What is mechanical overstress?

Posted on February 6, 2018 February 10, 2018 by Ed Hare PhD. These are chip resistors that were reported to be failing with high resistance. This is a BSE SEM image of a microsection through the approximate centerline of the resistor.

What causes a valve to snap?

Possible causes include an incorrectly set valve clearance − or the valve seat insert or valve guide were not remachined centrically. An excessively large or small valve guide clearance can also have fatal consequences.

What causes excessive valve clearance?

Internal engine changes may cause the valve clearance to either increase or decrease. Wear between the cam face and cam follower or between the valve tip and the valve actuator will cause the valve clearance to increase. Excessive valve clearance will result in engine noise (ticking) if the clearance gets large enough.

What causes resistor to fail?

A fixed composition resistor normally fails in an open configuration when overheated or overly stressed due to shock or vibration. Excessive humidity may cause an increase in resistance. A variable composition resistor may wear after extensive use, and worn away particles may cause high resistance short circuits.

What is engineering overstressing?

Permanently deforming a metal by subjecting it to stresses that exceed the elastic limit.

Can a piston hit a valve?

and piston crown design, it’s possible that the valves can touch the top of the piston as it reaches TDC on the intake stroke. In this automotive version of Clash of the Titans, the valves will almost always lose. If they hit the piston, you’ll be lucky to get off with just a bent valve stem.

How do you tell if your valves are out of adjustment?

When do I need to have a valve adjustment? You should have your valve lash inspected at manufacturers recommended intervals. A sure sign that it’s time for a valve lash adjustment is if your engine is making a loud clicking or tapping noise when starting up or if you experience a loss in engine power.

Is it better to have valves loose or tight?

A reliable BMW tech said that loose valves run cooler and may provide a bit more mid-range pull. He also said he routinely adjusted customer’s valve lash on the snug side with no issues. Tighter valves mean easier starting and some small high RPM performance gains.

What is a valve stem on a tire?

The valve stem is what locks in a tire’s air and ensures it stays properly pressurized and inflated. So, if you have a slow leak or another issue with your car’s tires losing air, it might be the valve. Swapping out your valve stem is a task that can be performed right in your garage — but it requires a specialized tool.

What is the best valve stem tool?

The Steelman Rubber Booted Valve Stem Tool is an excellent choice if you need a valve stem tool that’s extra tough and built to last you a long time. The Steelman Rubber Booted Valve Stem Tool is an excellent choice if you need a valve stem tool that’s extra tough and built… .

Do you cover all tire valve stem sizes and colors?

We cover all valve stem sizes and OEM colors, so every tire valve stem replacement you do looks like it is from the factory. Our offerings include standard valve stems and TPMS valve stems designed to be compatible with factory and aftermarket tire pressure sensors.