I have heard a 'possible' way to get rid of that excessive carbon buildup in your engine. This, of course, is a very lowbuck solution...! I've never tried this myself yet, but you can 'trickle' some drops of water in your carb with the engine at 2500 rpm or higher. This 'boils' the carbon out of the cylinders somewhat. Care must be taken not to put too much water in at a time because of the danger of a waterlock, but you must be very generous with water if you're able to fill up a 90 cc head-chamber with water at 2500 rpm... Has anyone done this before, so you can clarify if this works as they say it does? Of course the only proper way to remove the carbon is to pull the heads. My '62 NewYorker Wagon 413 also pings when the engine is hot... And we even have 98 octane pumpfuel here...! Blocking the heat-crossover passage in the intake manifold does help a lot against pinging. I neglected this when I had the engine apart the last time. And it started pinging after that.. :o( Herman. The Netherlands http://drive.to/chrysler Hemi's Mopar and Dragracing Message Board: http://www.hostboard.com/cgi-bin/forumdisplay.cgi?action=topics&forum=Dutch+Dragracing+and+Mopar+Forum&number=318&DaysPrune=100&LastLogin= Magik Draggin' wrote: > The problem may not be timing related at all, but rather the result of > > carbon deposits on the cylinder ledges that remain hot after > compression and > ignition from the previous stroke and then ignite the incoming fuel > for the > next stroke prematurely. > > Short of pulling the heads and removing the deposits, you might simply > > consider retarding the timing to 5 deg BTDC (which is where the ram > engines > are set). Simply could be that 10 degrees of advance on a 40 yr old > 413 is > too much to compensate for even with hi-octane fuel. > > Karl > > > > >From: "Jennifer Allyn" <gearhead.girl@xxxx> > >To: "Chrysler 300 Club Int'l Listserver" > <chrysler300@xxxxxxxxxxxxxxx> > >Subject: [Chrysler300] Pinging & Timing > >Date: Sun, 16 Sep 2001 23:24:39 -0700 > > > >My 1962 413 (single 4-barrell) is making some good pinging these > days. > >I've > >checked the timing, which I have set at the 10-degree mark on the > balancer > >(as opposed to the 0-degree mark). Under the distributor cap I have > one of > >those electronic ignition boxes opposed to points. I run the > >highest-octane > >gas I can find. Not running any hotter than it usually does. > > > >Any ideas how to make the detonating cease? > > > >Thanks > >