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techtalk:ref:engmech05 [2020/10/06 21:25] hippysmack [Sub Documents] |
techtalk:ref:engmech05 [2022/01/15 23:35] hippysmack [Vent Outlet Above vs Below the Head Vents] |
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| * [[techtalk:ref:engmech05i|79-85 Breather Vent Mod - Adding a Secondary Vent Hose at 6:00 Position]] | * [[techtalk:ref:engmech05i|79-85 Breather Vent Mod - Adding a Secondary Vent Hose at 6:00 Position]] | ||
| * [[techtalk:ref:engmech05j|Aftermarket Breather Valves]] | * [[techtalk:ref:engmech05j|Aftermarket Breather Valves]] | ||
| + | * [[techtalk:ref:engmech05k|Installing "Slobber Stoppers" (1991-1993 Models)]] | ||
| + | * **Related articles in the Sportsterpedia**. | ||
| + | * [[techtalk:ref:engmech04k|Breather Valves (1957-Up)]] (list of breather valve changes) | ||
| + | * [[techtalk:ref:engmech05|Breather Venting / Relocation]] (list of breathing mods and aftermarket breathers) | ||
| + | * [[techtalk:ref:engmech04l|Head Vents vs Cam Chest Vent]] | ||
| + | * [[techtalk:ref:oil10#refoiling_lubrication|Wet Sumping]] | ||
| + | * [[techtalk:ref:engmech04m|Why Oil Pukes Out the Breather]] | ||
| + | |||
| ==== Aftermarket engine breathers and breathing mods in general ==== | ==== Aftermarket engine breathers and breathing mods in general ==== | ||
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| * 1990-prior breather valves (although obsoleted at the MoCo) are available online at times. \\ Sometimes you just have to wait and search to find them. \\ NOS valves can sometimes be found at dealerships but you'll have to contact them and ask. \\ (sometimes a phone call or in person will get better responses than emails). | * 1990-prior breather valves (although obsoleted at the MoCo) are available online at times. \\ Sometimes you just have to wait and search to find them. \\ NOS valves can sometimes be found at dealerships but you'll have to contact them and ask. \\ (sometimes a phone call or in person will get better responses than emails). | ||
| * 1977-up engines all use one way breather valves although exact construction and venting changed over the years. \\ 1977-1990 engines all vented from the cam cover. \\ So an external motorcycle one way breather valve (that can be plumbed sufficiently) can be installed externally in the same place. \\ 1977-up engines also all begin making full vacuum starting from when the second piston begins it's upstroke motion. \\ So any external motorcycle one way breather valve (that can be plumbed sufficiently) will work on 1977-up Sportsters. \\ It is important to note that while using an external breather valve, the internal valve should be removed. \\ Leaving the old valve inside will only create more restriction to the air moving out of the engine. | * 1977-up engines all use one way breather valves although exact construction and venting changed over the years. \\ 1977-1990 engines all vented from the cam cover. \\ So an external motorcycle one way breather valve (that can be plumbed sufficiently) can be installed externally in the same place. \\ 1977-up engines also all begin making full vacuum starting from when the second piston begins it's upstroke motion. \\ So any external motorcycle one way breather valve (that can be plumbed sufficiently) will work on 1977-up Sportsters. \\ It is important to note that while using an external breather valve, the internal valve should be removed. \\ Leaving the old valve inside will only create more restriction to the air moving out of the engine. | ||
| + | - **There is no sensible reason to change air cleaners or engine breathing just because that's someone else did**. | ||
| + | * If your goal is simply to change the overall appearance, by all means, make it your own. \\ But understand that sometimes you can help or hurt the breathing system by what changes you make and all engines are different. \\ You can test the crankcase pressure to find out what your engine is doing or needs so you'll know where to go from there. | ||
| - **One advantage of venting to atmosphere is cleaner combustion (and cleaner pistons)**. | - **One advantage of venting to atmosphere is cleaner combustion (and cleaner pistons)**. | ||
| * There is also a case against improper installation of external vent(s). \\ There are many aftermarket and homemade breather vent relocation mods available to move the vents out of the air cleaner. \\ However, depending on how you route the vent lines, you can cause emulsified oil accumulation in them. \\ Emulsified oil will just build up in the tubes until it all comes out. And it could also alter engine breathing if it doesn't come out. | * There is also a case against improper installation of external vent(s). \\ There are many aftermarket and homemade breather vent relocation mods available to move the vents out of the air cleaner. \\ However, depending on how you route the vent lines, you can cause emulsified oil accumulation in them. \\ Emulsified oil will just build up in the tubes until it all comes out. And it could also alter engine breathing if it doesn't come out. | ||
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| * Testing was done however to prove whether any breather vent in particular could make extra horsepower. \\ See comments by aswracing below on venting mods to obtain more horsepower: ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=75740&highlight=reed+valve&page=6)) | * Testing was done however to prove whether any breather vent in particular could make extra horsepower. \\ See comments by aswracing below on venting mods to obtain more horsepower: ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=75740&highlight=reed+valve&page=6)) | ||
| * I've induced scavenging issues mostly from using gapless rings. But not from venting mods. \\ However, I've dyno tested venting mods until I'm blue in the face and never found a single horsepower there. \\ (except for pulling the blow by out of the intake tract, which is good for a small across the board improvement) \\ S&S cases have no scavenging issues due to the strategic placement of the reed valve (in the sump). \\ The scavenge inlet sees pressure but is isolated from the vacuum when the pistons go back up. \\ In addition to the above, I also did a bunch of testing of the aftermarket breather check valves from Spyke and Hayden. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4)) \\ (and even did some experiments with vacuum pumps and the like) Did some magazine articles here and there at the time. \\ The motor was remarkably insensitive to anything I did with the breathers. \\ Like I said, the only thing I could get to show up on the Dyno sheet at all was the removing of the blow-by from the intake tract. | * I've induced scavenging issues mostly from using gapless rings. But not from venting mods. \\ However, I've dyno tested venting mods until I'm blue in the face and never found a single horsepower there. \\ (except for pulling the blow by out of the intake tract, which is good for a small across the board improvement) \\ S&S cases have no scavenging issues due to the strategic placement of the reed valve (in the sump). \\ The scavenge inlet sees pressure but is isolated from the vacuum when the pistons go back up. \\ In addition to the above, I also did a bunch of testing of the aftermarket breather check valves from Spyke and Hayden. ((aswracing of the XLFORUM http://xlforum.net/forums/showthread.php?t=1946516&page=4)) \\ (and even did some experiments with vacuum pumps and the like) Did some magazine articles here and there at the time. \\ The motor was remarkably insensitive to anything I did with the breathers. \\ Like I said, the only thing I could get to show up on the Dyno sheet at all was the removing of the blow-by from the intake tract. | ||
| + | - **Stage 1 or higher air cleaner changes makes OEM breather venting impossible**. | ||
| + | * It is still possible to keep the venting into the air cleaner when upgrading OEM air cleaners. \\ You may have to get creative with plumbing or fabrication in some instances however. | ||
| + | * You may also want to take advantage of some of the mods listed in the sub documents at the top of this page. \\ Again changing the breathing system can have it's downfalls and should only be done to improve the breathing system. \\ Testing the internal air pressure after performing breather mods will tell you if the mods helped or hurt the system. | ||
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| {{:techtalk:ref:engmech:clogged_breather_filter_by_60gunner.jpg?direct&300|}} ((photo by 60Gunner of the XLFORUM http://xlforum.net/forums/showthread.php?t=2074059&page=5)) {{:techtalk:ref:engmech:05_breather_mod_2_by_socal1200R_annotated_by_hippysmack.jpg?direct&300|}} ((photo by socal1200r of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=30844)) | {{:techtalk:ref:engmech:clogged_breather_filter_by_60gunner.jpg?direct&300|}} ((photo by 60Gunner of the XLFORUM http://xlforum.net/forums/showthread.php?t=2074059&page=5)) {{:techtalk:ref:engmech:05_breather_mod_2_by_socal1200R_annotated_by_hippysmack.jpg?direct&300|}} ((photo by socal1200r of the XLFORUM, annotated by Hippysmack http://xlforum.net/forums/showthread.php?t=30844)) | ||
| - | ====== Aftermarket Breather 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. \\ | ||
| - | |||
| - | **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 Breather Valves for Harley's: \\ | ||
| - | * Sifton Crankcase Breather ((https://www.ebay.com/itm/SIFTON-CASE-BREATHER-VENT-PCV-VALVE-HARLEY-EVO-SHOVELHEAD-PANHEAD-TWINCAM-KRANK/253213372444?epid=1665559744&hash=item3af4b1701c:g:F4cAAOSwzrxUuDhJ)) \\ This appears to be a cheaper version of the Hayden Crankvent also with an umbrella valve installed inside. \\ It is, however, a one time use part as it cannot be taken apart to replace the umbrella valve. | ||
| - | |||
| - | 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. | ||
| - | |||
| - | |||
| - | |Hayden KVP38 breather valve, used with the \\ [[techtalk:ref:engmech05d|Deimus Mod]] (cam chest breather conversion). ((photo by 60Gunner of the XLFORUM http://xlforum.net/forums/showthread.php?p=5763918#post5763918))| Hayden breather opened up. ((photos by leucadiaGuit of the XLFORUM http://xlforum.net/forums/showthread.php?t=2004869 cropped by Hippysmack)) || | ||
| - | |{{:techtalk:ref:engmech:deimus_mod_8_by_60gunner.jpg?direct&300|}}|{{:techtalk:ref:engmech:hayden_krankvent_3_by_leucadiaguit_-_cropped.jpg?direct&300|}}|{{:techtalk:ref:engmech:hayden_krankvent_2_by_leucadiaguit_-_cropped.jpg?direct&300|}}| | ||
| - | |||
| - | |Doherty Power Vents with the line routed up then \\ down and attached to the bottom of the frame. ((photo by RIORoosen of the XLFORUM http://xlforum.net/forums/showthread.php?t=146084&page=18))| 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:breather_mod_by_rioroosen.jpg?direct&300|}}|{{:techtalk:ref:engmech:deimus_mod_2_by_goblin_dust.jpg?direct&300|}}| | ||
| - | |||
| - | |||
| - | | Here is a 2-stroke reed valve. ((photo by norseXL of the XLFORUM http://xlforum.net/forums/showthread.php?t=1386341&highlight=reed)) | Reed Valve ((photo by Bluto of the XLFORUM http://xlforum.net/forums/showthread.php?p=5761290#post5761290)) | | ||
| - | |{{:techtalk:ref:engmech:reed_valve_by_norsexl.jpg?direct&300|}}|{{:techtalk:ref:engmech:reed_valve_by_bluto.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)) | | ||
| - | |{{:techtalk:ref:engmech:mercedes_benz_pcv_valve_by_electronbee.jpg?direct&300|}}| | ||
| ====== Homemade Breather Valves ====== | ====== Homemade Breather Valves ====== | ||
