---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Thu 07/09/09: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:12 AM - Re: Compression (Noel) 2. 04:52 PM - Re: Compression (Roger Lee) ________________________________ Message 1 _____________________________________ Time: 09:12:43 AM PST US From: "Noel" Subject: RE: JabiruEngine-List: Compression I=99ve tried dynamic tests over the years and found them to be more lying than a politician on the campaign trail. Also when they do actually find a low cylinder you still have the problem of finding where compression is lost. Noel From: owner-jabiruengine-list-server@matronics.com [mailto:owner-jabiruengine-list-server@matronics.com] On Behalf Of T. Graziano Sent: 07 July 2009 17:23 Subject: Re: JabiruEngine-List: Compression Bobby, Have you tried "dynamic"compression testing (see compression testing Page 18 of Jab Instruction & Maintenance Manual, Rev 3 dated 18 Jul 2008. (this is for the solid lifter 3300A - suspect the hydraulic lifter is the same) Para 5.7.8 "Compression Testing: Condition of compression can be done by a compression gauge. Wide open throttle, engine warm. Turn over on starter. Below 90 psi would indicate removal of head and possibly cylinder> At my last annual, almost a year ago, I read 160#, 160#, 160#, 165#, 165 and 170# on my Jab with 408 hrs. Not much, if any, change from the years before. Tony Graziano ZodiacXL/Jab3300A - Ser 33A644; N493TG; 509 hrs. ----- Original Message ----- From: BobbyPaulk@COMCAST.NET Sent: Tuesday, July 07, 2009 10:30 AM Subject: JabiruEngine-List: Compression all, i have just taken differential compression test on my 3300A with 84 hrs S.N. 1141.( Conditional Inspection ) No. 2 and 6 had 75 & 77 the rest had low to mid 60's. i could rock the prop to seat the rings and get another 5 ~ 6 lbs. while on #5 near the oil collector bottle i could feel air out the bottle vent so the air is going thru the rings and pressurizing the crankcase. Test was on a cold engine setting up for about 2 weeks. my question is at 84 hrs could this many cylinders have rings not yet seated. last year all were in the high 70's. the engine starts fine as always and i have not noticed any power drop. the first 40 hrs or so the engine ran too lean and it was difficult to control high EGT / CHT's. any ideas?? Bobby 601 XL href="http://www.matronics.com/Navigator?JabiruEngine-List">http://www. matronics.com/Navigator?JabiruEngine-List href="http://forums.matronics.com">http://forums.matronics.com href="http://www.matronics.com/contribution">http://www.matronics.com/c ________________________________ Message 2 _____________________________________ Time: 04:52:32 PM PST US Subject: JabiruEngine-List: Re: Compression From: "Roger Lee" Hi Guys, Are you making sure to test with an engine up at operating temps. Shouldn't be cold. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Service Center 520-574-1080 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=252386#252386 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message jabiruengine-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/JabiruEngine-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/jabiruengine-list Browse Digests http://www.matronics.com/digest/jabiruengine-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.