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curious about valve gear oiling
Posted: Wed Jan 16, 2013 5:05 pm
by driggs
I'm working on a /7 motor and have a question about the supply of oil to the rocker gear...how do the rockers and their needle bearings get oiled? What path does the oil flow follow, lets say starting at the oil pump....is it engineered so that the valve cover actually fills with oil while the engine is running? Or is it more like a dribbling of oil onto the moving parts? I see the oil gallery in the base of the cylinder stud but I don't quite understand how the oil gets to the top bearing of the rocker arm from there....enquiring minds want to know....
Re: curious about valve gear oiling
Posted: Wed Jan 16, 2013 6:03 pm
by ME 109
An oil circuit diagram will explain all.
But I don't have one.
The valve gear does not receive very much oil.
Re: curious about valve gear oiling
Posted: Wed Jan 16, 2013 6:42 pm
by Kurt in S.A.
The valve cover area doesn't fill up with oil...if it did, oil would easily get by the valves into the engine or exhaust. It's more of just a dribble down the top studs. Pictures here, taken from BMW shop manual.
http://bmwmotorcycletech.info/oilsketch.htm
Kurt in S.A.
Re: curious about valve gear oiling
Posted: Wed Jan 16, 2013 11:31 pm
by melville
Pull the plugs and remove power to the coils/ignition, then remove the valve covers and turn the motor over with the starter button to see the oil flow. As Kurt said, it comes in from the top studs and gravity takes it back to the sump through the PR tubes.
Re: curious about valve gear oiling
Posted: Thu Jan 17, 2013 12:33 am
by ME 109
Oil journey.....from the sump, up through the oil pump, along the gallery to the filter canister, through the filter, along the gallery to the front main bearing, through two small holes in the main bearing, one for each rocker feed, through the galleries to the engine studs, along the engine studs (through the barrels) to the rockers, out into the valve covers, and down the push rod tubes to the sump.
The oil enters the galleries beyond the front main bearing once every crank revolution. It is not a continuous flow, so to speak.
Re: curious about valve gear oiling
Posted: Thu Jan 17, 2013 12:44 am
by robert
ME 109 wrote:Oil journey.....from the sump, up through the oil pump, along the gallery to the filter canister, through the filter, along the gallery to the front main bearing, through two small holes in the main bearing, one for each rocker feed, through the galleries to the engine studs, along the engine studs (through the barrels) to the rockers, out into the valve covers, and down the push rod tubes to the sump.
The oil enters the galleries beyond the front main bearing once every crank revolution. It is not a continuous flow, so to speak.
That was perfect. Couldn't have been explained better.
Re: curious about valve gear oiling
Posted: Thu Jan 17, 2013 9:19 am
by driggs
Kurt in S.A. wrote:The valve cover area doesn't fill up with oil...if it did, oil would easily get by the valves into the engine or exhaust. It's more of just a dribble down the top studs. Pictures here, taken from BMW shop manual.
http://bmwmotorcycletech.info/oilsketch.htm
Kurt in S.A.
Perfect! Thanks!