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Author Topic:   Pre-detonattion
Dirt Full Roller

Total posts: 32
posted March 12, 2003 05:24 PM
What does this sound like?Am I a tooth off?I have checked all valvetrain and all good.I also think there is a possibility of a weak spring .

rico 08
Dirt Freak

Total posts: 372
posted March 13, 2003 01:32 PM
Predetonation is where the air mixture gets ignited before spark is produced/t.d.c.,this will really destroy an engine quick,the cylinder pressures generated are unreal,it's a lot more harmful than just spark knock,if you've ever overheated a motor to the point where it knocked under acceleration then you've heard it,if it does it when cold then i'd think you have another problem maybe bearings or maybe interference(like the weak spring you mentioned).

Dirt Full Roller

Total posts: 61
posted March 13, 2003 11:19 PM
too hot of a spark plug, too much timing, too low of an octane rating, improper quench area in the cylinder, hot spots in the cylinder (a burr on the piston or combustion chamber) will all cause detonation. This will destroy your engine really fast!! Did you degree your cam? try a colder plug, double check your timing advance and total timing and make sure you run the right octane fuel. Improper quench area (determined by how far down the piston sits and head gasket thickness) will affect this too. hope this helps.

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