Chevrolet 12550909 Valve, Exhaust

When servicing valves, valve seats and valve guides- popularly termed as valve jobs- due to the delicate nature of the task and its specific tools and equipment, it is best when done by professional people. If doing a home mechanic work, the heads can be taken apart and reassembled, initially cleaned and inspected and then delivered to a dealer service department or an automotive machine shop for actual valve servicing. The valves and springs will be removed by either a dealer service department or an automotive machine shop who will also either recondition or replace the valves and valve seats. The valve guides will also be reconditioned; there would be checking of spring height during assembly on reassembly of the cylinder head, replacing of spring retainers or rotators replacing keepers as required, putting in new valve seals, putting together the rest of the valve parts and checking whether installed spring height is correct. In addition to that, if necking is needed on its warped surface, it may also need surfacing at this time. A professional should perform this step because in case anything goes wrong with his hands it should be his responsibility as opposed to an ameuter who will blame it on fate or bad luck. When the professional is through with doing a valve job, you'll have your head back almost new. Afterward rinse off all traces of metal particles produced from the grinding action during machining operations as well sand bar grit from contact with any grinding wheel feeds using carbide cutters which must have been used in refacing the face of combustion chambers which had gotten dirty by carbon deposits.

When servicing valves, valve seats and valve guides- popularly termed as valve jobs- due to the delicate nature of the task and its specific tools and equipment, it is best when done by professional people. If doing a home mechanic work, the heads can be taken apart and reassembled, initially cleaned and inspected and then delivered to a dealer service department or an automotive machine shop for actual valve servicing. The valves and springs will be removed by either a dealer service department or an automotive machine shop who will also either recondition or replace the valves and valve seats. The valve guides will also be reconditioned; there would be checking of spring height during assembly on reassembly of the cylinder head, replacing of spring retainers or rotators replacing keepers as required, putting in new valve seals, putting together the rest of the valve parts and checking whether installed spring height is correct. In addition to that, if necking is needed on its warped surface, it may also need surfacing at this time. A professional should perform this step because in case anything goes wrong with his hands it should be his responsibility as opposed to an ameuter who will blame it on fate or bad luck. When the professional is through with doing a valve job, you'll have your head back almost new. Afterward rinse off all traces of metal particles produced from the grinding action during machining operations as well sand bar grit from contact with any grinding wheel feeds using carbide cutters which must have been used in refacing the face of combustion chambers which had gotten dirty by carbon deposits.

Because of the need to perform extensive work on the valves, valve seats and valve guides, often referred to as the 'valve job', it is advisable to seek the services of a professional technician since the job calls for proper alignment and use of some specific tools and equipment. A home mechanic can take off the head, scrape, clean as well as assess the valves, then reinstall the head and bring or take the head to a dealer service department or an automotive machine shop for the real servicing of the valves. Some of the duties of the dealer service department or the automotive machine shop will include the removal of the valves and the springs, the reconditioning and or replacement of the valves and valve seats, the inspection, reconditioning, and replacement of the valve guides, the checking and replacement of the valve springs, the spring retainers, the keepers as may be deemed necessary, the replacement of the valve seals with new ones and the reassembly of If the surface of the cylinder head gasket is twisted then it is also refinished. After the valve job is accomplished by the professional the head will be in good condition as if it was when it was new. On its return it should be again washed to remove all the particles of metal and other abrasive materials which could be left following the valve service or the process of milling or facing of the head and if possible all the oil holes and passages should be blown with air.

Compressed air can be used to blow out all oil holes and passages to ensure they are clean.

Servicing the valves and related components is complex and requires specialized tools and equipment, making it best suited for a professional.

The heads of the valves should be examined for pitting and burning, particularly focusing on the exhaust valves, while also checking the valve seat.

Depending on their condition, the valves may need to be re-ground or replaced. A valve should be discarded if re-grinding creates a sharp edge, as this can lead to overheating.

The first step is to remove the cylinder head and place it on a clean surface.

If significant pitting or burning is present, the valve should be refaced by a dealer and the seat recut; if refacing reduces the valve head edge to below specified limits, replacement is necessary.

They will remove the valves and springs, recondition or replace the valves and valve seats, recondition the valve guides, check and replace the valve springs, spring retainers, and keepers as necessary, replace the valve seals, reassemble the valve components, and ensure the installed spring height is correct. If the cylinder head gasket surface is warped, it will also be resurfaced.

Once the valve job is completed by a professional, the head will be in like-new condition.

Due to the complexity of the job and the specialized tools required, it is best handled by a professional.