A valve spring is placed around the stem of a valve and held in place by a retainer. Its main job is to control the entire valvetrain, ensuring that the proper amount of spring pressure is applied consistently to prevent valve bounce.

Valve springs can last a long time, but they do wear. On higher mileage engines with 100,000 miles or more, it is not uncommon for the valve springs to lose tension. Springs that have lost more than 10% of their tension should be replaced.

Once the valve springs have been installed, it is important to check for coil bind. This means that when the valve is fully open, there must be a minimum of . 060” clearance between the coils of both the inner and outer springs.

The method of making valve spring retainer locks which comprises edge-bending a strip of metal into arcuate shape in a first plane, whereafter curling the leading edge of the strip at right angles to the first plane into a fragmental cylindrical shape, and cutting the curled end from the strip.

If spring tension is too light, valve float and eventual engine damage can occur. If the spring is too stiff, friction-related horsepower loss and accelerated valve train wear will result. According to cam experts, one of the most common causes of premature camshaft failure is the use of improper valve springs.

Valve rotators help to reduce the amount of carbon deposits on the valve and prevent carbon build-up on the valve seat. Cleaner valves reduce engine emissions and prevent burning and guttering of the valve face and seat.

Which of the following is a characteristic of hydraulic valve lifters? They automatically accommodate changes from part wear or temperature fluctuations. Valve stem-to-guide clearance should be measured using a: dial indicator or micrometer and ball gauge.

Pushrods are long, slender metal rods that are used in overhead valve engines to transfer motion from the camshaft (located in the engine block) to the valves (located in the cylinder head). The bottom end of a pushrod is fitted with a lifter, upon which the camshaft makes contact.

A camshaft is a rotating object— usually made of metal— that contains pointed cams, which converts rotational motion to reciprocal motion. Camshafts are used in internal combustion engines (to operate the intake and exhaust valves), mechanically controlled ignition systems and early electric motor speed controllers.

A camshaft uses egg-shaped “cams” to open and close engine valves (one cam per valve), while a crankshaft converts “cranks” (the up/down motion of the pistons) to rotational motion.

Maxing Engine Performance. Consider installing a performance camshaft. Performance cams increase the duration and timing of the valve openings during the engine stroke, increasing horsepower and making your car accelerate more quickly. Adjust the timing and tweak the new cams as necessary.

The valve cover is a thin metal or plastic cover over the top of the cylinder head. It may also be called a rocker cover. It simply prevents valve train oil spray from leaking out of the engine. A valve lifter, also called a tappet, usually rides on the cam lobes and transfers motion to the rest of the valve train.

If you hear it whistle out of the PCV valve, oil pour hole or dipstick is a sign of that air getting past the piston rings – i.e. cooked rings. And if any air bubbles out through the coolant, it indicates a head gasket leak. A compression test will show whether its the seals or the rings.

Valve Stem Seal, Failure Symptoms:

1. With A Cold Engine. One of the most noticeable signs of worn valve stem seals; will be just after a cold engine start.
2. Idle and Stop and Go Driving.
3. Off-Throttle Braking.
4. Oil Consumption.
5. Excessive Smoke.

Here is a list of the most common symptoms for bad piston rings:

1. White or gray exhaust smoke.
2. Excessive oil consumption.
3. Low power for acceleration.
4. Overall loss of power or poor performance.

Here are some symptoms of a bad valve seal that may need to be replaced:

• Performing the Cold Engine Test. One sure-fire way to tell if you have a faulty valve seal is to perform a cold engine test.
• Idling.
• High Levels of Oil Consumption.
• High Levels of Smoke.
• Engine Braking Test.
• Acceleration Power is Compromised.

A lot of oil-burning takes place because an engine’s piston rings are worn out, and thicker oil won’t fix that. Using thicker oil is also a particularly bad solution for modern cars. They use low-viscosity oils that splash easily all over the moving parts of the engine to make sure they’re all lubricated.

RE: How much should a good valve job cost? the machine work should be about 150-250 for a valve job and resurface, plus another 10-15 bucks per exhaust seat thats installed.

you can definitely do it yourself.

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.

A valve job is an operation which is performed on any four stroke cycle, internal combustion engine, the purpose of which is to resurface the mating surfaces of the poppet valves and their respective valve seats that control the intake and exhaust of the air/fuel mixture that powers the motion of the pistons after the …

A valve job may be necessary by the time an engine has 80,000 or more miles on it, or to fix a “burned valve,” compression or oil burning problem.

Although some seats may need two or three times of lapping, it is not necessary or good to over-lap the valves. It is unlikely, but possible, to remove too much, and doing so will ruin the valve seat. If you are unable to achieve a consistent grey ring, the seats are probably worn out and will require cutting.

Pros bill for half an hour to an hour. If you haven’t done it before it’s going to take you longer than 20/45 minutes. The time going to vary based on how many are out of spec. If you have to adjust all 16 it’s going to take you longer than if you only have to do 2.

Valve Lapping is basically sanding down the surface of the Valves (which allow fuel and air to flow in, and exhaust to flow out) and the Head (Holds the Camshafts and valves) where they make contact with each other.

Many things can cause a valve to drop out. Running the engine too fast (doubtful), backfire (again doubtful), misadjusted valves, weak valve, rotator or keeper. Broken valve spring.

It might take 7 hours (very rough) to replace the one head that has the broken valve, so 7 hours of labor is roughly $630. So, adding in a little for the incidentals, at minimum, it’d cost at least $1,000 if you just replaced the head to solve the problem but that assumes that no other damage is found.

Symptoms of Weak Valve Springs Weak valve springs will typically cause misfiring and a loss of power as engine speed increases. The engine may start and idle fine, or run normally up to 3500 to 4000 RPM.

Compressed air is preferred. In a pinch, I’ve seen rubber hose put in to the cylinder through the spark plug hole (make sure to leave some hanging out, or use a flange of some sort) then put the piston at TDC. The hose SHOULD make up the gap between the piston and the valves to hold them in.