Differences

This shows you the differences between two versions of the page.

--- techtalk:ref:engmech04 [2019/08/13 17:22]
hippysmack [Head Vents vs Cam Chest Vent]
+++ techtalk:ref:engmech04 [2019/08/18 04:44]
hippysmack [Breather Catch Can Test For Oil Leaks Out the Vent]
@@ Line 299: / Line 299: @@
 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. \\
+====== 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 357: / Line 481: @@
 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 541: @@
 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. \\
+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 745: @@
 </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. \\
 Results of the testing showed that the test bike did perform as designed using breathers in the rocker boxes. \\
@@ Line 809: / Line 824: @@
 The scavenge inlet sees pressure but is isolated from the vacuum when the pistons go back up. \\
 </blockquote>
 ====== Wetsumping ======
 Click to read the full article on [[techtalk:ref:oil10#wet_sumping|wetsumping]] in the REF section of the Sportsterpedia. \\
@@ Line 1068: / Line 1085: @@
 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 ======

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