Chris, You are correct. Unless Ken messed with the timing, my guess is that it is just a lean situation.
Also, I did forget to mention the "clean the crankcase" thing. I was getting a little long in my note and left that off, but it is important. I don't have a "stack" of melted pistons, just 6 or 7 of them. Most of them from the Kawasaki, one from the 494. Guess I am a slow learner. You would think that after a couple, I would get the idea, to lean, to bad ! All caused by lean conditions, for some reason or another. Richard ----- Original Message ----- From: "Chris Reinhardt" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, August 27, 2006 4:56 PM Subject: Re: [F500] Melted 494 piston question > Richard I would clarify that a little bit. The top of the piston and plug deposists are dead givaways for DETONATION!!!! Usually timming, but could be a lean deto. A temp related sieze you would see the tell tale "4 Corner" stick meaning the piston expanded evenly all the way around. Lack of lube, will generally give a score on both skirts, along with blue'd wrist pin bearing. A lean sieze is usually a melt on the top of the piston closest to the exhuast port. > Warning!!!! A bunch of that aluminum that used to be a piston, is now in the crankcase. I would not even think of just cleaning up the jug and stuffing a piston in it unless I had a race that day, otherwise flush the crankcase best you can. > > CR > PS I have a stack of 125 pistons with every type sieze you could imagine!!! > > Richard Schmidt <[EMAIL PROTECTED]> wrote: > Ken, > > I doubt that your piston melt down has to do with high water temp. Aluminum > deposits on the spark plug is a sign of a melted piston. Most likely caused > by too lean a fuel mixture to that cylinder. Lack of proper lubrication > could also cause a piston to seize, but this would not cause the top of the > piston to melt. > > A lean running engine will run hotter and put more energy into the coolant, > but this an effect, not the cause. > > Do not attempt to rotate your engine any more than you have. This could > cause more damage. The fix is to disassemble the top end of the engine and > remove the affected cylinder and piston. Carefully inspect the other > cylinder walls and piston for damage. It may not be necessary to remove the > other cylinder if no damage can be seen to the piston and cylinder walls. > > You can easily remove the aluminum welded to the cylinder wall using common > hydrochloric acid used for pool maintenance. Be sure to do this outdoors > and wear a good pair of rubber gloves. Make sure you are up-wind from the > cylinder and just pore a little at a time in the cylinder. You will get a > lot of bubbling action. Carefully rinse the cylinder with water and examine > it. Use a steel bristle brush to remove any oxidation. If some aluminum > still remains, repeat. The acid will not harm the steel liner. Be careful > not to get the acid on the other aluminum parts of the cylinder. > > When all the aluminum is gone, inspect the cylinder for scoring. If you > broke a ring, you may have scoring. Depending on how bad it is, you may just > be able to use a hone on the cylinder to remove some of the scoring and get > a cross hatch pattern again. > > Get a new piston and rings and reassemble. Piece of cake ! > > As for the fastest way to get going again, replace the engine, most likely > no more that two hours of work. Of course you have to have a standby engine. > If possible, never go to the track without a backup engine. It may seem > like an extra expense, but if you add up all the expenses of just getting to > the track and entry fees, you will soon realize that you will actually save > money if you have a back up engine to run on Sunday rather than go home. > > Richard > > > > ----- Original Message ----- > From: "Kenneth Kirkland" > To: > Sent: Saturday, August 26, 2006 10:32 PM > Subject: [F500] Melted 494 piston question > > > > Hello all!!! > > > > I'm an F5 newbie running my first season of regionals > > in the Midwest Division. I've been lurking on the list > > for a while but haven't had a question to pose yet. My > > first is a doozy. > > > > Apparently, a piston in my 494 melted down due to high > > water temps during a regional at Hallett on 8/6/06. > > There are some wonderfully shiny metallic deposits on > > the spark plug in the left cylinder. The crank will > > only turn about 45 degrees, with some metal on metal > > sounds accompanying what little rotation there is. > > > > I had hoped to run one more regional before the end of > > the year to get a national license when I renew my > > license in early '07. What's the best approach to > > remedy this situation? Redo the top end? Bolt in an > > entire rebuilt engine? What symptoms would dictate the > > need to work on the bottom end? > > > > > > Thanks for any and all assistance, > > Kenneth Kirkland > > MiDiv #18 > > www.kirklandracing.com ________________________________ 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! ***
