Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision Next revision | Previous revision Last revision Both sides next revision | ||
|
techtalk:ref:genmsr07 [2020/08/30 01:13] hippysmack [Crankshaft Out of True] |
techtalk:ref:genmsr07 [2024/01/17 21:26] hippysmack |
||
|---|---|---|---|
| Line 3: | Line 3: | ||
| ====== Diagnosing Catastrophic Engine Failure in Evo Engines ====== | ====== Diagnosing Catastrophic Engine Failure in Evo Engines ====== | ||
| \\ | \\ | ||
| - | Determining the exact cause of an engine seizing up is often not that easy. However, failure analysis is essential to solving future problems and learning in real time. \\ | + | Determining the exact cause of an engine seizing up is often not that easy. \\ |
| + | However, failure analysis is essential to solving future problems and learning in real time. \\ | ||
| It's kind of a cascading problem since when one part fails, other parts are damaged also and the hunt begins uncovering similar causes and affects. \\ | It's kind of a cascading problem since when one part fails, other parts are damaged also and the hunt begins uncovering similar causes and affects. \\ | ||
| It could be described as a "Chicken or the Egg Syndrome". Spun cam bushings are usually thought of as a poor oiling issue. \\ | It could be described as a "Chicken or the Egg Syndrome". Spun cam bushings are usually thought of as a poor oiling issue. \\ | ||
| This might cause enough heat to expand their bores and loosen the bushings, allowing them to seize to the spinning cams. \\ | This might cause enough heat to expand their bores and loosen the bushings, allowing them to seize to the spinning cams. \\ | ||
| But there many more considerations for what spun the bushings than just an oiling problem as you can see below. \\ | But there many more considerations for what spun the bushings than just an oiling problem as you can see below. \\ | ||
| + | |||
| + | |||
| + | If something like this comes out when you do an oil change, find out if it's metal or brass / bronze and start diagnosing where it came from. \\ | ||
| + | |||
| + | {{:techtalk:ref:genmsr:brass-bronze_found_in_oil_by_ngot8r.jpg?direct&300|}} ((photo by NGOT8R of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/198661-uh-oh-brass-flakes-dust-a-lot-of-it-too-in-my-oil?t=2075491)) \\ | ||
| ====== The Teardown ====== | ====== The Teardown ====== | ||
| + | * Diagnosis begins before and during teardown as well as during installation of new parts. | ||
| + | * Inspect and mic everything as you tear it down as well as during the install. | ||
| * Take pictures of everything (outside and inside before you remove anything, during and after). \\ After you have the entire engine spread out in pieces is the last time to wonder if you had a pinched oil line since you can't prove it then. | * Take pictures of everything (outside and inside before you remove anything, during and after). \\ After you have the entire engine spread out in pieces is the last time to wonder if you had a pinched oil line since you can't prove it then. | ||
| * Work backwards from the order of installation when removing anything. Just crack them loose in reverse order, then back them off in reverse order. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1756724&page=30)) | * Work backwards from the order of installation when removing anything. Just crack them loose in reverse order, then back them off in reverse order. ((wedge of the XLFORUM http://xlforum.net/forums/showthread.php?t=1756724&page=30)) | ||
| + | Try and take pics, just for you, (although we'd like to see them too) before, during and after teardown. | ||
| ====== Possible Causes of Spun Cam Bushings ====== | ====== Possible Causes of Spun Cam Bushings ====== | ||
| - | + | On the cam bushings in either the cover or cases you have 3 different metals (brass/bronze/metallic) with different expansion rates so what really happens? ((rocketmangb of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/188092-cam-bushing-question-and-other-information-please/page2?t=2005347&page=2)) ((Hippysmack of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-bottom-end/188092-cam-bushing-question-and-other-information-please/page2?t=2005347&page=2)) \\ | |
| - | On the cam bushings in either the cover or cases you have 3 different metals (brass/bronze/metallic) with different expansion rates so what really happens? ((rocketmangb of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347&page=2)) ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347&page=2)) \\ | + | |
| As soon as there is initial movement of the bushing, the oil feed hole doesn't line up. \\ | As soon as there is initial movement of the bushing, the oil feed hole doesn't line up. \\ | ||
| - | After that the outside of the bushing is being oiled more than the inside of the bushing. ((A 4 liter V8 eater of the XLFORUM http://xlforum.net/forums/showthread.php?t=1756724&page=13)) \\ | + | After that the outside of the bushing is being oiled more than the inside of the bushing. ((A 4 liter V8 eater of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/163447-spun-2-outer-bushing-again/page13?t=1756724&page=13)) \\ |
| ===== Installation Errors ===== | ===== Installation Errors ===== | ||
| - | |||
| These items will begin a natural degradation of improper oiling and / or heat related failures: \\ | These items will begin a natural degradation of improper oiling and / or heat related failures: \\ | ||
| Line 62: | Line 69: | ||
| * The cast aluminum cam cover case being thinner than the bronze bushing may heat up and expand sooner, possibly loosening the fit between the case and the bushing? \\ The bushing is in intimate contact with the cover bore resulting in excellent heat transfer. So the parts remain at equal temps. | * The cast aluminum cam cover case being thinner than the bronze bushing may heat up and expand sooner, possibly loosening the fit between the case and the bushing? \\ The bushing is in intimate contact with the cover bore resulting in excellent heat transfer. So the parts remain at equal temps. | ||
| * Translation: The bushing is more likely to spin in the bore on a cold engine startup than hot due to thermal qualities. | * Translation: The bushing is more likely to spin in the bore on a cold engine startup than hot due to thermal qualities. | ||
| - | * **Bushings get too hot and stick to the cams then spin in the case**? | + | * **Bushings get too hot and stick to the cams then spin in the case**? \\ The cams are splash lubed. They don't get oiled from oil pump pressure (feed side). ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077485&page=24)) \\ You could see thru your inner cam bores into the crankcase if the flywheels were removed. In operation; \\ The inner bushings are fed from air/oil mist windage from the back and from gravity from the slot in the bushings that are suppose to all point North. \\ The outer bushings are fed from air/oil mist entering the back of the cam cover through holes in the bores. \\ In 92-up engines, there is a small hole in the oil galley (lifter feed) that squirts down on #2 cam (thrown about in cam chest). |
| * **Insufficient lubrication**. \\ | * **Insufficient lubrication**. \\ | ||
| + | * **Lugging the engine**. | ||
| + | * A Sportster is a higher revving engine than a Big Twin. \\ Trying to keep RPMs low to get that "Potato-Potato" sound puts more load on the engine with less oil flow to cool with and the oil pump delivers more oil as RPMs rise. \\ Basically you'd be asking the oil pump to deliver more oil at lower RPM than the now heating up engine can deliver = a poor oiling condition. | ||
| * **Oil contamination**. \\ Any of these items can cause enough contamination of the oil to create enough heat to ruin cam bearings / bushings. | * **Oil contamination**. \\ Any of these items can cause enough contamination of the oil to create enough heat to ruin cam bearings / bushings. | ||
| * Normal engine wear leaves metal particles in the oil. You may have seen gray or metallic sludge in the oil doing an oil change. \\ If left unchanged for too long, these metal particles add up and clog up orifices and / or sifts between bearings / bushings. | * Normal engine wear leaves metal particles in the oil. You may have seen gray or metallic sludge in the oil doing an oil change. \\ If left unchanged for too long, these metal particles add up and clog up orifices and / or sifts between bearings / bushings. | ||
| Line 84: | Line 93: | ||
| * Wetsumping and other oil system related issues, clogged oil lines etc. | * Wetsumping and other oil system related issues, clogged oil lines etc. | ||
| * Crankshaft Failure allowing metal grit to get splashed between the bushing and camshaft. | * Crankshaft Failure allowing metal grit to get splashed between the bushing and camshaft. | ||
| - | * **Sheared pinion shaft key under pinion gear allowing it to turn and change overall cam timing**? \\ This results in a valve slapping a piston and the force travels back to the cams knocking the shafts into a bushing and spinning it. | + | * **Sheared pinion shaft key at pinion gear allowing it to turn and change overall cam timing**? |
| - | * When the valve opens, pressure is exerted in 2 directions (cam to valve and valve to cam). ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077485&page=26)) \\ The valve opens due to that being the weakest point (sprung) when the lobe lifts. The cam has no springs. \\ The sudden jolt of the piston hitting the valve can transfer back down the path. \\ (and push the spinning cam's shaft against a bushing it's not suppose to be touching while spinning) \\ Thus catching and spinning the bushing (no oiling issues to seize the bushings) | + | * Assuming all four cams stay in time with each other and the pinion gear spins; \\ This results in the (now out of time) valves slapping 1 piston or both depending on how far the gear traveled. \\ And the force travels back to the cams knocking the shafts into a bushing and spinning it. \\ What happens to one cam happens to all once the clearance between the teeth mesh is taken up from being in a bind. \\ So one bent pushrod or piston slapping a valve can possibly spin all four cams bushings. |
| + | * The bushings are a press/interferance fit (not bolted or pinned). The camshafts turn in the center of the bushings while the engine is running (not touching the bushing). \\ When the valve opens, pressure is exerted in 2 directions (cam to valve and valve to cam). ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077485&page=26)) \\ The valve opens due to that being the weakest point (sprung) when the lobe lifts. The cam has no springs. \\ The sudden jolt of the piston hitting the valve can transfer back down the path. \\ (and push the spinning cam's shaft against a bushing it's not suppose to be touching while spinning) \\ Thus catching and spinning the bushing (no oiling issues to seize the bushings) | ||
| * **Repair**. When the bushings spin in the cases, they don't leave a perfectly round bore. As they spin, they rip/ream some of the bore I.D. and may move the bore center. \\ Finding that center with oversize bushings should be done by a qualified machine shop. | * **Repair**. When the bushings spin in the cases, they don't leave a perfectly round bore. As they spin, they rip/ream some of the bore I.D. and may move the bore center. \\ Finding that center with oversize bushings should be done by a qualified machine shop. | ||
| * Dark Horse Crankworks offers a replacement service for spun bushings. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347)) [[https://darkhorsecrankworks.com/|Click here for the link]]. \\ They can also upgrade them to bearings like the 4-speeds had. However, the cost of either service might approach the cost of a new set of cases. \\ Check with them and check with your dealer. New cases will be stamped with your VIN. \\ You literally have to turn in your old cases, or at least the portion of them that has the VIN, to buy new ones. | * Dark Horse Crankworks offers a replacement service for spun bushings. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347)) [[https://darkhorsecrankworks.com/|Click here for the link]]. \\ They can also upgrade them to bearings like the 4-speeds had. However, the cost of either service might approach the cost of a new set of cases. \\ Check with them and check with your dealer. New cases will be stamped with your VIN. \\ You literally have to turn in your old cases, or at least the portion of them that has the VIN, to buy new ones. | ||
| * Easter MC sells oversized cam bushings to replace bushing number (25598-91). ((RKN of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347&page=2)) \\ +.005" oversized bushing (A-25598-91+5). [[https://vtwin.parts/harley-davidson-indian-motorcycle-eastern-bushingcam-gear-crankcase(.005)-a-25598-915|Click here for the link]]. \\ +.001" oversized bushing (A-25598-91+1) [[https://vtwin.parts/index.php?_route_=supplier/eastern/new-products/harley-davidson-indian-motorcycle-eastern-new-product-a-25598-911|Click here for the link]]. | * Easter MC sells oversized cam bushings to replace bushing number (25598-91). ((RKN of the XLFORUM http://xlforum.net/forums/showthread.php?t=2005347&page=2)) \\ +.005" oversized bushing (A-25598-91+5). [[https://vtwin.parts/harley-davidson-indian-motorcycle-eastern-bushingcam-gear-crankcase(.005)-a-25598-915|Click here for the link]]. \\ +.001" oversized bushing (A-25598-91+1) [[https://vtwin.parts/index.php?_route_=supplier/eastern/new-products/harley-davidson-indian-motorcycle-eastern-new-product-a-25598-911|Click here for the link]]. | ||
| - | | Spun #2 Cam 2006 Cover Bushing. Heat coloring on front of cam. ((photos by drummerboy4as of the XLFORUM http://xlforum.net/forums/showthread.php?t=548748)) || | + | | Spun #2 outer cam bushing, 2006 cam cover. Heat coloring on front of cam. ((photos by drummerboy4as of the XLFORUM http://xlforum.net/forums/showthread.php?t=548748)) || |
| |{{:techtalk:ref:genmsr:2006_spun_cam_bushing_1_by_drummerboy4as.jpeg?direct&300|}}|{{:techtalk:ref:genmsr:2006_spun_cam_bushing_2_by_drummerboy4as.jpeg?direct&300|}}| | |{{:techtalk:ref:genmsr:2006_spun_cam_bushing_1_by_drummerboy4as.jpeg?direct&300|}}|{{:techtalk:ref:genmsr:2006_spun_cam_bushing_2_by_drummerboy4as.jpeg?direct&300|}}| | ||
| ====== Possible Causes of a Spun Pinion Shaft Gear ====== | ====== Possible Causes of a Spun Pinion Shaft Gear ====== | ||
| + | There is a bronze oil pump gear available which is considered an upgrade but that won't stop the key from shearing. \\ | ||
| + | Read more about the [[techtalk:evo:oil03#known_drive_gear_failure|oil pump drive gear failure and upgrade]] here in the Sportsterpedia. \\ | ||
| - | * **Pinion nut torque**. | + | * **Loose pinion shaft nut**. |
| * When installing the pinion nut, use Loctite red per the manual, and torque it to 70ft-lbs. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=5746883)) \\ It's pretty rare to have the gear fail in a stock Sportster. You typically only run into this issue after hop-up work. \\ The factory torque spec is 35-45 ft/lbs. which is too little torque for upgraded engines and often results in a sheared pinion key. | * When installing the pinion nut, use Loctite red per the manual, and torque it to 70ft-lbs. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=5746883)) \\ It's pretty rare to have the gear fail in a stock Sportster. You typically only run into this issue after hop-up work. \\ The factory torque spec is 35-45 ft/lbs. which is too little torque for upgraded engines and often results in a sheared pinion key. | ||
| + | * Per HD Tech Tip #19, the "T" key simply aligns the pinion shaft to the mark on the pinion gear for timing the cams. ((HD Tech Tip #19 dated June 1990)) \\ With the introduction of the one piece, right hand flywheel, the pinion shaft no longer has a taper. \\ Instead the oil pump drive gear and the pinion gear depend on clamp load to remain in position. | ||
| + | * In the pics below, the little nub of the key that protrudes from under the oil pump gear is the only portion of the key that engages the pinion gear. ((aswracing of the XLFORUM)) \\ That's why it shears so easily if the nut is loose. There just ain't much holding it besides the clamp force of the nut. \\ The clamp force from the nut holds the pump gear on, not the key. | ||
| + | * **Using heavy Valve Springs**. \\ | ||
| + | * Breaking the key is a very common issue particularly when heavy valve springs are used. \\ The force from the springs transfers thru the cams to the pinion gear and puts extra pressure on the pinion key. \\ And that force may be enough to break the key allowing the pinion gear to move. \\ The fix is Loctite red and 70ft-lbs instead of the factory specified 35-45ft-lbs. You won't have this issue again. ((http://hammerperf.com/ttxlcaminstall.shtml#pinionnut)) \\ The higher clamp force is needed to overcome the pressure of heavy springs. | ||
| + | |||
| + | |||
| + | | Pinion key location ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=2077485&page=22)) | Condition of key after gear spins ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=5746883)) |Pinion gear spun (app 90°), stopped and still turned \\ the cams from new location ((photo by npaisnel of the XLFORUM, edited by Hippysmack http://xlforum.net/forums/showthread.php?t=2077485&page=23))| | ||
| + | |{{:techtalk:evo:engmech:pinion_key_nub_by_aswracing.jpg?direct&300|}}| {{:techtalk:ref:genmsr:sheared_pinion_shaft_key_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:spun_pinion_gear_2_by_npaisnel.jpg?direct&300|}}| | ||
| + | \\ | ||
| + | * **Spotting a spun pinion gear with the cam cover off**. | ||
| + | * There is a keyway (slot) cut the width of the oil pump gear (underneath it, under one of it's teeth). \\ There is also a short slot (keyway) cut into the inner side of the pinion gear (not under it) and the slots in the two gears line up. \\ The timing mark on the pinion gear is lined up with the slots. So the timing mark on the pinion gear should line up with a tooth on the face of the oil pump gear. \\ If you hear noises or suspect damage in the gearcase, pull the cam cover and look a straight line back from the pinion gear's timing mark to oil pump drive gear. \\ If the pinion gear slot is facing a valley (between two teeth) on the pump gear, the pinion key (at least the part that holds the pinion gear) has sheared. \\ And the pinion gear has turned to some degree out of time with the crankshaft. | ||
| + | * This also brings concerns of bent pushrods from the cams getting out of time due to the spun pinion gear and a valve hitting a piston. | ||
| + | |||
| + | | 1988-up oil pump drive gear / pinion gear keyways. ((photo by npaisnel of the XLFORUM, labeled by Hippysmack http://xlforum.net/forums/showthread.php?t=2077485&page=26)) | | ||
| + | |{{:techtalk:evo:engmech:oil_pump-pinion_gear_keyways_by_npaisnel.jpg?direct&350|}}| | ||
| - | {{:techtalk:ref:genmsr:sheared_pinion_shaft_key_by_aswracing.jpg?direct&300|}} ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=5746883)) \\ | + | | Pinion gear slot aligned with pump gear face. ((photo by Hippysmack)) | Spun pinion gear. ((photos by npaisnel of the XLFORUM, labeled by Hippysmack http://xlforum.net/forums/showthread.php?t=2077485&page=24)) || |
| + | |{{:techtalk:evo:engmech:pinion_gear_-_shaft_alignment_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:genmsr:spun_pinion_gear_4_by_npaisnel.jpg?direct&300|}}|{{:techtalk:ref:genmsr:spun_pinion_gear_3_by_npaisnel.jpg?direct&300|}}| | ||
| ===== Affects of a Spun Pinion Shaft Gear ===== | ===== Affects of a Spun Pinion Shaft Gear ===== | ||
