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Jim, I gotta disagree with you on this detonation topic. It can happen at higher RPM -- I've experienced it around 2600-3000rpm while trying to make it up a hill. Higher compression engines, like my engine, that are at operating temp or higher can have preignition and detonation events occur, particularly while the engine is under load (driving up a hill or that damn mountain in Arizona y'all are gabbing about) and too much gas is being delivered (heavy throttle). You will notice that backing off on the throttle stops this condition. Retarding the spark advance will help as well but you may experience a loss in acceleration and power. Jacobs Electronics has a dash mounted module that allows one to adjust their timing on the fly (i.e. while driving) -- very neat idea! For those who don't know what detonation, or "pinging" as some refer to it, is when the air-fuel mixture suddenly explodes in the combustion chamber instead of burning. Sounds kind of funny, but the mixture normally gets used up in a smoothly expanding burn. Detonation is the gas exploding, expanding *very* rapidly and putting a LOT of stress on the pistons, rods and bearings. If you don't know what it sounds like I'll give you the great example Jim gave me a while back: It sounds like there are a bunch of BB's or metal nuts rattling around in your engine. Toby Erkson air_cooled_nut@pobox.com <-- Please use this address for email '72 VW Squareback 1.6L bored and stroked to 2.0L, Berg five-speed '75 Porsche 914 1.8L, ORPCA member Portland, Oregon, http://www.pobox.com/~toby_erkson/ >-----Original Message----- > >Roasting yourself alive is pointless. Detonation is a low RPM >phenomenum, even more common in a cold engine where the mixture is >denser. ------------------------------------------------------------------- Too much? Digest! mailto:type3-d-request@vwtype3.org Subj=subscribe