|Chevy 350 Engine on Postal Trucks|
The configuration of the Chevy 350 engine on postal trucks is commonly V8. The V angle to be normally found for a V8 is by far 90?. What this configuration does is allows for a wide, low engine which has features of optimal firing and vibration. The 90? angle of the Chevy 350 engine evens the firing cycle.
The V8 is of two classic types and the difference between them is of the crankshaft. The two types are known as the cross-plane and flat-plane. The cross-plane V8 is the one most typically used on postal trucks. Each and every crank pin is at a 90? angle from the one earlier. When this is seen from the end the crankshaft takes the shape of a cross. A very good stable balance is achieved by the cross-plane. However, to maintain this balance, heavy counterweights are required on the crankshaft. The heavy counterweights consequently make the cross-plane V8 Chevy 350 engine a slow-revving engine. The cross-plane engine is unable to speed up or slow down very quickly in comparison to other models. This is a result of the greater rotating mass.
The overall firing of the cross-plane V8 is regular while the same is not the case with each bank. As a result of this there is a need to connect the exhaust pipes between the two banks. This results in the design of an optimal exhaust system. The cross-plane design is neither obvious nor simple to design. The V8 Chevy 350 is the preferred engine on postal trucks. These engines generally have displacements in excess of 6L (360 in3).
The first-generation Chevy 350 engines on postal trucks used cast iron engine blocks and two-bolt main bearing caps and the dipstick was located on the driver's side. They had dry weight (without oil or coolant) of approximately 665 lb which was dependent on the manifold and carburetion. The bore was 4.125 in (104.8 mm) and the stroke 3.25 in (82.5 mm). It had a base turbo-thrust with a four-barrel carburetor producing 250 hp. It moved on to a special tri-power triple-two-barrel super turbo-thrust producing 280 hp. A special turbo-thrust with a single large four-barrel increased the output to 305 hp. Mechanical lifters and the tri-power carburetor brought the thrust up to 315 hp and now the tri-power with 3x2 barrel has upped it to 350 hp (261 kW).
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