than at peak the EGT's will drop less than 50 degrees(F) before they start going up again. At that time the engine is obviously on the ragged edge and will start to run very rough, occasionally even back-firing. I haven't seen - or haven't noticed - this upward EGT trend and such a sharp lean limit on other engines. Is it because of the higher compression? Should I worry? Gary Casey On Jun 28, 2006, at 5:57 AM, Gary Casey wrote: >I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag >and one Lightspeed ignition. I now have about 5 flight hours on the >engine. The engine was set up with 25 degrees timing on both ignitions, >but I was worried about peak cylinder pressures and retarded the mag to >about 21.5 degrees. Runups are a problem in that there is a slight drop >going to the electronic ignition (I expected that), but a drop of maybe >300 rpm from 1700 on the mag and running on the mag almost always misfires >until I run lean for several seconds to dry out the plugs. The misfire >situation is getting better, I assume because the engine is breaking in >and using less oil and partly because I'm doing less ground running than >before. I'm wondering if the large mag drop is normal, possibly because >the Lightspeed is giving quite a bit of advance during runup because of >the low manifold pressure (I forgot to read the MAP during runup). Doe >anyone know what the advance "curve" looks like for the Lightspeed? I >understand others have asked for an official answer and it was supposedly >"proprietary", but I also understand you can get a readout from Lightspeed >that gives the actual advance. All one would have to do is plot the >displayed number against rpm and MAP to extract the algorithm. Anyone >done that? If I wanted to reduce the advance on the Lightspeed by maybe >5 degrees is there a simple way to do that? I don't have any travel in >that direction on the pickup plate and I don't want to retard the cranking >advance. > >Gary Casey http://www.matronics.com/Navigator?Engines-List http://wiki.matronics.com ________________________________ Message 12 ____________________________________ Time: 11:07:12 AM PST US From: "steve korney" Subject: RE: Engines-List: Re: Single electronic ignition --> Engines-List message posted by: "steve korney" Craig... You are right about...... "I would be more inclined to set both ignitions at 22 or 23 deg BTDC. By setting the mag retarded it must fire against a slightly higher combustion chamber pressure due to the electronic ign has already fired and the pressure is rising. The mag is already being challenged by the 10 to 1 CR and LOP operation." But, that doesn't happen on run-up... The EI is turned off... Best... Steve ----Original Message Follows---- --> Engines-List message posted by: "Craig Berland" Gary, I suspect that the mag is misfiring as you lean causing the burn time to increase and therefore the exhaust temps to climb as you continue to lean rather than the expected further temp decrease. I would be more inclined to set both ignitions at 22 or 23 deg BTDC. By setting the mag retarded it must fire against a slightly higher combustion chamber pressure due to the electronic ign has already fired and the pressure is rising. The mag is already being challenged by the 10 to 1 CR and LOP operation. Craig Berland I forgot to mention - one characteristic of this setup is that when going LOP at 10% less fuel flow than at peak the EGT's will drop less than 50 degrees(F) before they start going up again. At that time the engine is obviously on the ragged edge and will start to run very rough, occasionally even back-firing. I haven't seen - or haven't noticed - this upward EGT trend and such a sharp lean limit on other engines. Is it because of the higher compression? Should I worry? Gary Casey On Jun 28, 2006, at 5:57 AM, Gary Casey wrote: > I have a IO-540 parallel-valve with 10:1 compression, a single Slick > mag and one Lightspeed ignition. I now have about 5 flight hours on > the engine. The engine was set up with 25 degrees timing on both > ignitions, but I was worried about peak cylinder pressures and > retarded the mag to about 21.5 degrees. Runups are a problem in that > there is a slight drop going to the electronic ignition (I expected > that), but a drop of maybe 300 rpm from 1700 on the mag and running on > the mag almost always misfires until I run lean for several seconds to > dry out the plugs. The misfire situation is getting better, I assume > because the engine is breaking in and using less oil and partly > because I'm doing less ground running than before. I'm wondering if > the large mag drop is normal, possibly because the Lightspeed is > giving quite a bit of advance during runup because of the low manifold > pressure (I forgot to read the MAP during runup). Doe anyone know > what the advance "curve" > looks like for the Lightspeed? I understand others have asked for an > official answer and it was supposedly "proprietary", but I also > understand you can get a readout from Lightspeed that gives the actual > advance. All one would have to do is plot the displayed number > against rpm and MAP to extract the algorithm. Anyone done that? If I > wanted to reduce the advance on the Lightspeed by maybe > 5 degrees is there a simple way to do that? I don't have any travel > in that direction on the pickup plate and I don't want to retard the > cranking advance. > > Gary Casey ________________________________ Message 13 ____________________________________ Time: 01:05:14 PM PST US From: "J. R. Dial" Subject: RE: Engines-List: Single electronic ignition --> Engines-List message posted by: "J. R. Dial" My engine is an XP-360 and I always taxi and idle on the ground with the mixture at almost idle cut off. It won't hurt your engine and the plugs will stay clean. I am flying 200 hours a year and the plugs are clean when I pull them once a year. I have the same set up you have but my mag is set at factory setting of 25 degrees. I have great performance with the Lightspeed system and I received excellent customer service on some initial questions to Klaus. I get no drop during run up on the Lightspeed and about 50 RPM on the mag. Good luck -----Original Message----- [mailto:owner-engines-list-server@matronics.com] On Behalf Of Gary Casey Sent: Wednesday, June 28, 2006 7:58 AM --> Engines-List message posted by: Gary Casey I have a IO-540 parallel-valve with 10:1 compression, a single Slick mag and one Lightspeed ignition. I now have about 5 flight hours on the engine. The engine was set up with 25 degrees timing on both ignitions, but I was worried about peak cylinder pressures and retarded the mag to about 21.5 degrees. Runups are a problem in that there is a slight drop going to the electronic ignition (I expected that), but a drop of maybe 300 rpm from 1700 on the mag and running on the mag almost always misfires until I run lean for several seconds to dry out the plugs. The misfire situation is getting better, I assume because the engine is breaking in and using less oil and partly because I'm doing less ground running than before. I'm wondering if the large mag drop is normal, possibly because the Lightspeed is giving quite a bit of advance during runup because of the low manifold pressure (I forgot to read the MAP during runup). Doe anyone know what the advance "curve" looks like for the Lightspeed? I understand others have asked for an official answer and it was supposedly "proprietary", but I also understand you can get a readout from Lightspeed that gives the actual advance. All one would have to do is plot the displayed number against rpm and MAP to extract the algorithm. Anyone done that? If I wanted to reduce the advance on the Lightspeed by maybe 5 degrees is there a simple way to do that? I don't have any travel in that direction on the pickup plate and I don't want to retard the cranking advance. Gary Casey