Chuck, I agree, the big end bearing might have dropped a couple of rollers. Your engine theory is a little rusty though.... It fires the spark @ 20 to 30 degrees roughly BTDC, but the motor ignites @ TDC or after. If it fired BTDC, it would ping and or detonate. Somethine else to think of, a serious pre-ignition, could cause a rod bearing failure, so that might be an end result CR
Chuck Voboril <[EMAIL PROTECTED]> wrote: John, The broken rod theory only fits up to a point. Ker-thunk on rotation and smashed electrode are pretty good smoking guns..but. The less than adrupt stoppage with oddball sound prior to losing that one cylinder seems out of line with a broken rod. But maybe it still isn't broken completely in half or didn't break all at once. If only part of the rod big end opened up and the piston started kissing the plug more and more that might explain the odd noises before loss of that cylinder. Since actual ignition firing is well before TDC, a mechanical "kiss" would be spaced after a firing. Chuck >From: "John Vriesinga" >Reply-To: [email protected] >To: >Subject: Re: [F500] Help I don't know what to do anymore >Date: Sun, 24 Sep 2006 22:35:24 -0400 > >>Faulty electronics also doesn't appear to explain why you melted one >>electrode and the other is perfect, or is it? > >Both plugs looked beautiful prior to the last run. I noticed that the >engine started to sound ratty, like it was firing more often than it was >supposed to. There was the steady drone of the usual firing but in between >there was a ragged sounding firing tha sounded like it was limited to one >cylinder. Then it suddenly took to firing on one cylinder only ( when the >electrodes fused toegether I imagine) and finally it shut down completely. > >>What is your timing set at? At least tell us where you are in the stator >>slots. If the stator is rotated as far as it wil go CCW that is max >>advance. Estimate the gap to the end of the CCW travel.(looking from mag >>end of motor.) >> >>Then, what is your jetting? Fuel you are using? > >Using Sunoco 94 through 2 36mm Mikuni with 240 jets. > >>Dual port fuel pump with a very weak or intermittent output to one >>cylinder? > >I've got the regular old mechanical pump on. I disconnected the electric a >while ago thinking that it might be overfilling the carbs. > >>Now that might possibly be temperature dependent. > >>Crankcase pulse pump giving up when motor is hot and more fuel always left >>in one bowl then other. Then cornering force takes that low fuel level >>cylinder totally lean first? >>-kinda reaching here :-> > >Sounds to me like it's time for a completely new engine. > >JV --------------------------------- Stay in the know. Pulse on the new Yahoo.com. Check it out. ________________________________ FormulaCar Magazine - A Proud Supporter of Formula 500 The Official Publication of Junior Formula Car Racing Subscribe Today! www.formulacarmag.com or 519-624-2003 _________________________________ _______________________________________________ F500 mailing list - [email protected] To unsubscribe or change options please visit: http://f500.org/mailman/listinfo/f500 *** Please, DO NOT send unsubscribe requests to the mailing list! ***
