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techtalk:ref:engmech04 [2020/07/28 22:35] hippysmack [Vacuum Pump for Reducing Crankcase Pressure] |
techtalk:ref:engmech04 [2020/09/21 21:11] hippysmack [Sub Documents] |
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**Cruise** (low load test): Typical RPM most riding takes place in (2500-3000 RPM). \\ | **Cruise** (low load test): Typical RPM most riding takes place in (2500-3000 RPM). \\ | ||
- | ===== Testing with a Slack Tube by bustert ===== | + | ===== Testing with a Slack Tube (Manometer) by bustert ===== |
==== Sub Documents ==== | ==== Sub Documents ==== | ||
* [[techtalk:ref:engmech04e|Building Your Own Slack Tube]] | * [[techtalk:ref:engmech04e|Building Your Own Slack Tube]] | ||
- | * [[techtalk:ref:engmech04f|Using / Diagnosing with a Manometer Slack Tube]] | + | * [[techtalk:ref:genmsr04#using_diagnosing_with_a_slack_tube_manometer|Using / Diagnosing with a Slack Tube (Manometer)]] |
* [[techtalk:ref:engmech04g|Slack tube testing on a 1998 1250S model]] | * [[techtalk:ref:engmech04g|Slack tube testing on a 1998 1250S model]] | ||
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Other factors are involved so results will vary. \\ | Other factors are involved so results will vary. \\ | ||
===== Why Oil Pukes Out the Air Cleaner ===== | ===== Why Oil Pukes Out the Air Cleaner ===== | ||
- | Wet sumping is a term usually used when oil spits out the breather vent / air cleaner. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5757523#post5757523)) \\ | + | Wet sumping is a term usually used when oil spits out the breather vent / air cleaner. ((Hippysmack of the XLFORUM http://xlforum.net/forums/showthread.php?p=5757523#post5757523)) \\ |
- | However, engine breathing and wet sumping are two different ideas. But they are tied together as much as air and water. \\ | + | However, engine breathing and wet sumping are two different ideas. But they are tied together as much as air and water. \\ See [[techtalk:ref:engmech04#wetsumping|Wet Sumping]] below. \\ |
- | See [[techtalk:ref:engmech04#wetsumping|Wet Sumping]] below. \\ | + | Oil puking and oil seepage out the air cleaner are different conditions. \\ |
+ | You'll know it if it pukes as there will be a good puddle of oil on the shop floor or gobs of oil running rearward of the A/C all over the bike. \\ | ||
+ | Oil seepage (or the oil filter getting saturated with oil over time) may be perfectly normal. \\ | ||
The real reason these things like to spit oil out the breather is because they're a common crankpin 45° design. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=110375&highlight=variable+volume#post110375)) \\ | The real reason these things like to spit oil out the breather is because they're a common crankpin 45° design. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?p=110375&highlight=variable+volume#post110375)) \\ | ||
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===== Aftermarket Breathers / PCV Valves ===== | ===== Aftermarket Breathers / PCV Valves ===== | ||
- | ==== Sub Documents ==== | ||
- | * [[techtalk:ref:engmech04a|Dissecting the Hayden KVP38 Crankcase Breather Valve]] | ||
- | * [[techtalk:ref:engmech04b|Frequently Asked Questions About the Hayden Krankvent]] | ||
- | |||
- | There is a product called a Krankvent that can be plumbed into the lower, 6 o’clock position as an alternative to a stock foo-foo valve. ((Hopper of the XLFORUM http://xlforum.net/forums/showthread.php?t=518948&highlight=cam+chest+breather)) \\ | ||
- | But they are not cheap. Automotive PCV valves are not really made to handle the revs or air volumes of a Harley. \\ | ||
- | While a car engine is bigger, it has one piston coming down while one goes up. \\ | ||
- | So there's not much change in internal crankcase volume, so not as much breathing to be done. \\ | ||
- | A Harley has two pistons and rods on one crankpin, so is one giant air compressor. \\ | ||
- | |||
- | Some guys have found that plumbing in a 77-78 foo-foo valve on the later model engines improves breathing. \\ | ||
- | |||
- | **Finding a better breather valve**: ((bunny32 of the XLFORUM http://xlforum.net/forums/showthread.php?t=15705&page=2)) \\ | ||
- | The breather valves that work best on crankcase breathers have several features: \\ | ||
- | * Low-inertia, i.e. they don't take more than a breath to open and close. | ||
- | * They operate at low pressures ~1-30psi. | ||
- | * They preferably have a floating type seal. | ||
- | * They should be transparent, so you can see if they block up with blowby, solids, bugs etc. | ||
- | * They should be easy to open and clean occasionally. | ||
- | * They should push-fit into your breather line. | ||
- | |||
- | Metal diaphragm valves with e.g. springs are hopeless. \\ | ||
- | Also avoid other types of valves designed to work at high pressures e.g. plumbing valves. \\ | ||
- | Avoid car PCV valves as they are metering as well as non-return valves and are unsuitable. \\ | ||
- | Automotive PCV valves are designed to let some air back in. \\ | ||
- | The ball and spring valves will not be able to work fast enough to keep all the air out. \\ | ||
- | When air is allowed to be drawn back into the engine, it creates a mass that must be compressed by the pistons on downstroke as it is being vented out. \\ | ||
- | This robs some power and will cause the engine to work harder (creating more internal heat at higher RPM). ((Deimus of the XLFORUM http://xlforum.net/forums/showthread.php?t=67658&page=18)) \\ | ||
- | |||
- | Aftermarket PCV's: ((electronbee of the XLFORUM http://xlforum.net/forums/showthread.php?t=72099&highlight=reed+valve&page=10)) \\ | ||
- | * Mercedes Benz P/N# 271-018-00-29 ~$13. | ||
- | * Reed type PCV valve. Fast acting. Used for their C 230 Kompressor engine. | ||
- | * Dims: 2-1/2" long by 1-1/8" with an I.D of 1/4". | ||
- | * McCaster Carr P/N# 4610K17 ~$6. | ||
- | * Umbrella valve. Vacuum check valve. | ||
- | * Autozone P/N# PCV1174 (PV272) ~$5. | ||
- | * Ball/spring based PCV valve. | ||
- | * Makes a clicking noise during operation. | ||
- | |||
- | | Here is a 2-stroke reed valve. ((photo by norseXL of the XLFORUM http://xlforum.net/forums/showthread.php?t=1386341&highlight=reed)) | | ||
- | |{{:techtalk:ref:engmech:reed_valve_by_norsexl.jpg?direct&300|}}| | ||
- | |||
- | | Mercedes Benz P/N# 271-018-00-29 ((photo by electronbee of the XLFORUM http://xlforum.net/forums/showthread.php?t=72099&highlight=reed+valve&page=10)) | Reed Valve ((photo by Bluto of the XLFORUM http://xlforum.net/forums/showthread.php?p=5761290#post5761290)) | Doherty Power Vent ((Photo by goblin_dust of the XLFORUM http://xlforum.net/forums/showthread.php?t=72099&highlight=wet+sumping&page=23)) | | ||
- | |{{:techtalk:ref:engmech:mercedes_benz_pcv_valve_by_electronbee.jpg?direct&300|}}|{{:techtalk:ref:engmech:reed_valve_by_bluto.jpg?direct&300|}}|{{:techtalk:ref:engmech:deimus_mod_2_by_goblin_dust.jpg?direct&300|}}| | ||
==== Regarding horsepower gains from different breathers ==== | ==== Regarding horsepower gains from different breathers ==== |