Monday, October 18, 2010

Toyota (Silver top and Black Top), Which is the best?

                                                             Silver Top 20 Valve 4A-GE
Fourth Generation

The fourth-generation 4A-GE engine was produced from 1991 to 1995. It has silver cam covers with chrome lettering, hence the nickname "silver top". This engine yet again features a completely new cylinder head which uses five valves per cylinder instead of four. It uses Toyota Variable Valve Timing ( system on the intake cam, an increased compression ratio (10.5:1), and the intake system was replaced with a short manifold with individual throttles and velocity stacks, however the vane-type was retained, requiring the use of a plenum. The previous 16-valve head used a sharply curved intake port, while the 20-valve engine used a very upright straight port. This engine produces 160 PS (120 kW; 160 hp) at 7400 rpm with 16.5 kg·m (119 ft·lbf) at 5200 rpm of torque.

Silver Top 20 Valve 4A-GELU

Fifth Generation 

The fifth-generation 4A-GE engine produced from 1995 to 1998 is the final version of the 4A-GE engine and has black cam covers. This engine is commonly known as the "black top" due to the color of the valve cover, and yet again features an even higher compression ratio (11:1), the air flow sensor is replaced with a MAP sensor, the diameter of the four individual throttle bodies was increased from 42 mm to 45 mm, the exhaust port diameter was increased, the intake cam lift was increased from 7.9 mm to 8.2 mm and the intake ports were significantly improved in shape, contour and also the width at opening at the head was increased. Additionally, the black top had a lighter flywheel, a larger plenum, and revised rubber velocity stacks, and was also offered in 1997 with a six-speed
This revision increased the power to 165 PS (121 kW; 163 hp) at 7800 rpm with 16.5 kg·m (119 ft·lbf) of torque at 5600 rpm. These figures were issued by Toyota and are considered optimistic. It is assumed that Toyota ran the motor without ancillaries to inflate the power ratings, as some companies did before the adoption of the SAE J1349 rating standards in 2005. Still, the 'Blacktop' has become a favorite among enthusiasts and is used as an easy power upgrade for the early Toyota Corolla models, especially for use in the drift scene. Squeezing extra power from such a highly strung N/A engine can be expensive because of the relatively high state of tuning of the stock motor, and most gains come from higher lift cams and engine management.

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