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--- techtalk:ih:oil01 [2020/06/05 21:04]
hippysmack [Engine Oil Pressure (57-85)]
+++ techtalk:ih:oil01 [2020/08/08 00:34]
hippysmack [Sub Documents]
@@ Line 415: / Line 415: @@
 |  Oil line sleeves. ((photos by sc72 of the XLFORUM http://xlforum.net/forums/showthread.php?t=1704463))  ||
-|{{:techtalk:ih:oil:83_model_oil_line_sleeves_1_by_sc72.jpg?direct&250|}}|{{:techtalk:ih:oil:83_model_oil_line_sleeves_1_by_sc72.jpg?direct&250|}}|
+|{{:techtalk:ih:oil:83_model_oil_line_sleeves_1_by_sc72.jpg?direct&250|}}|{{:techtalk:ih:oil:83_model_oil_line_sleeves_2_by_sc72.jpg?direct&250|}}|
 ===== Rocker Box =====
 The feed to the rockers is not a large diameter passage and not a lot of oil goes to the rocker gear. ((Ferrous Head of the XLFORUM http://xlforum.net/forums/showthread.php?t=753175&highlight=split+rocker+box)) \\
@@ Line 424: / Line 424: @@
 ====== Transfer Valve (76 and earlier) ======
-The foregoing by Dr Dick ((http://xlforum.net/forums/showpost.php?p=3886388&postcount=40))
+===== Sub Documents =====
+  * [[techtalk:ih:oil01t|Further Study of the Transfer Valve Operation and Affects of Plugging the Valve]]
+  * [[techtalk:ih:oil01u|Plugging the Transfer Valve]]
+The transfer valve is not the crankcase vent (aka foo-foo valve). The crankcase vent fitting wasn't used until the 1977 model year. \\
+It was installed in 77-78 engines only in the cam cover and vents crankcase pressure (air) to atmosphere. \\
+[[techtalk:ih:engmech07#breather_valve1|Explanation for the foo-foo valve is here]] in the Sportsterpedia. \\
+The transfer valve is installed in the left case between the primary and crankcase compartments. ((needspeed of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280)) \\
+There is only one moving part in the transfer valve assembly which is the triangular shaped disc in the pics below. \\
+It's a triangular piece of .009" thick stainless steel that can move about .015" left to right in the valve. There is no spring. \\
+In a running engine, it is a one way valve that lets air and oil pass through it from primary case to flywheel case. \\
+[[https://www.youtube.com/watch?v=EOu0uR2ulF8|Click here]] to see a video of the direction of flow. \\
+Positive crankcase pressure pushes the valve disc to the left and seals a small hole preventing flow into the primary. \\
+Vacuum in the crankcase pulls the disc to the right up against a stop that has a larger hole. \\
+The 3 cuts that make the disc a triangle shape allows air/oil to flow around it into the crankcase. \\
+Without the engine running and with no spring to maintain a tight seal, oil can slowly leak through and let wet sumped oil pass into the primary. \\
+On engine start up the excess oil in the primary should be transferred back into the engine. \\
 The transfer valve is staked into position. ((Ferrous Head of the XLFORUM http://xlforum.net/forums/showthread.php?t=581947&page=6)) \\
 Look very close around the edges and you'll see two spots that have been lightly punched. \\
-To remove it; ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=776527)) \\
-  - You can use a hammer and punch stake mark out of the valve slot. Be careful when hammering on your cases.
-  - You can find a socket that same size as the OD of the valve. Lay it on the valve & give it some face hammer shots. Again, be careful.
-  - Or get 2 hammers, 2 drifts, 2 guys, one for each slot. Get in rhythm so both hit at same time. \\ You don't want to brutal. It will break loose if you repeat 2&3. Be careful not to mash the valve into the case. That would restake the valve. Again, be careful.
 |{{:techtalk:ih:oil:transfer_valve_by_fourcams.jpg?direct&250|}}|{{:techtalk:ih:oil:transfer_valve_1_by_ironheadjunkie.jpg?direct&300|}}|{{:techtalk:ih:oil:transfer_valve_2_by_ironheadjunkie.jpg?direct&300|}}|
@@ Line 438: / Line 454: @@
+The thread pattern is 3/4"-16. ((needspeed of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280))  \\
+There is nothing to wear out. However anything that stops the movement of the reed (rust or dirt) means the valve won't work. \\
+The one taken apart here was gummed up with old oil that had a tar like consistency. \\
+{{:techtalk:ih:oil:transfer_valve_exposed_pic_1_by_needspeed.jpg?direct&800|}} ((photo by needspeed of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280)) \\
+Also, as a test, a container of 20w-50 oil at room temperature was allowed to gravity drain from the transfer valve. \\
+It took 48 hours for 100 milliliters of oil to drip through the valve. \\
+{{:techtalk:ih:oil:transfer_valve_exposed_pic_3_by_needspeed.jpg?direct&300|}} ((photo by needspeed of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280)) \\
+Here are a few drawings detailing the assembly: \\
+{{:techtalk:ih:oil:transfer_valve_exposed_pic_2_by_needspeed.jpg?direct&500|}} ((drawing by needspeed of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280)) \\
-The purpose of the transfer valve is to keep your garage floor clean. \\
-It's an oil control device to control the oil in order to keep it in your bike. \\
-There is so much speculation on this subject that sometimes the myth becomes the reality.
-  * The transfer valve is a part of a bigger system. \\ A system that we often break down into its components. \\ Then we deal with the (target component) often losing sight of the big picture. \\ It's our nature as mechanical guys. \\ Pin point the problem and then bring the hammers of Hell to bear on it. \\ If we can let go of that instinct for a moment this will make perfect sense. \\ So you want to think big picture here.
+===== Removing / Installing the Transfer Valve =====
-  * **The Transfer Valve**:
+The transfer valve is staked into place and it is steel into alloy which is always problematic. ((Ferrous Head of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280&page=3)) \\
-  - **Fact**: If you blow thru the valve it only allows flow from primary to engine.
+If you do remove/replace the valve, make sure it is staked back in place when you finish. Use some Loctite on the threads also.\\
-  - **Fiction**: That means its a one way check valve. Bad assumption. \\ It allows flow one way only when pressure is different one side of valve to other. See #3.
-  - **Fact**: When taken apart carefully as not to bend the triangular reed we find no spring that 'checks' the valve when pressure differential is absent. \\ So it's allowed to 'leak' in state of equilibrium.
-  - **Fiction**: There's something missing from this valve. \\ That's why its not checking and allowing leaking oil into my primary as I found when I left the primary cover off an saw the trail of oil from the valve. \\ **If you dismiss the assumptions** and stick with what we can prove this truth emerges: \\ **The transfer valve is a one way feed when engine is running but not when engine is static**. \\ (then it's relaxed and oil leaks from motor thru it)
-  - **Fact**: Oil is leaking out of your valve when the primary cover is off. \\ (it's leaking when the primary cover is on too)
-  - **Fiction**: There's only supposed to be a small amount of oil in the motor so there's something else wrong too. What could that be? \\ Aha, it's got to be the check valve in the oil pump leaking. \\ (This is the spot you go off course chasing ghosts. Because your motor is not running, oil is leaking into it before it even gets to the check valve).
-  * You are told to inspect the check valve in response to any noticeable change that increases oil exiting thru the breather tube. \\ Because a check that leaks will shorten the time it takes to fill the motor enough to puke.
-  * Even a perfectly sealed check can't stop oil that's getting in thru a different path.
-  * If we slow down now and think, we get to this: \\ In order for the pump check to leak, oil has to get to the tank side of pump check. \\ In order to get there its got to sneak past gear clearance in pump (which it obviously does). \\ But this is not the only place this errant oil can go:
-|On the way to the check, it finds clearance here, where \\ the breather valve fits thru the upper oil pump housing.|Where it leaks into the space between the breather \\ sleeve and housing, exiting at the first place it can \\ (the bottom of slot in the upper housing).|Now, it's filling the breather passage that leads to the \\ crank case. This passage is located lower than \\ the floor of the cam chest.|
+  * You can use a hammer and punch to stake mark out of the valve slot. Be careful when hammering on your cases. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=776527))
-|{{:techtalk:ih:oil:transfer_valve_explained_1_by_dr_dick.jpg?direct&300|}}|{{:techtalk:ih:oil:transfer_valve_explained_2_by_dr_dick.jpg?direct&300|}}|{{:techtalk:ih:oil:transfer_valve_explained_3_by_dr_dick.jpg?direct&300|}}|
+  * You can find a socket that same size as the OD of the valve. ((Dr Dick of the XLFORUM http://xlforum.net/forums/showthread.php?t=776527)) Lay it on the valve & give it some face hammer shots. Again, be careful. \\ Or get 2 hammers, 2 drifts, 2 guys, one for each slot. Get in rhythm so both hit at same time. \\ You don't want to brutal. It will break loose if you repeat 2&3. Be careful not to mash the valve into the case. That would re-stake the valve. Again, be careful.
+  * You can use a Snap-On Drag Link socket to remove the transfer valve. ((The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077190)) You may have to grind it to fit the slots in the oil transfer valve. ((rivethog of the XLFORUM http://xlforum.net/forums/showthread.php?t=776527)) \\ However Snap-On has a 15/16" wide version, stock # A17A, that fits quite well with no grinding needed. ((The Doctor71 of the XLFORUM http://xlforum.net/forums/showthread.php?t=776527))
-  * So, oil is now filling the crankcase and not the cam chest. \\ The factory made sure that it happened like this. \\ They wanted this unchecked oil to stay out of the cam chest so that your bike is less likely to puke oil.
+|Special tool to remove / install transfer valve. ((photo by Ferrous Head of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077280&page=3))|
-  * They didn't want the oil to just sit in the case sump either because it would just end up in the cam case soon after the bike was started.
+|{{:techtalk:ih:oil:transfer_valve_removal-installation_tool_by_ferrous_head.jpg?direct&300|}}|
-  * They wanted to somehow 'transfer' it to a reservoir allowing it to re-enter the engine in a controlled volume that the return pump could handle without being drowned.
-|Look at the position of the valve compared to the \\ breather passage. It's about even.|Go back to the 1st case pic. Note, the floor of the cam \\ chest is about even to the bottom of the pinion race. \\ Now look at the position of breather passage in \\ regards to floor of cam chest. Chest floor is higher, \\ breather passage lower. Crap flows downstream.|
+----
-|{{:techtalk:ih:oil:transfer_valve_explained_4_by_dr_dick.jpg?direct&300|}}|{{:techtalk:ih:oil:transfer_valve_explained_5_by_dr_dick.jpg?direct&300|}}|
-  * So oil flowing unchecked into the pump from the oil supply line leaks clear thru engine into primary before it can start to fill the cam chest. \\ On the primary side though, there is plenty of room to fill with the errant oil.
-  * The transfer valve 'transfers' "pre pump check" oil leakage out of the motor and into the primary. \\ Where it re-enters the engine on startup in a controlled volume that the return pump could handle without being drowned.
-  * In other words, it 'transfers' it back to engine when bike starts.
-  * This is the improvement refined from the 52-54 siphon tube that used the same valve guts.
-  * It does makes perfect sense don't it?
-  * Now, given some thought you will see why the valves aren't used on the racers.
-  * The '77 style oil system did away with the unchecked supply leakage. (so there is no reason to 'transfer' what isn't there).
-  * **It's name is absolutely 100% correct: It's the transfer valve**.
-  * The factory 'got it right' with this part.
-  * **Keep an eye on the big picture**.
 ====== Wet Sumping ======

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