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--- techtalk:ref:oil20 [2020/10/22 23:12]
hippysmack [07-09 Oil Tank (62888-04A) Internals]
+++ techtalk:ref:oil20 [2022/09/10 02:52]
hippysmack [Oil Tank Pressure]
@@ Line 2: / Line 2: @@
 ====== REF: Oiling & Lubrication ======
 ====== 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)) \\
@@ Line 53: / Line 54: @@
   * **Oil tank blew up in cold weather**. ((Screw Loose Dan of the XLFORUM http://xlforum.net/forums/showthread.php?t=2008472&highlight=oil+tank+spewed))
     * 04-up models have plastic oil tanks. The belief is that some moisture gets frozen in the vent line on 04-09 tanks causing the rupture.
-    * It's a plastic tank so it is not going to be anything like a pressure cooker if it does happen, just messy..
+    * It's a plastic tank so it is not going to be anything like a pressure cooker if it does happen, just messy.
     * The worst of it is replacing all the parts (and not being able to ride while waiting for parts to arrive).
     * The newer upgraded tanks have a better venting design to prevent this.
       * In 2010, the MoCo put a 10 psi relief valve in the oil tank (presumably to prevent this sort of issue).
-      * The relief valve will prevent having to replace the oil tank but the jury is still out on the actual cause of the problem.
+      * The relief valve will help prevent having to replace the oil tank.
+    * The cause for plastic oil tanks leaking has been discussed in the XLForum. [[http://xlforum.net/forums/showthread.php?t=74331|See this link]] to that discussion. We may have discovered the root cause. \\ Also see [[techtalk:ref:oil20#up_oil_tank_leak_issue|2004-Up Oil Tank Leak Issue]] below for the bulk of that conversation.
     * This has happened to a handful of XLFORUM members (statistically, a pretty small number).
     * 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. \\
-/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. \\
 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. \\
@@ Line 88: / Line 83: @@
 {{: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)) \\
@@ Line 99: / Line 94: @@
 {{: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))
+\\
 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. \\
@@ Line 113: / Line 108: @@
 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. \\
 Pressure will build in the tank until the cap blows, oil leaks from the cap or the oil tank splits (plastic). \\
@@ Line 122: / Line 118: @@
 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)) \\
@@ Line 138: / Line 134: @@
 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. \\
+/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.
+-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)) \\
+-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 ======
@@ Line 207: / Line 222: @@
 The 2004-2009 oil tanks have had many problems with the seam between the top and bottom section leaking. \\
 Some have noticed this only during cold temperatures and some have had this problem at warmer temps. \\
+But a cracked oil tank is not just restricted to those years as -04B and 2010-up tanks with the oil pressure relief have also been known to crack / leak. \\
 The 2004-2006 factory installed oil tank (62888-04) seems to have the worst problems. \\
@@ Line 227: / Line 243: @@
 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). \\
-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). \\
@@ Line 235: / Line 251: @@
 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**. \\
+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:
@@ Line 247: / Line 269: @@
 The pic below is an 04-06 oil tank with the top and bottom separated. You can see how high the oil has to rise to get to the vent tube. \\
-Oil basically has to fill up the small compartment from the left side to the first baffler first. ((photos by cootertwo of the XLFORUM http://xlforum.net/forums/showthread.php?threadid=148936)) \\
+Oil basically has to fill up the small compartment from the left side to the first baffler first. \\
-Click on a pic to enlarge: \\
+Click on a pic to enlarge: ((photos by cootertwo of the XLFORUM http://xlforum.net/forums/showthread.php?threadid=148936)) \\
 {{:techtalk:ref:engmech:oil_tank_3_by_cootertwo.jpg?direct&300|}} \\ \\ {{:techtalk:ref:engmech:oil_tank_1_by_cootertwo.jpg?direct&300|}} {{:techtalk:ref:engmech:oil_tank_2_by_cootertwo.jpg?direct&300|}} {{:techtalk:ref:engmech:oil_tank_4_by_cootertwo.jpg?direct&300|}}
 ==== 07-09 Oil Tank (62888-04A) Internals ====
-Click on a pic to enlarge: \\
+Here is the 07-09 oil tank cut open. \\
+You can see the partitions (or baffles) and that the vent area in the top section has been widened out and the slot is gone. \\
+You can also see the emulsion (mayo) on the left side of the tank. \\
+With the bike on the stand, the small cavity allows that amount of oil to cool faster than if it were all lumped in with the sumped area on the right. \\
+When you got a few quarts of hot oil pooled in the tank, it takes longer for it to cool. And the air has more time to gas off. \\
+With oil staying in that smaller cavity by itself, it cools faster and the air emulsifies with the oil. \\
+Next startup/heat cycle, the air in emulsion should burn off after the oil gets to operating temp. \\
+Click on a pic to enlarge: ((photos by npaisnel of the XLFRORUM http://xlforum.net/forums/showthread.php?t=74331&page=3)) \\
 {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic5_by_npaisnel.jpg?direct&300|}} {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic6_by_npaisnel.jpg?direct&300|}} {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic4_by_npaisnel.jpg?direct&300|}} \\
 {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic1_by_npaisnel.jpg?direct&200|}} {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic2_by_npaisnel.jpg?direct&200|}} {{:techtalk:ref:oil:07-09_xl_oil_tank_62888-04a_pic3_by_npaisnel.jpg?direct&200|}} \\
+==== Testing 2004-up oil tank for hydro-lock ====
+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; \\
+  * 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 water blows out the open end of the manometer, the tank is not holding pressure and it's the crankcase air that is too high. \\ (you won't retain any water in a 3 foot manometer if the pressure reaches 1.5 PSI)
+  * If crankcase pressure is high on an Hg pressure gauge, same as with the manometer. The tank isn't being pressurized.
+{{:techtalk:ref:oil:testing_the_oil_tank_by_hippysmack.png?direct&400|}} ((drawing by Hippysmack)) \\

Trace: • REF: Tools - 142 • REF: Service Procedures 10 • W E L C O M E ! • REF: Body Parts

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