Engine cylinder head exhaust valve. Porsche 356 › 61610540550

Engine Cylinder Head Exhaust Valve
sold each – 4 required per car

OE Match engine cylinder head exhaust valve for selected Porsche 356 1600 engines. This valve is suitable for engine repairs, cylinder head refurbishment and complete engine rebuilds.

Fits:

• 356 Cabriolet/Speedster, A 1600 616/1
• 356 Cabriolet/Speedster, A 1600 S 616.15
• 356 Cabriolet/Speedster, B 1600 Super 75 616.15
• 356 Cabriolet/Speedster, C 1600 616.15
• 356 Coupe, A 1600 Super 616.15
• 356 Coupe, B 1600 Super 75 616.15
• 356 Coupe, C 1600 616.15

The exhaust valve controls the flow of burnt combustion gases from the cylinder into the exhaust system. Because it operates directly in the combustion chamber, it is subjected to extremely high temperatures and repeated mechanical loading every time the engine runs.

What Does the Exhaust Valve Do?

During the engine's exhaust stroke, the exhaust valve opens to allow burnt gases to leave the combustion chamber. It then closes against the valve seat to seal the cylinder for the next combustion cycle.

Correct sealing is essential for maintaining cylinder compression, efficient combustion and smooth engine performance.

Why Do Exhaust Valves Fail?

Exhaust valves operate in a particularly demanding environment because hot combustion gases pass directly across the valve head and seat.

Over time, deterioration can result from:

• Valve face or seat wear
• Excessive heat
• Burning or pitting of the valve face
• Carbon deposits
• Valve stem or guide wear
• Incorrect valve clearances
• Poor valve seating
• Corrosion during long periods of storage

A valve that no longer seals correctly can cause loss of compression and poor engine performance.

When Should It Be Replaced?

Replacement should be considered if inspection identifies a burnt, cracked, bent, excessively worn or badly pitted valve.

Possible symptoms of valve or cylinder head problems include:

• Low cylinder compression
• Misfiring or uneven running
• Reduced engine performance
• Poor combustion
• Excessive valve train noise
• Failed compression or leak-down testing

The condition of the exhaust valves should always be assessed during a cylinder head overhaul or major engine rebuild.

Checks During Replacement

When replacing an exhaust valve, also inspect:

• Exhaust valve seat
• Valve guide
• Valve spring
• Valve collets and retainers
• Rocker arm and adjuster
• Cylinder head condition
• Remaining inlet and exhaust valves

Valve guide clearance and valve seat condition should be checked carefully before fitting a new valve.