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Engine Valves
| Q : |
Why are Caterpillar special hard faced valves different from the competitors? |
| A : |
Because Cat requires more facing material and tighter quality control standards. For example, industry standards call for a 3400-size intake valve to have a minimum 0.0165-inch hard face thickness while Caterpillar calls for 0.044-inch minimum or about 160 percent more. |
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| Q : |
Why does Caterpillar insist on more facing material than the industry standard? |
| A : |
Because we believe in building in greater value. Cat valves are designed to be reground and that is why the face thickness is important at the top and bottom edge of the valve. If these dimensions are too small, a regrind can remove the hard facing, which will seriously reduce wear resistance. |
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| Q : |
Are all Caterpillar heavy-duty engine valves the same? |
| A : |
No. For example, the Cat 3306 has 5 different intake valves and 5 different exhaust valves. The valve used depends on if the engine is direct injection, precombustion chamber, turbocharged, or naturally aspirated, or, if it runs on natural gas, LP, or diesel fuel. |
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| Q : |
What happens if you use the wrong valve in a high-output engine? |
| A : |
A high-output engine will have hotter exhaust temperatures, and a valve for a lower-rated engine will wear faster, burn, and warp. |
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| Q : |
What are other causes of valve failure? |
| A : |
Valves can also fail due to loose seat inserts, poor grinding machine maintenance, broken valves springs, too much valves lash, and engine overspeed, to mention only a few. |
ATAAC (Air to Air After Cooling)
| Q : |
How does air to air after cooling work? |
| A : |
Charge air for combustion, compressed and heated by the turbocharger, is vented to a chassis-mounted heat exchanger at temperatures approaching 300 degrees Fahrenheit. Ambient air flowing across the heat exchanger dramatically lowers the temperature of the charge air, which is then delivered to the engine intake manifold. |
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| Q : |
How does air to air after cooling compare to jacket water after cooling (JWAC)? |
| A : |
Air to air after cooling provides better fuel economy, improved response, lower emissions, and longer component life. |
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| Q : |
Why should I use a fluids analysis program? |
| A : |
Fluid analysis program detects problems early so they can be fixed before leading to a complete drive train overhaul. |
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| Q : |
How can I extend the life of my machine? |
| A : |
Installing Caterpillar? remanufactured drive train components is one of the best ways to keep costs low and still get Caterpillar's quality guarantee more. |
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| Q : |
How can I contact branch closest to my business? |
| A : |
Branch Locator. |
Rings and Pistons
| Q : |
Why should I buy Cat pistons? |
| A : |
At a glance, a ?will-fit? replacement piston may look just like a Cat piston. They are not the same. There are many small details that make a big difference. |
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| Q : |
Cat piston have a cast-in iron ring band. Why? |
| A : |
The cast-in band increases durability and reusability. It provides a tough, durable ring seat. It won?t let normal ring flex wear out the ring groove prematurely. |
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| Q : |
What are the notches at the top of some pistons for? |
| A : |
These are valve pocket which permit clearance between valve and piston at the top dead center. Check for sharp corners on these pockets. Sharp corners can break off leaving metal pieces to score the cylinder wall. Caterpillar rounds off these corners on most pistons. It is a more expensive method of manufacturing found only on top quality pistons |
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