I need some advice on the color of the plugs from my road engine. The engine is a std 302 Windsor from an Aussie 90's AU series Ford Falcon with Motec M800 and 4 barrel fuel injection. Also 4 into 1 exhaust with cats and no crossover. The fuel map is an emission map to get the car registered, so is not perfect, but I don't understand why the plugs from the end cylinders (1,4,5,8) are blacker than the middle cylinders. The individual cylinder trims are within ~6% of each other (up to 3000RPM and no differences after that) and don't correlate with the color of the plugs. Is this a sign of different temperatures between cylinders and is this a normal state of affairs for the Windsor V8? Or is this a sign of a cooling problem? The only other change to the engine is a valve in the water line from the rear of the inlet manifold. This was put in after reading posts on this forum a couple of months ago. However, this valve may not do much as the engine is not tilted like most because the engine mounts have been lowered and moved forwards. I have found though that having this valve wide open lowers the engine temp by ~5 degrees Celsius. Could this cause uneven cylinder cooling?
The car is to be dynoed next week to improve the mapping and has wide band lambdas in both exhausts, but will not indicate individual cylinder lambdas. So I am keen to know if I have a problem before the dyno day.
The car is to be dynoed next week to improve the mapping and has wide band lambdas in both exhausts, but will not indicate individual cylinder lambdas. So I am keen to know if I have a problem before the dyno day.
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