Can valves be reused?
Every effort needs to be made to make sure reclaimed valves are indeed reusable, and have been properly inspected and reconditioned before they go back into an engine. Replacing a burned valve won’t fix a compression problem if the underlying cause is a hot spot in the cylinder head.
What should I expect from a valve job?
The list of things included in a “complete” valve job will vary from job to job. First, a visual inspection looking for broken and damaged parts. Completely disassemble the head, so all of the parts can be cleaned and inspected. Inspect the cylinder head casting for, cracks or other damage.
What do you need to know about exhaust valve jobs?
Exhaust valves and springs often need to be replaced. Valve guides and/or seats may have to be replaced. The head may be warped or cracked, requiring additional repairs. The list of things included in a “complete” valve job will vary from job to job.
What causes the valve to contact the top of the piston?
The valves contacting the top of a piston, is due to incorrect engine synchronization. As a result, of timing chain/ belt breakage and incorrect fitting, of new belts and chains. The other common type of valve failure is burnt valves.
When does a valve job need to be replaced?
Once the head passes this point, it is also checked for flatness. The surface of the head must be flat to seal the head gasket against the block. Excessive warpage, roughness or any damage can cause the head gasket to fail. If the head exceeds the maximum allowable out-of-flatness specs, it must be resurfaced or replaced.
How is a valve job done on a cast iron cylinder?
So look for a shop or service facility that does quality work. A valve job typically begins by disassembling, cleaning and inspecting the cylinder head. Cast iron heads are “Magnafluxed” to check for hairline cracks. This involves applying a strong magnetic field to the head and sprinkling iron powder on it.
What’s the best way to do a valve job?
The best way would be by, pressure testing. Inspect valves, seats, springs, guides, and other valve train components, for wear and damage. At this point the shop should be able to come up with, a firm quote for the complete job. Replace any parts deemed not repairable.
Can a cast iron valve head be replaced?
Most install new guides, guide liners or bore out the old guides to accept new valves with oversized stems. Aluminum heads have cast iron or bronze guides that can be replaced but most cast iron heads do not. If the valves are to be reused, they will be inspected, checked for straightness then refaced.