High consumption of oil due to Piston ring end gap
High consumption of oil due to Piston ring end gap
(OP)
Hello ,
I work in a Car factory and we are having problems with high consumption of oil. We have found that piston ring end gap are not parallel aprox 0,2 mm , Do you think that this could be one of the causes ?
Than you for your help.
Jorge
I work in a Car factory and we are having problems with high consumption of oil. We have found that piston ring end gap are not parallel aprox 0,2 mm , Do you think that this could be one of the causes ?
Than you for your help.
Jorge





RE: High consumption of oil due to Piston ring end gap
End gaps that are not parallel represents a leakage path that is not absolutely necessary.
I learned that ring gaps need to be absolutely parallel the hard way.
RE: High consumption of oil due to Piston ring end gap
RE: High consumption of oil due to Piston ring end gap
Side Cylinder Bore Wall
/ \ or \ /
Side Piston
RE: High consumption of oil due to Piston ring end gap
Regards
Pat
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RE: High consumption of oil due to Piston ring end gap
What is the minimum and maximum gap of the tapered ring? What is your specification for ring gap? What is the oil consumption rate? Is the excessive consumption under load, or high vacuum conditions? what style oil ring are you using? Is the piston ring set bought from a name brand manufacturer? Did this problem just arise with a previously acceptable design? What's the crankcse ventilation design like?
The 1955 SAE paper describing the Chevy V8 development includes a section about high oil use at high vacuum conditions being related to axial oil ring clearance, and improved dramatically when the oil ring was changed to the modern 3 piece axially loaded design. A very similar story, reportedly by a participating factory engineer, is on the internet about the Dodge slant six engine was being developed.
RE: High consumption of oil due to Piston ring end gap
RE: High consumption of oil due to Piston ring end gap
RE: High consumption of oil due to Piston ring end gap
Of course care is taken to keep them square and parallel.
Regards
Pat
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RE: High consumption of oil due to Piston ring end gap
The reason modern recip piston engines work as well as they do and have low oil consumption is due to the highly developed state of the modern oil control ring. The oil control ring, when working properly, creates a perfectly micro-thin layer of oil on the cylinder liner surface for the compression rings to slide over. This layer of oil is thick enough for the compression rings to achieve partial hydrodynamic contact conditions, thus preventing wear and friction. Yet it is also thin enough to keep the oil film from overheating and flashing-off.
If your engine has excessive oil consumption, it's likely due to the fact that your oil control rings are not working properly. This may be due to oil ring groove fits, piston-to-liner fits (rocking at TDC or BDC), or excessive crankcase pressures.
Good luck,
Terry
RE: High consumption of oil due to Piston ring end gap
RE: High consumption of oil due to Piston ring end gap