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techtalk:ref:engmech07n [2020/10/02 16:38] hippysmack created |
techtalk:ref:engmech07n [2020/10/07 22:50] hippysmack [Dyno testing using the timing plug location for an additional crankcase vent by aswracing] |
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In the stock configuration, the crankcase vents through a pair of "umbrella" valves, which are essentially check valves. \\ | In the stock configuration, the crankcase vents through a pair of "umbrella" valves, which are essentially check valves. \\ | ||
There is a slight air inlet into the motor from a tiny hole near the umbrella. ((Hippysmack)) \\ | There is a slight air inlet into the motor from a tiny hole near the umbrella. ((Hippysmack)) \\ | ||
- | It acts as both an oil drain for anything that gets past the umbrella and an air intake to keep negative pressure from getting too high. | + | It acts as both an oil drain for anything that gets past the umbrella and an air intake to keep negative pressure from getting too high. \\ |
The pistons come down the first time and the crankcase air is expelled with the air being forced out through the umbrella valves. \\ | The pistons come down the first time and the crankcase air is expelled with the air being forced out through the umbrella valves. \\ | ||
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Another surprise was just how easy it was to plug the hose with my finger, and how it felt when I did. \\ | 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. \\ | The pressure was not great. \\ | ||
+ | |||
+ | ====== Regarding horsepower gains from different breathers ====== | ||
+ | |||
+ | From aswracing on testing breather vents for HP gain: ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=75740&highlight=reed+valve&page=6)) \\ | ||
+ | <blockquote>Many years ago, I spent most of a day dyno testing breather check valves. \\ | ||
+ | I was writing for Battle2win magazine at the time and published my findings there. \\ | ||
+ | The article is here at Nightrider.com: [[http://www.nightrider.com/biketech/crankvent_test.htm|Do Crank Vents work?]] \\ | ||
+ | |||
+ | I spent several hours on the dyno testing whether or not various breather arrangements affected the power of a motor. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=20871)) \\ | ||
+ | Mainly it was a test of these breather check valve devices, but I also tested the recycling of the blowby versus venting to the atmosphere. \\ | ||
+ | |||
+ | {{:techtalk:ref:engmech:breather_valve_test_results_by_aswracing.gif?direct&700|}} ((chart by aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=20871&page=2)) \\ | ||
+ | |||
+ | The result labeled "kuryakyn" is the one that's recycling the blowby. \\ | ||
+ | So named because I used a kuryakyn adapter to send the blowby back into the intake tract. \\ | ||
+ | All the others are vented to the atmosphere. \\ | ||
+ | |||
+ | The bottom line was that none of them added a single iota of measurable horsepower, despite the grandiose claims of up to 7% from the manufacturers. \\ | ||
+ | The only thing I could get to show up on the dyno at all was the removal of the blowby from the intake tract.\\ | ||
+ | You can read all about the results in the Nightrider article above. \\ | ||
+ | One of the companies involved, ET products (maker of the Spyke Krank vent) took exception. \\ | ||
+ | I very carefully retested using their suggestions, but I got the exact same answer. \\ | ||
+ | </blockquote> | ||