PISTON SEGMENT RINGS 5.0 5.7 6.3 STD 3857670

Function and technical context

Piston rings in standard size (Std) are the sealing elements that work housed in the perimeter grooves of the piston, inside the engine cylinder. Its mission is threefold: to seal the combustion gases so that they do not escape into the crankcase, regulate the lubricating oil film on the cylinder wall and transfer the heat generated in combustion from the piston to the block. In Volvo Penta outboard and stationary engines of the 5.0, 5.7 and 6.3 liter ranges, as well as in the equivalent MerCruiser and OMC blocks, the correct operation of the rings is decisive to maintain working compression and engine efficiency. A worn or broken ring directly compromises the tightness of the combustion chamber, reduces cylindrical compression and can cause high oil consumption, loss of power and contamination of the lubricant with combustion gases.

When to replace this part?

The most common symptoms of piston ring wear are: bluish smoke from the exhaust (oil that burns in the combustion chamber), notable loss of compression in one or more cylinders when performing a compression test, increased oil consumption between changes and presence of gases in the crankcase (blow-by). The replacement of the rings is usually carried out coinciding with a cylinder rectification or in a general engine overhaul process, normally when the wear analysis or compression measurements indicate it. Acting preventively at the time of major engine overhaul avoids secondary damage to the block, bearings and lubrication system that would make the repair considerably more expensive.

Compatible Volvo Engines

Equivalent manufacturer part numbers