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techtalk:ref:oil20 [2020/10/26 03:53] hippysmack [Testing 2004-up oil tank for hydro-lock] |
techtalk:ref:oil20 [2022/09/10 02:52] hippysmack [Oil Tank Pressure] |
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| ====== REF: Oiling & Lubrication ====== | ====== REF: Oiling & Lubrication ====== | ||
| ====== Oil Tank Pressure ====== | ====== Oil Tank Pressure ====== | ||
| + | See also, [[techtalk:ref:oil21#oil_tank_head_pressure|Oil Tank Head Pressure]] in the Sportsterpedia. \\ | ||
| There should not be any noticeable pressure in the oil tank due to the generated pressure being vented back into the cam chest. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5736179#post5736179)) \\ | There should not be any noticeable pressure in the oil tank due to the generated pressure being vented back into the cam chest. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5736179#post5736179)) \\ | ||
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| * But there are plenty of riders who have ridden in below freezing temperatures that haven't had a problem. | * But there are plenty of riders who have ridden in below freezing temperatures that haven't had a problem. | ||
| - | ====== Crankcase Pressure / Venting in the Oil Tank ====== | + | ====== Crankcase Pressure / Venting the Oil Tank ====== |
| - | **Venting the oil tank**: \\ | + | ==== Air Pressure and Oil Level ==== |
| - | The oil tank is by design, vented to the cam chest and out the engine breather vent(s). | + | |
| - | Neither the oil cap nor the oil tank should be vented without a one way check valve. \\ | + | |
| - | The tank is vented to the cam chest on purpose to remove condensate (that gets pumped in) from the oil tank out the single one way engine breather valve. \\ | + | |
| - | Venting the oil tank \ cap also will negatively influence crankcase pressure by letting in extra air. \\ | + | |
| - | 1/2 of the return flow is air because the return pump is twice as big as the feed pump. ((ryder rick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1904589&page=4)) \\ | + | |
| - | That air is full of condensate. A slightly negative (to atmospheric) pressure in the tank facilitates vaporization of the condensate. \\ | + | |
| - | **Air pressure and oil level**. \\ | ||
| Air inside the tank doesn't get there because of CC pressure alone. Ambient air resides in the upper portion of the tank above the oil level. \\ | Air inside the tank doesn't get there because of CC pressure alone. Ambient air resides in the upper portion of the tank above the oil level. \\ | ||
| The air was there first. Then the oil was added. If you add too much oil, there will be even less air in the tank. \\ | The air was there first. Then the oil was added. If you add too much oil, there will be even less air in the tank. \\ | ||
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| {{:techtalk:ref:oil:oil_pressure_drawing_1_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) {{:techtalk:ref:oil:oil_pressure_drawing_4_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | {{:techtalk:ref:oil:oil_pressure_drawing_1_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) {{:techtalk:ref:oil:oil_pressure_drawing_4_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | ||
| + | \\ | ||
| Since it's not the oil pump scavenger's job to separate the oil/air mist, both crankcase pressure and oil end up in the oil tank. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5736179#post5736179)) \\ | Since it's not the oil pump scavenger's job to separate the oil/air mist, both crankcase pressure and oil end up in the oil tank. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5736179#post5736179)) \\ | ||
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| {{:techtalk:ref:oil:oil_pressure_drawing_2_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | {{:techtalk:ref:oil:oil_pressure_drawing_2_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | ||
| {{:techtalk:ref:oil:oil_pressure_drawing_3_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | {{:techtalk:ref:oil:oil_pressure_drawing_3_by_hippysmack.jpg?direct&450|}} ((drawing by Hippysmack)) | ||
| + | \\ | ||
| The piston movements in the HD engine are not in apposing positions to balance out the displacement of air. \\ | The piston movements in the HD engine are not in apposing positions to balance out the displacement of air. \\ | ||
| They are mounted on the same crank pin and oscillate into a small volume crankcase. \\ | They are mounted on the same crank pin and oscillate into a small volume crankcase. \\ | ||
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| See more here [[techtalk:ref:engmech04|Evo Crankcase Pressure]] on engine breathing, crankcase pressure and blowby in the REF section of the Sportsterpedia. \\ | See more here [[techtalk:ref:engmech04|Evo Crankcase Pressure]] on engine breathing, crankcase pressure and blowby in the REF section of the Sportsterpedia. \\ | ||
| - | **If the oil tank vent line is plugged up**, the oil pump will still send air/oil pressure into the tank. \\ | + | ==== Stopped Up Vent Line ==== |
| + | If the oil tank vent line is plugged up, the oil pump will still send air/oil pressure into the tank. \\ | ||
| The air pressure can't leave the tank but the oil is recirculated from the tank into the engine by the feed side of the pump. \\ | The air pressure can't leave the tank but the oil is recirculated from the tank into the engine by the feed side of the pump. \\ | ||
| Pressure will build in the tank until the cap blows, oil leaks from the cap or the oil tank splits (plastic). \\ | Pressure will build in the tank until the cap blows, oil leaks from the cap or the oil tank splits (plastic). \\ | ||
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| And that can lead to wetsumping with more oil in the sump than usual. \\ | And that can lead to wetsumping with more oil in the sump than usual. \\ | ||
| - | **Removing the oil cap with the engine running**. \\ | + | ==== Removing the Oil Cap with the Engine Running ==== |
| Removing the oil cap on a hot idling engine (so far rigid S models only), may lower engine speed if the breather valve(s) aren't working properly. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5763694#post5763694)) \\ | Removing the oil cap on a hot idling engine (so far rigid S models only), may lower engine speed if the breather valve(s) aren't working properly. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5763694#post5763694)) \\ | ||
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| Read more on [[techtalk:ref:engmech04#fluid_drag|Fluid Drag]] above. \\ | Read more on [[techtalk:ref:engmech04#fluid_drag|Fluid Drag]] above. \\ | ||
| + | |||
| + | ==== Venting the Oil Tank ==== | ||
| + | |||
| + | The oil tank is by design, vented to the cam chest and out the engine breather vent(s). | ||
| + | Neither the oil cap nor the oil tank should be vented without a one way check valve. \\ | ||
| + | The tank is vented to the cam chest on purpose to remove condensate (that gets pumped in) from the oil tank out the single one way engine breather valve. \\ | ||
| + | Venting the oil tank \ cap also will negatively influence crankcase pressure by letting in extra air. \\ | ||
| + | 1/2 of the return flow is air because the return pump is twice as big as the feed pump. ((ryder rick of the XLFORUM http://xlforum.net/forums/showthread.php?t=1904589&page=4)) \\ | ||
| + | That air is full of condensate. A slightly negative (to atmospheric) pressure in the tank facilitates vaporization of the condensate. \\ | ||
| + | |||
| + | * **1977-2003 Sportsters use oil pump scavenge and the oil tank to remove __some__ of the crankcase air into the cam chest**. \\ However, there are also holes in the cam walls for crankcase air to escape into the cam chest and head drains to the crankcase. \\ These holes carry crankcase air out to the cam chest without using the oil pump. \\ The oil pump does still have bigger feed gerotors that will pick up crankcase air to the oil pump also. \\ But the crankcase is not bottled up like 2004-up motors. | ||
| + | |||
| + | * **2004-Present Sportsters use oil pump scavenge and the oil tank to move __most__ of the crankcase air into the cam chest**. \\ Some goes out the pinion shaft bearing clearances but the only other outlet for piston downstroke air is the oil pump. \\ The source of air intake to the crankcase on piston upstroke is the pinion shaft bearing clearance. \\ The oil pump is steadily pushing oil and air out of the crankcase into the oil tank and then into the cam chest / rocker boxes to the head vents. | ||
| + | |||
| + | 1977-2003 Venting: \\ | ||
| + | {{:techtalk:ref:oil:1998-2003_sportster_oil_tank_oem_crankcase_pressure_2_to_tank_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) {{:techtalk:ref:oil:1998-2003_sportster_oil_tank_vented_crankcase_pressure_to_tank_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) \\ | ||
| + | |||
| + | 2004-up Venting: \\ | ||
| + | {{:techtalk:ref:oil:2004-2006_sportster_oil_tank_oem_crankcase_pressure_to_tank_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) {{:techtalk:ref:oil:2004-2006_sportster_oil_tank_vented_crankcase_pressure_to_tank_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) \\ | ||
| ====== Oil Tank's Role vs Wetsumping ====== | ====== Oil Tank's Role vs Wetsumping ====== | ||
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| The vent hose won't get blocked full of oil. The oil will seal the vent tube off in the tank by hydraulic lock and not allow the air to leave the tank. \\ | The vent hose won't get blocked full of oil. The oil will seal the vent tube off in the tank by hydraulic lock and not allow the air to leave the tank. \\ | ||
| Then the pressure builds in the tank (oil pump is pressurizing the return hose but the vent would now be blocked). \\ | Then the pressure builds in the tank (oil pump is pressurizing the return hose but the vent would now be blocked). \\ | ||
| - | The pressure is not sent to the cam chest / engine since the vent tube would now be blocked. \\ | + | The pressure should not be sent to the cam chest / engine since the vent tube would now be blocked. \\ |
| The 2007-2009 oil tank (62888-04A) has a wider trough in the top section that the vent tube rises up into (the slot system was deleted). \\ | The 2007-2009 oil tank (62888-04A) has a wider trough in the top section that the vent tube rises up into (the slot system was deleted). \\ | ||
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| In late 2009, the MoCo released a new oil tank version (62888-04B) for 2004-2009 models. It has the 10 psi relieve valve that is standard on the 2010 oil tank. \\ | In late 2009, the MoCo released a new oil tank version (62888-04B) for 2004-2009 models. It has the 10 psi relieve valve that is standard on the 2010 oil tank. \\ | ||
| + | The MoCo also moved the return tueb to the right side and got it away from the vent tube completely. \\ | ||
| + | |||
| + | **Yet still, the 10 PSI relief valves will open even in the later upgraded oil tanks**. \\ | ||
| + | 10 PSI is very high for crankcase pressure but the 10 PSI valve in the tank isn't the whole story. \\ | ||
| + | The pump is capable of making 100 PSI (either the feed or return side) and probably much more when the vent is blocked. \\ | ||
| + | So if the vent is hydro-locked with oil, tank pressure could get very high and that's when you may end up blowing the cap off or cracking the tank seam. \\ | ||
| To recap: | To recap: | ||
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| The plastic oil tank can be tested during operation to see if oil is blocking the vent tube. \\ | The plastic oil tank can be tested during operation to see if oil is blocking the vent tube. \\ | ||
| + | This way, you'll know if it is the oil tank or the bottom end that needs to be addressed. \\ | ||
| By installing a manometer or a vacuum gauge to monitor crankcase pressure and an oil gauge to measure return pressure, it can be deduced as; \\ | By installing a manometer or a vacuum gauge to monitor crankcase pressure and an oil gauge to measure return pressure, it can be deduced as; \\ | ||
| * If the oil gauge pressure rises but the manometer doesn't change or doesn't change a lot, the oil tank is being pressurized. | * If the oil gauge pressure rises but the manometer doesn't change or doesn't change a lot, the oil tank is being pressurized. | ||
