| Author | Message | ||
     Ara |
Kevin: It's certainly the Occam's Razor approach! Anybody??? Jose? | ||
| Reepicheep |
I believe the breathers exhale AND inhale... so I would think contamination would be an issue if you don't have a filter on there. As for volume, the most I have seen is a teaspoon or so after 100 miles. Of that, I think a lot of it is gas and water. | ||
| Aaron |
Bill: how do they inhale past the umbrella valves? Doesn't the blowby create a net positive? | ||
| Rattler |
A quick breather system that works well & is cheap is to purchase the banjo bolts(hollow bolts with holes in the side of the bolt shank) from the HD Big Twins. It's the banjo bolts used on the tube crossover system sold as an accesory for BT's. They cost 5 bux each. I then took these with hollow fittings with an AN nipple pointing out 90 degrees & installed the banjo's in the fittings with the nipple pointing up! No oil ever comes out in this position, but the engine breathes good. One drawback will be a air pumping sound from the breathers at idle. You won't hear it any other time. This eleminated hoses routed down under the bike & filters, plus eleminates oil going back into the carb which contibutes to carbon build-up over time. I did this mod on a Sportster, but it should work the same on a Buell. You also would need the HyperCharger type CV carb bracket to secure the carb to the manifold. 23 bux from Drag Specialties. Dale A. | ||
| Reepicheep |
Aaron... I didn't say they DO, I said I BELIEVE they do, big difference  You have forgotton more about these engines then I will ever know, I'll take your word for it. Anyone ever put a checkvalve on these things and checked to see if there is ever a negative pressure situation? Bill "responding to breather threads AND oil threads... must looking for trouble today" | ||
| Mikej |
Kevinhern, See one of my posts on this thread, I did route my Ms'2 breather lines down with a filter on the end, and did get oil spray. Never seemed to affect my traction, but maybe I just got lucky. A previous owner routed my S2's breather line foreward up near the triple-trees with a filter on the end, and I do get some drippage, but not a lot on that bike. I'll be going to a catch-can on the S2 this winter (assuming Winter ever arrives here). | ||
| Aaron |
"Anyone ever put a checkvalve on these things and checked to see if there is ever a negative pressure situation?" Oh! Oh! Oh! (raising hand) ... Don and I did this. We used a cross fitting, fed a line to each head breather, a line to a check valve to the atmosphere, and a line to a pressure/vacuum gauge. Didn't see squat except a moving needle! Removing the check valve made no difference in the range of movement, either. YMMV. We also hooked up a vacuum pump. The dyno said no difference. And we even plugged the damn things. Again, the dyno said no difference. The *only* way we could get the damn breather system to change the dyno reading was to direct the blowby back into the carb, the way the factory does it. AW | ||
| Mikej |
"... to change the dyno reading was to direct the blowby back into the carb, the way the factory does it." And that gave a negative result to the dyno numbers, right? | ||
| Aaron |
Yup. | ||
| Sarodude |
Aaron- I don't at all dispute the breather into carb carb phenomenon robbing power. However I am curious - could it be some resonant effects causing the change? I know you're not exactly bored (though you MUST certainly be looking for things to do when the CO weather gets bad!) but it would be cool if SOMEONE could try some kind of contraption that would isolate blow by gasses and the pulses that accompany them... -Saro | ||
| Aaron |
Anything's possible, but it seems intuitive to me that feeding oily exhaust back into the intake tract would hurt power. And that's essentially what's coming out the breathers. | ||
| Sarodude |
Man, do I hate it when someone makes a good point... I realized much of my (mostly private) thoughts on the breather issue haven't considered the AMOUNT of blow-by that may require dealing with. Who had that baloon idea? -Saro | ||
| Ara |
Kevin had the balloon idea, and it's a good one. My S3 produces very, very little liquid out of the breathers, but it was enough to make a mess in the breadbox. I got tired of cleaning that up and wondered what that goop was doing to the carb, valves, and piston crowns. I'm certain that clean pure air produces more performance than air polluted by crankcase blow-by, but the mechanical health of my engine was my personal primary concern. Aaron, how big was the difference on the dnyo? Russ | ||
| Bluzm2 |
I wish the whole breather thing was simpler. I'm very tempted to go the Blast rocker box top route and be done with the whole thing. Seems a whole lot simpler than the whole catch can route. I have done the RB mods (drill and chamfer), it helped alot but I still get a bit of spooge after a hard ride. It would be nice to do away with it completely. Is there any downside to using the Blast box top? Brad | ||
| Ara |
Something just occurred to me concerning the drill and chamfer mod. If the liquids from the breather system are encouraged to drain back into the lubrication system, wouldn't this serve to increase the contamination of the motor oil? Russ | ||
| Aaron |
 "Kuryakyn" is the result that represents recycling the blowby, like the factory does it. So named because I used an adapter from Kuryakyn that sits between the carb and air cleaner and provides a breather hose connection. "Closed" is just that. The others are vented to the atmosphere, two of them through two different brands of magic valves, the other just open. The whole thing was kind of a let down after hearing all the hype about how you could make your motor run so much better with these devices. We just couldn't make the motor run better no matter what we did, even with a vacuum pump hooked up there. The only thing that mattered was removing the blowby from the intake, and anyone can do that for free. I later ran these tests on more bikes. Same result (warning: dyno chart overload). Brad: I agree ... and look at how they did the Blast, it's pretty slick, basically they use a long piece of hose for the catch can. You drain it right next to the oil tank drain. AW | ||
| Blake |
Ara: The moisture will still escape as it is in vapor form. The mod on the drain hole helps to eliminate excess/pooling of oil. | ||
| Ara |
Blake: I know that you've forgotten far more about these engines than I've yet learned. However it seems to me that the drain hole cannot know the difference between oil or other less desirable liquids. If the mod returns oil to the engine more readily by helping to eliminate excess/pooling of oil, it can't help but return other liquids to the engine more readily as well. As I wrote earlier, the liquid I get from my breathers is far too runny and thin to have much oil in it. Wouldn't I want that OUT of my engine? Russ | ||
| Blake |
Russ: During warm weather operation, water from combustion blow-by stays in vapor form (steam) at 212oF or more and escapes making its way through the crankcase and then rockerboxes as a gas to then quickly condense in the breather tubes/catch can. You should not see liquid water in a warm engine's rockerboxes. However, in cold weather, water can collect in the oil. That is why it is important to get the engine thoroughly heated or change the oil more often in the winter. Ice in oil passages is very bad news. As far as the larger holes go... Oil floats on water, so even with the small hole, IF there were liquid water in your rockerbox(es) (VERY doubtful) it would be the first to drain anyway. Zat make sense? | ||
| Ara |
Yes, Blake, thanks. Geeze, ice in oil passages - I never thought of that. Your point about the relative specific gravities of water and oil is well taken. You sure know your stuff, O Enlightened One! Russ | ||
| Ara |
Kevin: Did you ever do your balloon test??? Russ | ||
| Kevinhern |
Ara, No, I haven't because the bike has been traped at the dealership for a simple speedo failure warranty repair for a week and a half. I'm pretty upset with this. I almost purchased the sensor myself when it failed (1500 miles)just to avoid having to take it in and leave it for such a simple repair. But since it's under warranty, I thought I should let them do it. At least, there would be another confirmed speedo failure that Buell would have to deal with. They attempted to test the speedometer and the sensor and determined they were ok. They deceided it must be the wiring harness. So, I rode the bike over two weeks with no speedo while waiting for the wiring harness to arrive at the dealership. All the while, I had my doubts about their diagnosis. I even went back to the dealership during this two week period and politely mentioned the fact that these sensors regulary fail and asked if they were certain that the sensor was ok. They assured me they new what they were doing so I left. The harness finally arrived and I made arrangements to drop the bike off. They spent two days replacing the harness. I called for an update at the close of the week and they said that the harness didn't fix the problem. (SUPRISE!) I was pissed! I KNEW the harness was not the problem from the info I've gotten on this Buell site. They said they were waiting for another part. I asked, "what part is that?" They then had to admit it was the speedo sensor. So, ANOTHER week passes and I here nothing from the dealership. I call at the close of THIS week and they tell me the Buell tec has been in school all week. Unbelievable! I can't believe that any other tech couldn't pick up an allen wrench and install the speedo sensor. If I could just get my damn bike back I would be happy to buy the sensor myself and install it. So, I've been over a month without my speedometer, almost two weeks without my bike, and have made numerous trips to the dealership over this issue. If I would have just followed my gut feeling and purchased the part for $50 bucks myself and replaced it in 5 mins I wouldn't be dealing with all of this right now. Sorry, to bore all of you with this story but I needed to vent my frustrations. I realize this story should be moved over to the electrical section. So, Ara, I'm going to do the ballon experiment on the breather as soon as I get my bike back. However, I've purchased two small K&N crank breather filters that will fit on the end of a 3/8 full line and I intend to filter the breather lines to be on the safe side. I have the Buell Pro Series air filter and it has L-shaped breather bolts from the heads. I intend to turn them straight down and run two separate hoses behind the back side of the cam cover and attach two separate filters to the hoses right above the shock. This might puke more stuff under the bike than I'm comfortable with but I'm going to give it a try. I'll keep ya posted. | ||
| Kevinhern |
I do want to add the fact that I have purchased two motorcycles from this dealership and have received EXCELLENT service from them. However, I feel they dropped the ball with this issue. | ||
| Blake |
Kevin: While riding north on the Blue Ridge Parkway last year, I had my breather line routed down behind the cam cover as you are proposing, though I had combined the two lines via the SE fitting recommended by Bartels for use with their carbon fiber intake. So, I only had a single tube running straight down from just below the rear breather, rather than two as you are planning. After enduring the frustration of having four ignition fuses pop on me while riding, I heeded the "what has changed since the bike was running okay" philosophy and yanked the tube off the SE breather assy and tossed it into my tool kit saddle bag. I susequently never experienced another ignition fuse failure. The interesting thing about this anecdotal story is that the fuses all popped when wacking the throttle wide open on a hot day, which is when blowby would be the most severe. I initially supposed that if I had taken time to look at the location of the breather tube, I might have found it was blowing on an electrical connector and causing a short. But the area is open to the environment and rainwater! How could a little oil mist cause a short, when riding through torential downpours or spraying the bike down in a car wash never instigated such a problem? My guess... Maybe the hose was rubbing/impinging on an electrical connection pushing it to ground against the case? I dunno, it will be an enigma for me. You might be able to use a bit longer or shorter tube than I had and be okay. But if your bike just stops running and you find a popped ignition circuit fuse, you may want to re-route your breather lines. Blake | ||
| Kevinhern |
Blake. Thanks so much for the heads up. That is very interesting. I'll certainly use this info. when I'm trying to figure out where to route the hoses. I'll let you know if I have any problems. By the way, did the puke make a big mess under your bike when the breather line was under the engine? | ||
| Blake |
No. I had minimal pukage though. Besides, it was under the engine, so I never saw it.  | ||
| Kevinhern |
Ara. I got my bike back and did the ballon experiment this afternoon. Before I rerouted the breather hoses, I put a balloon on the end of each hose and started the engine. As I expected, the balloons instantly started inflating. However, I started to rev the engine and the balloons started DEFLATING! I didn't expect to see this. I didn't spend a lot of time with it because I had already made up my mind to attach K&N crank filters on the hoses anyway. So, to recap: Close the throttle and the ballons inflate, open the throttle and the ballons deflate. So, I guess this means the engine actually breathes IN and OUT. | ||
| Kevinhern |
I've been thinking a bit more about the balloon test. I stated in my post above that the balloon deflated when I rev'd the engine up. The balloon actually just got smaller but didn't deflate completely. The balloon actually held air the entire time the engine was running. It got bigger with the trottle closed and started getting smaller when the throttle was opened. So, it seems the crankcase was venting positive pressure the entire time. I think it simply produces LESS positive pressure (blow by) when the engine is rev'd up because the rings seal better as combustion pressure increases. Look forword to everyone else's take on this. | ||
| Aaron |
I think that's a good analysis. Run one of these motors with the timing plug removed sometime. You cannot believe how much air is getting inhaled and exhaled through that timing plug. But because our breathers employ an integral check valve, we don't see this massive in/out breathing on them. We only see the net result, which is zero from the constant changes in crankcase volume, plus a slight outflow because ring seal isn't perfect. Hence the two little fittings provide plenty of flow, even when teed into a single 3/8 hose. If it's sucking in the breathers, your umbrella valves aren't working, and if your umbrella valves don't work, the flow capability of the breathing system may well get overloaded. I still haven't figured out what these timing plug breathers bring to the party. Seems like if the umbrellas are working and the rings are reasonable, the volume out the breathers is mice nuts, and well below the capacity of the breathers. Putting a breather on the timing plug seems like a solution looking for a problem. AW | ||
| Blake |
Two factors to consider in thinking about your balloon test results. 1. At lower rpm, there is more time for blowby to escape (power stroke takes twice as long at 2000 rpm compared to 4000 rpm). 2. Blowby increases with increasing engine load; it is not surprising then that revving an engine under no load produces no blowby. Try the same experiment with the bike on a dyno in high gear and you will likely see your balloon go POP! |
