---------------------------------------------------------- TeamGrumman-List Digest Archive --- Total Messages Posted Tue 10/27/09: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:59 AM - Re: horizontal braces (flyv35b) 2. 06:46 AM - Re: cranking pressure (flyv35b) 3. 11:19 AM - Re: cranking pressure (teamgrumman@aol.com) 4. 11:40 AM - Replacing rudder springs (teamgrumman@aol.com) 5. 01:34 PM - IMG00070-20091027-1034.jpg (Denham, Bobby D.) 6. 01:39 PM - IMG00064-20091025-0829.jpg (Denham, Bobby D.) 7. 06:35 PM - Re: cranking pressure (James Courtney) 8. 06:53 PM - Re: IMG00070-20091027-1034.jpg (James Courtney) 9. 07:54 PM - Re: cranking pressure (teamgrumman@AOL.COM) ________________________________ Message 1 _____________________________________ Time: 05:59:10 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: horizontal braces You are becoming the tail crack =22expert=22. If I run across any I'm going to send them down to you! Cliff ----- Original Message ----- From: teamgrumman@aol.com To: teamgrumman-list@matronics.com Sent: Monday, October 26, 2009 8:29 PM Subject: TeamGrumman-List: horizontal braces I delivered the plane Saturday with the new horizontal braces. One obser vation: it could be me but, I think the horizontal felt stiffer than even the one on my plane. Plane flew well. I did some steep turns and pulled a couple of g's. We'll see. I have 3 more planes with cracks. =5F-=========================================================== =5F-= - The TeamGrumman-List Email Forum - =5F-= Use the Matronics List Features Navigator to browse =5F-= the many List utilities such as List Un/Subscription, =5F-= Archive Search & Download, 7-Day Browse, Chat, FAQ, =5F-= Photoshare, and much much more: =5F- =5F-= --> http://www.matronics.com/Navigator=3FTeamGrumman-List =5F- =5F-=========================================================== =5F-= - MATRONICS WEB FORUMS - =5F-= Same great content also available via the Web Forums! =5F- =5F-= --> http://forums.matronics.com =5F- =5F-=========================================================== =5F-= - List Contribution Web Site - =5F-= Thank you for your generous support! =5F-= -Matt Dralle, List Admin. =5F-= --> http://www.matronics.com/contribution =5F-=========================================================== -- We are a community of 6 million users fighting spam. The Professional version does not have this message ________________________________ Message 2 _____________________________________ Time: 06:46:00 AM PST US From: "flyv35b" Subject: Re: TeamGrumman-List: cranking pressure I've have lots of other stuff to chew on but here is a thought without givi ng it much thought! You obviously are aware of dynamic compression ratio w hich is affected by valve timing and probably more significant that static CR. I would GUESS that something is different on the #3 cylinder valve tim ing like you mentioned. Short of a camshaft that is maybe not to spec I wo uld suspect that an intake lifter is bleeding down rapidly or the dry tappe t clearance is out of spec, resulting in an early intake valve closing, les s overlap, and therefore higher dynamic CR and cranking pressure. I would wonder if the difference you are seeing would result in a rough running eng ine. How smooth does it run=3F Also there could be other factors like the actual combustion chamber cleara nce volume and therefore static CR. On my Porsche engine a .010=22 change in piston deck height changes the static CR by 0.25 points. A small change i n combustion chamber volume changes it even more. I could imagine some man ufacturing variables with the cylinder which could at least partially accou nt for the difference in cranking pressure. Seems like the easiest thing t o check or try would be to check the dry tappet clearance on at least #3 an d #4 and swap the intake hydraulic lifters and retest the cranking pressure . That might tell you a lot. Having the tester that Bill Scott uses to te st the leakdown rate would be very informative possibly. BTW, I assume the cranking pressures you mentioned for Cheetahs is with the stock engine with 7.0:1 CR=3F Cliff ----- Original Message ----- From: teamgrumman@aol.com To: teamgrumman-list@matronics.com Sent: Monday, October 26, 2009 8:21 PM Subject: TeamGrumman-List: cranking pressure Cliff, here's one for you to chew on. I've been doing both leak down and cranking pressure tests now for about a year. Tigers generally run 130-135. One Lycon Tiger was 145 across the board. Cheetahs run about 125 to 130. I did a cranking pressure test on a Tiger last weekend with (1) 125 psi (2) 123 psi (3) 142 psi (4) 120 psi I redid the #3 4 times and got the same value. Something is changing the valve timing events enough to cause this difference. I didn't go any furt her into it. The leak down tests were 79/78/78/78 =5F-=========================================================== =5F-= - The TeamGrumman-List Email Forum - =5F-= Use the Matronics List Features Navigator to browse =5F-= the many List utilities such as List Un/Subscription, =5F-= Archive Search & Download, 7-Day Browse, Chat, FAQ, =5F-= Photoshare, and much much more: =5F- =5F-= --> http://www.matronics.com/Navigator=3FTeamGrumman-List =5F- =5F-=========================================================== =5F-= - MATRONICS WEB FORUMS - =5F-= Same great content also available via the Web Forums! =5F- =5F-= --> http://forums.matronics.com =5F- =5F-=========================================================== =5F-= - List Contribution Web Site - =5F-= Thank you for your generous support! =5F-= -Matt Dralle, List Admin. =5F-= --> http://www.matronics.com/contribution =5F-=========================================================== -- We are a community of 6 million users fighting spam. The Professional version does not have this message ________________________________ Message 3 _____________________________________ Time: 11:19:17 AM PST US Subject: Re: TeamGrumman-List: cranking pressure From: teamgrumman@aol.com Funny you should ask about the Cheetah compression ratio. I haven't seen a stock compression ratio Cheetah in years. Those values are for the HC pistons. This particular engine with the weird #3 cranking pressure had the #1 cyli nder replaced a few months ago by Pacific Air Care in Watsonville, CA. My thought is, the plane doesn't get much use and there is a good chance the lifters are all gummed up. I wish I had seen the plane to replace the cy linder. I'd know what shape the lifters were in. When James Courtney had a cylinder fail over San Francisco bay I had a cha nce to see the lifters before I put everything back together. They were carboned up to the point they did not collapse at all. We ended up doing a complete top end overhaul. The cylinders had about 1100 hours on them and I didn't trust that the other valves would fail. Besides, you know I recommend new cylinders at 1000 hours. Whatever is weird with the #3 it's either causing the cylinder not to scav enge the exhaust or the intake event is closing early. Either way, leak down didn't show anything. -----Original Message----- From: flyv35b Sent: Tue, Oct 27, 2009 6:22 am Subject: Re: TeamGrumman-List: cranking pressure I've have lots of other stuff to chew on but here is a thought without giving it much thought! You obviously are aware of dynami c compression ratio which is affected by valve timing and probably more significant that static CR. I would GUESS that something is different on the #3 cylinder valve timing like you mentioned. Short of a camshaft that is maybe not to spec I would suspect that an intake lifter is bleeding dow n rapidly or the dry tappet clearance is out of spec, resulting in an early intake valve closing, less overlap, and therefore higher dynamic CR and cranking pressure. I would wonder if the difference you are seeing would result in a rough running engine. How smooth does it run? Also there could be other factors like the actual combustion chamber clearance volume and therefore static CR. On my Porsch e engine a .010" change in piston deck height changes the static CR by 0.25 points. A small change in combustion chamber volume changes it even more. I could imagine some manufacturing variables with the cylinder whic h could at least partially account for the difference in cranking pressure. Seems like the easiest thing to check or try would be to check the dry tap pet clearance on at least #3 and #4 and swap the intake hydraulic lifters and retest the cranking pressure. That might tell you a lot. Having the tester that Bill Scott uses to test the leakdown rate would be very informative possibly. BTW, I assume the cranking pressures you mentioned for Cheetahs is with the stock engine with 7.0:1 CR? Cliff ----- Original Message ----- From: teamgrumman@aol.com Sent: Monday, October 26, 2009 8:21 PM Subject: TeamGrumman-List: cranking pressure Cliff, here's one for you to chew on. I've been doing both leak down and cranking pressure tests now for about a year. Tigers generally run 130-135. One Lycon Tiger was 145 across the board. Cheetahs run about 125 to 130. I did a cranking pressure test on a Tiger last weekend with (1) 125 psi (2) 123 psi (3) 142 psi (4) 120 psi I redid the #3 4 times and got the same value. Something is changing the valve timing events enough to cause this difference. I didn't go any further into it. The leak down tests were 79/78/78/78 ======================== =========== ======================== =========== ======================== =========== ======================== =========== We are a community of 6 million users fighting spam. SPAMfersion does not have this message. ======================== =========== ======================== =========== ======================== =========== ======================== =========== ________________________________ Message 4 _____________________________________ Time: 11:40:10 AM PST US Subject: TeamGrumman-List: Replacing rudder springs From: teamgrumman@aol.com I got an email from one of my customers who'd seen me replace rudder sprin gs regarding a post on the other site regarding rudder spring replacement. He sent the email too. Using nickels to spread the spring so you can install it? That's a joke, right? Forward this to the experts on GG (1) Get three two-foot rubber bungie cords, the thick rubber ones. (2) Remove the seats, hook the rubber bungie cord onto the top of one of the rudder peddles and stretch it back to the seat bracket and hook it th ere. Repeat with the other two bungie cords. NOTE: You find one spring stretched, the other will be loose with no load on it all all. (3) Get some vise grips and grab the loop on the end of the old rudder spr ing. Sometimes the firewall is easier to remove, sometimes the peddle sid e. Your choice. (4) Twist the loop out of the hole where it goes through (5) Remove the spring. (6) Get the new spring, hook it on the peddle side and stretch it enough to get it on the firewall attachment. It's really quite easy. Repeat with the other side. Both springs can be replaced from the co-pilo ts side without removing the pilots console cover. I've been doing it this way for 20 years. ________________________________ Message 5 _____________________________________ Time: 01:34:47 PM PST US Subject: TeamGrumman-List: IMG00070-20091027-1034.jpg From: "Denham, Bobby D." DQotLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLQ0KU2VudCB1c2luZyBCbGFja0JlcnJ5DQo ________________________________ Message 6 _____________________________________ Time: 01:39:31 PM PST US Subject: TeamGrumman-List: IMG00064-20091025-0829.jpg From: "Denham, Bobby D." DQotLS0tLS0tLS0tLS0tLS0tLS0tLS0tLS0tLQ0KU2VudCB1c2luZyBCbGFja0JlcnJ5DQo ________________________________ Message 7 _____________________________________ Time: 06:35:40 PM PST US From: "James Courtney" Subject: RE: TeamGrumman-List: cranking pressure I remember freeing the lifters with you at San Rafel to install the temporary cylinder from Lycon to ferry the plane to Auburn. It was sticky! Hopefully the new owner is enjoying a trouble-free engine. I still greatly appreciate your excellent customer care in coming down to San Rafel to get things straightened out! Jamey From: owner-teamgrumman-list-server@matronics.com [mailto:owner-teamgrumman-list-server@matronics.com] On Behalf Of teamgrumman@aol.com Sent: Tuesday, October 27, 2009 11:18 AM Subject: Re: TeamGrumman-List: cranking pressure Funny you should ask about the Cheetah compression ratio. I haven't seen a stock compression ratio Cheetah in years. Those values are for the HC pistons. This particular engine with the weird #3 cranking pressure had the #1 cylinder replaced a few months ago by Pacific Air Care in Watsonville, CA. My thought is, the plane doesn't get much use and there is a good chance the lifters are all gummed up. I wish I had seen the plane to replace the cylinder. I'd know what shape the lifters were in. When James Courtney had a cylinder fail over San Francisco bay I had a chance to see the lifters before I put everything back together. They were carboned up to the point they did not collapse at all. We ended up doing a complete top end overhaul. The cylinders had about 1100 hours on them and I didn't trust that the other valves would fail. Besides, you know I recommend new cylinders at 1000 hours. Whatever is weird with the #3 it's either causing the cylinder not to scavenge the exhaust or the intake event is closing early. Either way, leak down didn't show anything. -----Original Message----- From: flyv35b Sent: Tue, Oct 27, 2009 6:22 am Subject: Re: TeamGrumman-List: cranking pressure I've have lots of other stuff to chew on but here is a thought without giving it much thought! You obviously are aware of dynamic compression ratio which is affected by valve timing and probably more significant that static CR. I would GUESS that something is different on the #3 cylinder valve timing like you mentioned. Short of a camshaft that is maybe not to spec I would suspect that an intake lifter is bleeding down rapidly or the dry tappet clearance is out of spec, resulting in an early intake valve closing, less overlap, and therefore higher dynamic CR and cranking pressure. I would wonder if the difference you are seeing would result in a rough running engine. How smooth does it run? Also there could be other factors like the actual combustion chamber clearance volume and therefore static CR. On my Porsche engine a .010" change in piston deck height changes the static CR by 0.25 points. A small change in combustion chamber volume changes it even more. I could imagine some manufacturing variables with the cylinder which could at least partially account for the difference in cranking pressure. Seems like the easiest thing to check or try would be to check the dry tappet clearance on at least #3 and #4 and swap the intake hydraulic lifters and retest the cranking pressure. That might tell you a lot. Having the tester that Bill Scott uses to test the leakdown rate would be very informative possibly. BTW, I assume the cranking pressures you mentioned for Cheetahs is with the stock engine with 7.0:1 CR? Cliff ----- Original Message ----- From: teamgrumman@aol.com Sent: Monday, October 26, 2009 8:21 PM Subject: TeamGrumman-List: cranking pressure Cliff, here's one for you to chew on. I've been doing both leak down and cranking pressure tests now for about a year. Tigers generally run 130-135. One Lycon Tiger was 145 across the board. Cheetahs run about 125 to 130. I did a cranking pressure test on a Tiger last weekend with (1) 125 psi (2) 123 psi (3) 142 psi (4) 120 psi I redid the #3 4 times and got the same value. Something is changing the valve timing events enough to cause this difference. I didn't go any further into it. The leak down tests were 79/78/78/78 =================================== ator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List =================================== ttp://forums.matronics.com =================================== ibution">http://www.matronics.com/contribution =================================== _____ .. We are a community of 6 million users fighting spam. SPAMfersion does not have this message. =================================== ator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List =================================== ttp://forums.matronics.com =================================== ibution">http://www.matronics.com/contribution =================================== Checked by AVG - www.avg.com 07:38:00 ________________________________ Message 8 _____________________________________ Time: 06:53:33 PM PST US From: "James Courtney" Subject: RE: TeamGrumman-List: IMG00070-20091027-1034.jpg Flying a little low in that one? From: owner-teamgrumman-list-server@matronics.com [mailto:owner-teamgrumman-list-server@matronics.com] On Behalf Of Denham, Bobby D. Sent: Tuesday, October 27, 2009 1:32 PM Subject: TeamGrumman-List: IMG00070-20091027-1034.jpg -------------------------- Sent using BlackBerry Checked by AVG - www.avg.com 10/27/09 07:38:00 ________________________________ Message 9 _____________________________________ Time: 07:54:34 PM PST US Subject: Re: TeamGrumman-List: cranking pressure From: teamgrumman@AOL.COM Hi Jamey, The new owner, Dave, loves the plane. Every year he comes up here and doe s an owner assist. Gary -----Original Message----- From: James Courtney Sent: Tue, Oct 27, 2009 6:21 pm Subject: RE: TeamGrumman-List: cranking pressure I remember freeing the lifters with you at San Rafel to install the temporary cylinder from Lycon to ferry the plane to Auburn. It was sticky! Hopefully the new owner is enjoying a trouble-free engine. I sti ll greatly appreciate your excellent customer care in coming down to San Rafe l to get things straightened out! Jamey From: owner-teamgrumman-list-server@matronics.com [mailto:owner-teamgrumman-list-server@matronics.com] On Behalf Of teamgrum man@aol.com Sent: Tuesday, October 27, 2009 11:18 AM Subject: Re: TeamGrumman-List: cranking pressure Funny you should ask about the Cheetah compression ratio. I haven't seen a stock compression ratio Cheetah in years. Those values are for the HC pistons. This particular engine with the weird #3 cranking pressure had the #1 cylinder replaced a few months ago by Pacific Air Care in Watsonville, CA. My thought is, the plane doesn't get much use and there is a good chance the lifters are all gummed up. I wish I had seen the plane to replace the cylinder. I'd know what shape the lifters were in. When James Courtney had a cylinder fail over San Francisco bay I had a chance to see the lifters before I put everything back together. They were carboned up to the point they did not collapse at all. We ended up doing a complete top end overhaul. The cylinders had about 1100 hours on them and I didn't trust that the other valves would fail. Besides, you know I recommend new cylinders at 1000 hours. Whatever is weird with the #3 it's either causing the cylinder not to scavenge the exhaust or the intake event is closing early. Either way, leak down didn't show anything. -----Original Message----- From: flyv35b Sent: Tue, Oct 27, 2009 6:22 am Subject: Re: TeamGrumman-List: cranking pressure I've have lots of other stuff to chew on but here is a thought without giving it much thought! You obviously are aware of dynamic compression ratio which is affected by valve timing and probably more significant that static CR. I would GUESS that something is different on the #3 cylinder valve timing like you mentioned. Short of a camshaft that is maybe not to spec I would suspect that an intake lifter is bleeding dow n rapidly or the dry tappet clearance is out of spec, resulting in an early intake valve closing, less overlap, and therefore higher dynamic CR and cranking pressure. I would wonder if the difference you are seeing would result in a rough running engine. How smooth does it run? Also there could be other factors like the actual combustion chamber clearance volume and therefore static CR. On my Porsche engine a .010" change in piston deck height changes the static CR by 0.25 points. A small change in combustion chamber volume changes it even more. I could imagine some manufacturing variables with the cylinder which could at least partially account for the difference in cranking pressure. Seems like the easiest thing to check or try would be to check the dry tappet clearance on at least #3 and #4 and swap the intake hydraul ic lifters and retest the cranking pressure. That might tell you a lot. Having the tester that Bill Scott uses to test the leakdown rate would be very informative possibly. BTW, I assume the cranking pressures you mentioned for Cheetahs is with the stock engine with 7.0:1 CR? Cliff ----- Original Message ----- From: teamgrumman@aol.com Sent: Monday, October 26, 2009 8:21 PM Subject: TeamGrumman-List: cranking pressure Cliff, here's one for you to chew on. I've been doing both leak down and cranking pressure tests now for about a year. Tigers generally run 130-135. One Lycon Tiger was 145 across the board. Cheetahs run about 125 to 130. I did a cranking pressure test on a Tiger last weekend with (1) 125 psi (2) 123 psi (3) 142 psi (4) 120 psi I redid the #3 4 times and got the same value. Something is changing the valve timing events enough to cause this difference. I didn't go any further into it. The leak down tests were 79/78/78/78 ======================== =========== ator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List ======================== =========== ttp://forums.matronics.com ======================== =========== ibution">http://www.matronics.com/contribution ======================== =========== We are a community of 6 million users fighting spam. SPAMfersion does not have this message. ======================== =========== ator?TeamGrumman-List">http://www.matronics.com/Navigator?TeamGrumman-List ======================== =========== ttp://forums.matronics.com ======================== =========== ibution">http://www.matronics.com/contribution ======================== =========== http://www.matronics.com/Navigator?TeamGrumman-List http://forums.matronics.com http://www.matronics.com/contribution No virus found in this incoming message. Checked by AVG - www.avg.com 10/27/09 07:38:00 ======================== =========== ======================== =========== ======================== =========== ======================== =========== ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message teamgrumman-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/TeamGrumman-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/teamgrumman-list Browse Digests http://www.matronics.com/digest/teamgrumman-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.