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techtalk:ref:engmech04 [2019/08/13 17:22] hippysmack [Head Vents vs Cam Chest Vent] |
techtalk:ref:engmech04 [2019/10/11 19:54] hippysmack [Vacuum Pressure] |
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{{:techtalk:ref:engmech:86-90_sportster_positive_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) {{:techtalk:ref:engmech:86-90_sportster_negative_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) | {{:techtalk:ref:engmech:86-90_sportster_positive_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) {{:techtalk:ref:engmech:86-90_sportster_negative_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) | ||
- | 91-03 models with head breather vents: \\ | + | 91-97 models with head breather vents: \\ |
- | {{:techtalk:ref:engmech:91-03_sportster_positive_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) {{:techtalk:ref:engmech:91-03_sportster_negative_crankcase_pressure_by_hippysmack.jpg?direct&300|}} ((drawing by Hippysmack)) | + | {{:techtalk:ref:engmech:91-97_sportster_positive_crankcase_pressure_by_hippysmack.jpg?direct&300|}} {{:techtalk:ref:engmech:91-97_sportster_negative_crankcase_pressure_by_hippysmack.jpg?direct&300|}} \\ |
+ | |||
+ | 98-03 models with head breather vents: \\ | ||
+ | {{:techtalk:ref:engmech:98-03_sportster_positive_crankcase_pressure_by_hippysmack.jpg?direct&300|}} {{:techtalk:ref:engmech:98-03_sportster_negative_crankcase_pressure_by_hippysmack.jpg?direct&300|}} \\ | ||
04 and Up models with head breather vents: \\ | 04 and Up models with head breather vents: \\ | ||
Line 299: | Line 302: | ||
Listen for where the air is coming out during the test: intake port, exhaust port, or breathers. \\ | Listen for where the air is coming out during the test: intake port, exhaust port, or breathers. \\ | ||
See also [[techtalk:ref:svcproc21#cylinder_leak-down_test|Performing a cylinder leak down test]] in the REF section of the Sportsterpedia. \\ | See also [[techtalk:ref:svcproc21#cylinder_leak-down_test|Performing a cylinder leak down test]] in the REF section of the Sportsterpedia. \\ | ||
+ | |||
+ | ====== Crankcase Pressure Testing ====== | ||
+ | ===== Dyno testing using the timing plug location for an additional crankcase vent by aswracing ===== | ||
+ | |||
+ | The following is to share some dyno testing by aswracing of using the timing plug location for an additional crankcase vent. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4)) \\ | ||
+ | |||
+ | First, a little background. \\ | ||
+ | In the stock configuration, the crankcase vents through a pair of "umbrella" valves, which are essentially check valves. \\ | ||
+ | There is no air inlet into the motor. \\ | ||
+ | The pistons come down the first time and the crankcase air is expelled, the air is forced out through the umbrella valves. \\ | ||
+ | |||
+ | But when the pistons go back up, the umbrella valves block the inflow of air, causing a slight vacuum in the crankcase. \\ | ||
+ | The next time the pistons come down, crankcase pressure will return to atmospheric at BDC before the upstroke. \\ | ||
+ | If no air is allowed into the motor, the crankcase will cycle between a vacuum (pistons up) and atmospheric (pistons down). \\ | ||
+ | |||
+ | However, some air is actually allowed to enter, primarily in the form of blow-by that escapes the combustion chamber past the rings. \\ | ||
+ | Therefore, in the stock design, there is a small net outflow. \\ | ||
+ | The amount will vary with the condition of the motor. | ||
+ | |||
+ | Properly functioning umbrella valves therefore serve the purpose of significantly reducing the breather capacity requirement while also minimizing crankcase pressure. \\ | ||
+ | Excessive airflow & oil discharge through the breathers can be caused by malfunctioning umbrella valves that are allowing air into the motor. \\ | ||
+ | |||
+ | For this test, an additional vent was added at the timing plug hole. \\ | ||
+ | No check valve was installed on this vent. \\ | ||
+ | Therefore, the crankcase is being allowed to pull in air as the pistons go up. \\ | ||
+ | **This fundamentally changes the engine's venting design**. \\ | ||
+ | |||
+ | Some people feel that allowing the engine to both inhale and exhale in this manner reduces crankcase pressure. \\ | ||
+ | Several people cite a "seat of the pants" improvement in performance. \\ | ||
+ | The purpose of this test was to determine if there actually is a performance improvement from this change to the venting system. \\ | ||
+ | |||
+ | The fitting arrangement used is in the pic below. \\ | ||
+ | The threads on the flare match the timing plug hole threads. \\ | ||
+ | There are two fittings threaded together and app. two feet of 3/8" I.D. hose was attached to the hose barb. | ||
+ | |||
+ | |3/8" flare to 1/4" FPT fitting \\ with a 1/4" MPT to 3/8" hose barb. ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Fitting and hose as installed on the bike.((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Test bike (near stock 1999 M2). ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))| | ||
+ | |{{:techtalk:ref:engmech:timing_plug_adapter_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:testing_cc_pressure_1_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:testing_cc_pressure_2_by_aswracing.jpg?direct&300|}}| | ||
+ | |||
+ | Lots and lots of dyno pulls were performed in each configuration and the configuration was switched back and forth a few times. \\ | ||
+ | Dyno results are not 100% repeatable, and as such, below is a range of results for each configuration, as well as a comparison of best pulls. \\ | ||
+ | Click on a chart to enlarge: \\ | ||
+ | |||
+ | |10 best pulls from the stock configuration. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|10 best pulls from timing plug vent configuration. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Best stock pull and the best timing plug vent pull. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))| | ||
+ | |{{:techtalk:ref:engmech:dyno_and_breathing_1_by_aswracing.gif?direct&300|}}|{{:techtalk:ref:engmech:dyno_and_breathing_2_by_aswracing.gif?direct&300|}}|{{:techtalk:ref:engmech:dyno_and_breathing_3_by_aswracing.gif?direct&300|}}| | ||
+ | |||
+ | As you can see, the difference is within the repeatability of the measurement. \\ | ||
+ | If a person *had* to declare a winner, the results with the stock setup would seem to have a little edge. \\ | ||
+ | (both in the "best" results and just looking at the average of the 10 best results) \\ | ||
+ | But I'd be careful doing that, you could be looking at normal variation. \\ | ||
+ | |||
+ | **Observations**: \\ | ||
+ | I was surprised at how little air movement there was at the end of the hose. \\ | ||
+ | When a motor is started with nothing screwed into the timing plug, there's a massive inhalation and exhalation evident. \\ | ||
+ | But apparently, necking it down to a 3/8" hole and connecting 2 feet of hose adds a pretty significant restriction. \\ | ||
+ | Air flow was nowhere near what I expected. \\ | ||
+ | Unfortunately, getting a 7/16" or 1/2" hose into that area would be problematic, space is tight. \\ | ||
+ | Plus, a fitting with the correct thread and a 7/16" or 1/2" hole may not be available. \\ | ||
+ | |||
+ | Another surprise was just how easy it was to plug the hose with my finger, and how it felt when I did. \\ | ||
+ | The pressure was not great. \\ | ||
+ | |||
+ | ===== Breather System Air Volume Test by DK Custom ===== | ||
+ | The full article is on the DK Custom web site. [[http://www.dkcustomproducts.com/breather-system-flow-testing-results-video.htm]] \\ | ||
+ | This testing was done to find out: \\ | ||
+ | How much air was passed out the breather vents at idle, under a load, at cruising speeds and on throttle let-off. \\ | ||
+ | And also the differences between a variety of HD engines, along with engines that had been hopped up with cams and or higher compression pistons/heads. \\ | ||
+ | |||
+ | In this test, air was captured and measured as to how much water volume was displaced in a fixed period of time. \\ | ||
+ | Taking the liquid ounce displacement, you can convert that to Cubic Feet Per Minute (CFM) | ||
+ | There are 957.50649350649 U.S. fluid oz. in 1 Cubic Foot. \\ | ||
+ | |||
+ | Results: \\ | ||
+ | Sportsters move the least amount of air through the breathers. | ||
+ | Twin Cams move the most amount of air through the breathers, with little difference between air cooled and Twin Cooled. \\ | ||
+ | Milwaukee-Eights move more air than Sportsters, but little more than half as much as the Twin Cams through the breathers. \\ | ||
+ | Even more surprising is the least amount of air is moved on all bikes while at cruising RPM. \\ | ||
+ | |||
+ | The only way to get a significant amount of air to move through the Sportsters was to get the RPM up around redline. \\ | ||
+ | (and that crankcase pressure was probably because the valves were beginning to float) | ||
+ | The most amount of air is moved through the breathers at idle, during hard acceleration and during deceleration. \\ | ||
+ | A visual of this can be seen in this video: [[https://www.youtube.com/watch?v=Kio4DEuOpCU|DK Custom Breather System Air Volume Testing of Harley-Davidsons ]] \\ | ||
+ | |||
+ | The actual numbers are in the chart below. \\ | ||
+ | (engines warmed up / oil level on midway mark of dipstick before testing) \\ | ||
+ | |||
+ | | **DK Customs Products Breather Report** (from different throttle / riding conditions) ||||| | ||
+ | |**Bike tested**|**CFM \\ (idle)**|**CFM \\ (cruise)**|**CFM \\ (hard acceleration)**|**CFM \\ (deceleration)**| | ||
+ | |**Air Cooled Twin Cam (103)**|.2172|.08|.1952|.2504| | ||
+ | |**Twin Cooled Twin Cam (103)**|.2548|.0972|.2231|.2874| | ||
+ | |**M8 Air Cooled (107)**|.1211|.06|.1059|.1127| | ||
+ | |**Sportster (1250 with high compression)**|.0125|.0125|.0125|.0125| | ||
+ | |:::|At redline (6200 RPM) with no load (.3326 CFM)|||| | ||
+ | |**Sportster (1200)**|.0626|.0626|.0626|.0626| | ||
+ | |||
+ | **CFM**: Cubic Feet per Minute. \\ | ||
+ | **Deceleration Test**: Measured by chopping the throttle to 0% with the clutch in. \\ | ||
+ | **Cruise** (low load test): Typical RPM most riding takes place in (2500-3000 RPM). \\ | ||
+ | |||
+ | ===== Testing with a Slack Tube by bustert ===== | ||
+ | |||
+ | Testing was done from the timing plug hole and then from the oil tank with a slack tube on a 2001 XL1200S (with no load) by bustert of the XLFORUM. ((http://xlforum.net/forums/showthread.php?p=5767694#post5767694)) \\ | ||
+ | |||
+ | On the left (from timing hole plug), the engine begins at high vacuum (green liquid line on scales in pics below). \\ | ||
+ | Notice that there is a transition to a positive pressure above the 5k mark. \\ | ||
+ | On the right (from oil tank), there is an equalization on positive and negative at 5K. \\ | ||
+ | |||
+ | One could speculate anything from over-running vent capacity to time factors. \\ | ||
+ | The numbers are subjective to ambient temps and elevation. \\ | ||
+ | However, we could use it as a tool to determine engine wear like they do on a diesel engine. \\ | ||
+ | All-in-all, the subject engine operated as HD intended (within the intended most used rpm range). \\ | ||
+ | |||
+ | The results are in (inches of water) and you can convert to psig but remember, you have to add both sides. \\ | ||
+ | So a 15 on one side with a 15 on the other would be 30". \\ | ||
+ | |||
+ | |Slack Tube testing from timing hole plug. ((photos by bustert of the XLFORUM http://xlforum.net/forums/showthread.php?p=5767694#post5767694))||Slack Tube testing from oil tank|| | ||
+ | |1000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_1_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_1.1_by_bustert.jpg?direct&300|}}|1000 \\ RPM| | ||
+ | |2000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_2_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_2_by_bustert.jpg?direct&300|}}|2000 \\ RPM| | ||
+ | |3000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_3_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_3_by_bustert.jpg?direct&300|}}|3000 \\ RPM| | ||
+ | |4000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_4_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_4.2_by_bustert.jpg?direct&300|}}|4000 \\ RPM| | ||
+ | |5000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_5_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_5_by_bustert.jpg?direct&300|}}|5000 \\ RPM| | ||
+ | |6000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_6_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_6_by_bustert.jpg?direct&300|}}|6000 \\ RPM| | ||
+ | |||
+ | |||
+ | The testing showed that the test bike acted as intended with head breathers (venting through lines bypassing the A/C to atmosphere). \\ | ||
Line 342: | Line 469: | ||
|{{:techtalk:ref:engmech:86-90_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:engmech:91_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}| | |{{:techtalk:ref:engmech:86-90_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:engmech:91_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}| | ||
- | | 92-03 engine breathing paths. ((drawing by Hippysmack)) | 04 and Up engine breathing paths. ((drawing by Hippysmack)) | | + | | 92-97 engine breathing paths. ((drawing by Hippysmack)) | 98-03 engine breathing paths. ((drawing by Hippysmack)) | 04 and up engine breathing paths. ((drawing by Hippysmack)) | |
- | |{{:techtalk:ref:engmech:92-03_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:engmech:04_and_up_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}| | + | |{{:techtalk:ref:oil:92-97_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:oil:98-03_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:oil:04_and_up_sportster_engine_breathing_by_hippysmack.jpg?direct&300|}}| |
| Testing CC pressure on the dyno. ((photo by Jörgen http://xlforum.net/forums/showthread.php?t=75740&page=9)) | | | Testing CC pressure on the dyno. ((photo by Jörgen http://xlforum.net/forums/showthread.php?t=75740&page=9)) | | ||
Line 357: | Line 483: | ||
In the right application they can not be beat but you better have your ducks in a row. \\ | In the right application they can not be beat but you better have your ducks in a row. \\ | ||
+ | **Buell crankcase breathing**: \\ | ||
+ | | This is a Buell XBRR with reed valves through the cam chest wall. ((photos by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=829935)) || | ||
+ | |{{:techtalk:ref:engmech:reed_valves_1_on_buell_xbrr_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:reed_valves_2_on_buell_xbrr_by_aswracing.jpg?direct&300|}}| | ||
Line 415: | Line 543: | ||
So to keep oil out of the A/C, means keeping engine breathing And wet sumping in balance. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5757523#post5757523)) \\ | So to keep oil out of the A/C, means keeping engine breathing And wet sumping in balance. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5757523#post5757523)) \\ | ||
+ | ===== Breather Catch Can Test For Oil Leaks Out the Vent ===== | ||
+ | A test was done by XLFORUM member cjburr. Test apparatus and results are below. ((cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=13)) \\ | ||
+ | This testing was done to help diagnose an oil leak that couldn't be seen or otherwise detected. \\ | ||
+ | However, this may be a good exercise if you are concerned about how much oil you may be losing from the crankcase puking. \\ | ||
+ | It should show what, how much and when oil accumulates in the hose / catch can. \\ | ||
+ | The length / size of tubing will change crankcase pressure to an extent so the results may not reflect exactly what's going on inside your engine. \\ | ||
+ | |||
+ | The vent to air cleaner was inspected and then removed for testing. The factory system routes the breathers to the front of the carb. \\ | ||
+ | There was no evidence of the amount of oil that was being lost in the intake tract. \\ | ||
+ | With the Forcewinder A/C removed, there was no evidence of oil. | ||
+ | A homemade catch can with a vent hole and a clear tube was installed to inspect while riding. \\ | ||
+ | |||
+ | | A/C removed. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=13)) || Homemade catch can. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=13)) | | ||
+ | |{{:techtalk:ref:engmech:breather_catch_can_test_1_by_cjburr.jpg?direct&300|}}|{{:techtalk:ref:engmech:breather_catch_can_test_2_by_cjburr.jpg?direct&300|}}|{{:techtalk:ref:engmech:breather_catch_can_test_3_by_cjburr.jpg?direct&300|}}| | ||
+ | |||
+ | The A/C was re-installed with the venting ran to the catch can. \\ | ||
+ | The oil tank was filled to just under half way up the stick with SYN3. \\ | ||
+ | The bike was ridden hard (10 miles of city driving then 50 miles of elevated speeds). \\ | ||
+ | RPM was ran up to 6000 in 5th (8 times) and up to 100 MPH for 2 miles twice. \\ | ||
+ | Total miles run were 75 and all but 20 miles of that were at 80 MPH or more. \\ | ||
+ | The only thing that showed up in the tube running to the catch can was just some moisture but no oil. \\ | ||
+ | | The catch can was clean but 1/4 quart of oil had been lost as viewed from the dipstick. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=13)) ||| | ||
+ | |{{:techtalk:ref:engmech:breather_catch_can_test_4_by_cjburr.jpg?direct&300|}}| {{:techtalk:ref:engmech:breather_catch_can_test_5_by_cjburr.jpg?direct&300|}}|{{:techtalk:ref:engmech:breather_catch_can_test_6_by_cjburr.jpg?direct&200|}}| | ||
Line 597: | Line 748: | ||
</blockquote> | </blockquote> | ||
- | + | ===== Head Vents vs Cam Chest Vent ===== | |
- | ====== Crankcase Pressure Testing ====== | + | |
- | ===== Dyno testing using the timing plug location for an additional crankcase vent by aswracing ===== | + | |
- | + | ||
- | The following is to share some dyno testing by aswracing of using the timing plug location for an additional crankcase vent. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4)) \\ | + | |
- | + | ||
- | First, a little background. \\ | + | |
- | In the stock configuration, the crankcase vents through a pair of "umbrella" valves, which are essentially check valves. \\ | + | |
- | There is no air inlet into the motor. \\ | + | |
- | The pistons come down the first time and the crankcase air is expelled, the air is forced out through the umbrella valves. \\ | + | |
- | + | ||
- | But when the pistons go back up, the umbrella valves block the inflow of air, causing a slight vacuum in the crankcase. \\ | + | |
- | The next time the pistons come down, crankcase pressure will return to atmospheric at BDC before the upstroke. \\ | + | |
- | If no air is allowed into the motor, the crankcase will cycle between a vacuum (pistons up) and atmospheric (pistons down). \\ | + | |
- | + | ||
- | However, some air is actually allowed to enter, primarily in the form of blow-by that escapes the combustion chamber past the rings. \\ | + | |
- | Therefore, in the stock design, there is a small net outflow. \\ | + | |
- | The amount will vary with the condition of the motor. | + | |
- | + | ||
- | Properly functioning umbrella valves therefore serve the purpose of significantly reducing the breather capacity requirement while also minimizing crankcase pressure. \\ | + | |
- | Excessive airflow & oil discharge through the breathers can be caused by malfunctioning umbrella valves that are allowing air into the motor. \\ | + | |
- | + | ||
- | For this test, an additional vent was added at the timing plug hole. \\ | + | |
- | No check valve was installed on this vent. \\ | + | |
- | Therefore, the crankcase is being allowed to pull in air as the pistons go up. \\ | + | |
- | **This fundamentally changes the engine's venting design**. \\ | + | |
- | + | ||
- | Some people feel that allowing the engine to both inhale and exhale in this manner reduces crankcase pressure. \\ | + | |
- | Several people cite a "seat of the pants" improvement in performance. \\ | + | |
- | The purpose of this test was to determine if there actually is a performance improvement from this change to the venting system. \\ | + | |
- | + | ||
- | The fitting arrangement used is in the pic below. \\ | + | |
- | The threads on the flare match the timing plug hole threads. \\ | + | |
- | There are two fittings threaded together and app. two feet of 3/8" I.D. hose was attached to the hose barb. | + | |
- | + | ||
- | |3/8" flare to 1/4" FPT fitting \\ with a 1/4" MPT to 3/8" hose barb. ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Fitting and hose as installed on the bike.((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Test bike (near stock 1999 M2). ((photo by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))| | + | |
- | |{{:techtalk:ref:engmech:timing_plug_adapter_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:testing_cc_pressure_1_by_aswracing.jpg?direct&300|}}|{{:techtalk:ref:engmech:testing_cc_pressure_2_by_aswracing.jpg?direct&300|}}| | + | |
- | + | ||
- | Lots and lots of dyno pulls were performed in each configuration and the configuration was switched back and forth a few times. \\ | + | |
- | Dyno results are not 100% repeatable, and as such, below is a range of results for each configuration, as well as a comparison of best pulls. \\ | + | |
- | Click on a chart to enlarge: \\ | + | |
- | + | ||
- | |10 best pulls from the stock configuration. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|10 best pulls from timing plug vent configuration. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))|Best stock pull and the best timing plug vent pull. ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4))| | + | |
- | |{{:techtalk:ref:engmech:dyno_and_breathing_1_by_aswracing.gif?direct&300|}}|{{:techtalk:ref:engmech:dyno_and_breathing_2_by_aswracing.gif?direct&300|}}|{{:techtalk:ref:engmech:dyno_and_breathing_3_by_aswracing.gif?direct&300|}}| | + | |
- | + | ||
- | As you can see, the difference is within the repeatability of the measurement. \\ | + | |
- | If a person *had* to declare a winner, the results with the stock setup would seem to have a little edge. \\ | + | |
- | (both in the "best" results and just looking at the average of the 10 best results) \\ | + | |
- | But I'd be careful doing that, you could be looking at normal variation. \\ | + | |
- | + | ||
- | **Observations**: \\ | + | |
- | I was surprised at how little air movement there was at the end of the hose. \\ | + | |
- | When a motor is started with nothing screwed into the timing plug, there's a massive inhalation and exhalation evident. \\ | + | |
- | But apparently, necking it down to a 3/8" hole and connecting 2 feet of hose adds a pretty significant restriction. \\ | + | |
- | Air flow was nowhere near what I expected. \\ | + | |
- | Unfortunately, getting a 7/16" or 1/2" hose into that area would be problematic, space is tight. \\ | + | |
- | Plus, a fitting with the correct thread and a 7/16" or 1/2" hole may not be available. \\ | + | |
- | + | ||
- | Another surprise was just how easy it was to plug the hose with my finger, and how it felt when I did. \\ | + | |
- | The pressure was not great. \\ | + | |
- | + | ||
- | ===== Breather System Air Volume Test by DK Custom ===== | + | |
- | The full article is on the DK Custom web site. [[http://www.dkcustomproducts.com/breather-system-flow-testing-results-video.htm]] \\ | + | |
- | This testing was done to find out: \\ | + | |
- | How much air was passed out the breather vents at idle, under a load, at cruising speeds and on throttle let-off. \\ | + | |
- | And also the differences between a variety of HD engines, along with engines that had been hopped up with cams and or higher compression pistons/heads. \\ | + | |
- | + | ||
- | In this test, air was captured and measured as to how much water volume was displaced in a fixed period of time. \\ | + | |
- | Taking the liquid ounce displacement, you can convert that to Cubic Feet Per Minute (CFM) | + | |
- | There are 957.50649350649 U.S. fluid oz. in 1 Cubic Foot. \\ | + | |
- | + | ||
- | Results: \\ | + | |
- | Sportsters move the least amount of air through the breathers. | + | |
- | Twin Cams move the most amount of air through the breathers, with little difference between air cooled and Twin Cooled. \\ | + | |
- | Milwaukee-Eights move more air than Sportsters, but little more than half as much as the Twin Cams through the breathers. \\ | + | |
- | Even more surprising is the least amount of air is moved on all bikes while at cruising RPM. \\ | + | |
- | + | ||
- | The only way to get a significant amount of air to move through the Sportsters was to get the RPM up around redline. \\ | + | |
- | (and that crankcase pressure was probably because the valves were beginning to float) | + | |
- | The most amount of air is moved through the breathers at idle, during hard acceleration and during deceleration. \\ | + | |
- | A visual of this can be seen in this video: [[https://www.youtube.com/watch?v=Kio4DEuOpCU|DK Custom Breather System Air Volume Testing of Harley-Davidsons ]] \\ | + | |
- | + | ||
- | The actual numbers are in the chart below. \\ | + | |
- | (engines warmed up / oil level on midway mark of dipstick before testing) \\ | + | |
- | + | ||
- | | **DK Customs Products Breather Report** (from different throttle / riding conditions) ||||| | + | |
- | |**Bike tested**|**CFM \\ (idle)**|**CFM \\ (cruise)**|**CFM \\ (hard acceleration)**|**CFM \\ (deceleration)**| | + | |
- | |**Air Cooled Twin Cam (103)**|.2172|.08|.1952|.2504| | + | |
- | |**Twin Cooled Twin Cam (103)**|.2548|.0972|.2231|.2874| | + | |
- | |**M8 Air Cooled (107)**|.1211|.06|.1059|.1127| | + | |
- | |**Sportster (1250 with high compression)**|.0125|.0125|.0125|.0125| | + | |
- | |:::|At redline (6200 RPM) with no load (.3326 CFM)|||| | + | |
- | |**Sportster (1200)**|.0626|.0626|.0626|.0626| | + | |
- | + | ||
- | **CFM**: Cubic Feet per Minute. \\ | + | |
- | **Deceleration Test**: Measured by chopping the throttle to 0% with the clutch in. \\ | + | |
- | **Cruise** (low load test): Typical RPM most riding takes place in (2500-3000 RPM). \\ | + | |
- | + | ||
- | ===== Testing with a Slack Tube by bustert ===== | + | |
- | + | ||
- | Testing was done from the timing plug hole and then from the oil tank with a slack tube on a 2001 XL1200S (with no load) by bustert of the XLFORUM. ((http://xlforum.net/forums/showthread.php?p=5767694#post5767694)) \\ | + | |
- | + | ||
- | On the left (from timing hole plug), the engine begins at high vacuum (green liquid line on scales in pics below). \\ | + | |
- | Notice that there is a transition to a positive pressure above the 5k mark. \\ | + | |
- | On the right (from oil tank), there is an equalization on positive and negative at 5K. \\ | + | |
- | + | ||
- | One could speculate anything from over-running vent capacity to time factors. \\ | + | |
- | The numbers are subjective to ambient temps and elevation. \\ | + | |
- | However, we could use it as a tool to determine engine wear like they do on a diesel engine. \\ | + | |
- | All-in-all, the subject engine operated as HD intended (within the intended most used rpm range). \\ | + | |
- | + | ||
- | The results are in (inches of water) and you can convert to psig but remember, you have to add both sides. \\ | + | |
- | So a 15 on one side with a 15 on the other would be 30". \\ | + | |
- | + | ||
- | |Slack Tube testing from timing hole plug. ((photos by bustert of the XLFORUM http://xlforum.net/forums/showthread.php?p=5767694#post5767694))||Slack Tube testing from oil tank|| | + | |
- | |1000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_1_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_1.1_by_bustert.jpg?direct&300|}}|1000 \\ RPM| | + | |
- | |2000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_2_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_2_by_bustert.jpg?direct&300|}}|2000 \\ RPM| | + | |
- | |3000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_3_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_3_by_bustert.jpg?direct&300|}}|3000 \\ RPM| | + | |
- | |4000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_4_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_4.2_by_bustert.jpg?direct&300|}}|4000 \\ RPM| | + | |
- | |5000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_5_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_5_by_bustert.jpg?direct&300|}}|5000 \\ RPM| | + | |
- | |6000 \\ RPM|{{:techtalk:ref:engmech:checking_cc_pressure_at_timing_hole_plug_6_by_bustert.jpg?direct&300|}}|{{:techtalk:ref:engmech:checking_cc_pressure_at_oil_tank_6_by_bustert.jpg?direct&300|}}|6000 \\ RPM| | + | |
- | + | ||
- | + | ||
- | The testing showed that the test bike acted as intended with head breathers (venting through lines bypassing the A/C to atmosphere). \\ | + | |
- | + | ||
- | ===== Air Leaks ===== | + | |
- | The breathing system is designed for a one-way valve venting system. \\ | + | |
- | Air goes out but doesn't come back in. \\ | + | |
- | Air leaks (into the engine) will increase positive pressure and air / oil density = oil puking out the breathers. \\ | + | |
- | Some potential air leak areas are in the pic below. \\ | + | |
- | If these areas allow air to be pulled in the engine on upstroke, the added air will compound any other existing breathing problems. \\ | + | |
- | {{:techtalk:ref:engmech:potential_cc_pressure_leaks_at_the_rocker_box_by_daggar_rider_labeled_by_hippysmack.jpg?direct&300|}} ((photo by dagger rider of the XLFORUM )) | + | |
- | + | ||
- | ====== Head Vents vs Cam Chest Vent ====== | + | |
CC pressure (while venting thru the heads) was [[techtalk:ref:engmech04#head_vents_vs_cam_chest_vent|tested with a slack tube]] as in above. \\ | CC pressure (while venting thru the heads) was [[techtalk:ref:engmech04#head_vents_vs_cam_chest_vent|tested with a slack tube]] as in above. \\ | ||
Results of the testing showed that the test bike did perform as designed using breathers in the rocker boxes. \\ | Results of the testing showed that the test bike did perform as designed using breathers in the rocker boxes. \\ | ||
Line 773: | Line 791: | ||
Oil was introduced into the head with a with a turkey baster. \\ | Oil was introduced into the head with a with a turkey baster. \\ | ||
(which is probably a higher volume of oil than it normally sees from the splash oiling) \\ | (which is probably a higher volume of oil than it normally sees from the splash oiling) \\ | ||
+ | However, if the drains were plugged, oil would overfill to the point of spewing oil at the seams and submerge the seals. ((cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=33)) \\ | ||
| Head ready for testing. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) | Oil poured in and draining. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) |Oil level at the intake valve when it starts to drain to \\ the exhaust side. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) | | | Head ready for testing. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) | Oil poured in and draining. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) |Oil level at the intake valve when it starts to drain to \\ the exhaust side. ((photo by cjburr of the XLFORUM http://xlforum.net/forums/showthread.php?t=53769&highlight=valve+guide&page=31)) | | ||
Line 809: | Line 828: | ||
The scavenge inlet sees pressure but is isolated from the vacuum when the pistons go back up. \\ | The scavenge inlet sees pressure but is isolated from the vacuum when the pistons go back up. \\ | ||
</blockquote> | </blockquote> | ||
+ | |||
+ | |||
====== Wetsumping ====== | ====== Wetsumping ====== | ||
Click to read the full article on [[techtalk:ref:oil10#wet_sumping|wetsumping]] in the REF section of the Sportsterpedia. \\ | Click to read the full article on [[techtalk:ref:oil10#wet_sumping|wetsumping]] in the REF section of the Sportsterpedia. \\ | ||
Line 1068: | Line 1089: | ||
A slightly negative (to atmospheric) pressure in the tank facilitates vaporization of the condensate. \\ | A slightly negative (to atmospheric) pressure in the tank facilitates vaporization of the condensate. \\ | ||
+ | ====== Air Leaks ====== | ||
+ | The breathing system is designed for a one-way valve venting system. \\ | ||
+ | Air goes out but doesn't come back in. \\ | ||
+ | Air leaks (into the engine) will increase positive pressure and air / oil density = oil puking out the breathers. \\ | ||
+ | Some potential air leak areas are in the pic below. \\ | ||
+ | If these areas allow air to be pulled in the engine on upstroke, the added air will compound any other existing breathing problems. \\ | ||
+ | {{:techtalk:ref:engmech:potential_cc_pressure_leaks_at_the_rocker_box_by_daggar_rider_labeled_by_hippysmack.jpg?direct&300|}} ((photo by dagger rider of the XLFORUM )) | ||
====== Vacuum Pump for Reducing Crankcase Pressure ====== | ====== Vacuum Pump for Reducing Crankcase Pressure ====== |