lml@lancaironline.net Mailing List Archive

<<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> Some time ago (Sept 2000), Jim Frantz described his problems with the shut-down of some instrumentation when the bus voltage dropped temporarily below 10 volts due to the high current draw of the starter - lightweight starters in particular . I have just experienced a similar, related problem. The bottom line - when I got there finally - was that the combined series resistance of the master relay and starter relay were dropping the voltage ACROSS THE STARTER to less than 10volts during cranking. With the result that the Skytec could not drive the engine over TDC - the swing-back (not fire-back) was painful - especially for the starter drive assembly and the engine ring gear! Now I know why the Sky-Tec manual says they will not answer any warrantee questions when this voltage is less than 10volts! The manual also says that if the starter cable run is more than 2 metres the cable should be No.2 at least. I believe it! But since this is close to what is required by the lay-out of the Lancair 320, and my cable is No.4., since I built originally for Lycoming's own lightweight starter and only had it replaced later (free by Lycoming, when it's casting broke). The option of increasing the cable size is a bitch to even contemplate. And apparently everything is OK as long as both relays are new and up to spec.. So my questions to the group;- a) anyone else experienced to this problem? b) are there better master and starter relay out there? (e.g Bosch - I read all old mails about replacement for the hydraulics relays, but that's for significantly less current) c) is the solution just regular replacement of these relays? (I took apart the old master relay and the contacts are dirty and not a pretty sight. But who knows how that affects there attitude to a zap of +100amps ?). Any help? Colin Jones (PH-COL @ EHLE) LML website: http://members.olsusa.com/mkaye/maillist.html LML Builders' Bookstore: http://www.buildersbooks.com/lancair Please remember that purchases from the Builders' Bookstore assist with the management of the LML. Please send your photos and drawings to marvkaye@olsusa.com.