---------------------------------------------------------- LycomingEngines-List Digest Archive --- Total Messages Posted Tue 12/15/09: 2 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:16 PM - Re: IO 360-A2A cylinder stud care (racerjerry) 2. 05:33 PM - Re: Adjusting spark plug gap (racerjerry) ________________________________ Message 1 _____________________________________ Time: 04:16:20 PM PST US Subject: LycomingEngines-List: Re: IO 360-A2A cylinder stud care From: "racerjerry" GOOD GAWD Please dont ever chase male threads with a die on anything that has a remote possibility of getting off the ground. Most all engine studs and aircraft hardware (and lately even common hardware store hardware) have rolled threads which significantly increases their resistance to fatigue. If a threading die is used to clean male threads, a small amount of metal will be removed at the thread root, causing stress risers in the bolts at their weakest (narrowest) point. [b][/b] Read this topic online here: http://forums.matronics.com/viewtopic.php?p=277664#277664 ________________________________ Message 2 _____________________________________ Time: 05:33:03 PM PST US Subject: LycomingEngines-List: Re: Adjusting spark plug gap From: "racerjerry" Aircraft Spruce now sells a tool to increase the gap of aircraft massive electrode spark plugs, but I definitely would not recommend it. Years ago I made one in a lathe from 3/8 diameter 4130 rod by drilling a center hole (about 0.150) so that the center electrode would pass through and tapering the end about 30 degrees to a sharp point. The pointed tip was heated to red and immersed in oil to harden it. I RARELY used this tool, because slight sideways pressure on the center electrode could easily crack the spark plug insulator, rendering the spark plug useless. For Lycoming engines, Lycoming Service Instruction 1042Y (or later) governs approved spark plugs. In SI 1042Y, it also states that Spark plug gage must be set at .016-.022 inch. If your gaps are no tighter than .015, you have nothing to worry about and the gap will soon self correct with use. At this point I am a whole lot more careful about squeezing the electrodes closed when using my gap adjuster tool (also homemade) and have not been tempted to use the gap enlarger tool in a very long time. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=277674#277674 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message lycomingengines-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/LycomingEngines-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/lycomingengines-list Browse Digests http://www.matronics.com/digest/lycomingengines-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.