| Author | Message | |||||||||||||||||||||||||||
     M2me |
Wait! Before you kill it can anyone explain the role of a bad umbrella valve and oil puking from the breather. I've looked in the archives but couldn't find anything. This is from directparts.com, the people who make the Cure and Cure Vent Plus:
So they are also saying that a hardened umbrella vale will allow more oil in the vent chamber but they don't really explain why. | |||||||||||||||||||||||||||
| Aaron |
Well, in a common crankpin 45 degree motor, the crankcase's volume is constantly changing, right? The pistons go up, it gets bigger, the pistons go down, it gets smaller, etc. Without umbrella valves, what's going to happen at the breathers? To see for yourself, pull the timing plug off the crankcase and start the motor. You'll see a massive inhalation/exhalation cycle. You'll also get a face full of oil with every exhalation. The factory's solution to this is simple: put a check valve on there. Now it can't suck air in. And if it can't suck air in, then it's got nothing to blow out, either, right? Well, except that some air gets in, mainly stuff that gets past the rings. Blow-by. Voila, a huge reduction in the air passing through the breathers, and less air passing through the breathers means less oil being carried out. FYI, here's something that was posted a LONG time ago: "For those who have oil puking problems through the head breathers, Buell is encouraging us to make two modifications to the middle rocker box cover to cure this problem, or when the rocker box gaskets are replaced: (1) drill out the oil drain hole to 1/8" so that oil can drain more easily, and (2) chamfer 60 degrees the hole in which the umbrella valve sits. According to BMC, the new umbrella valves will not sit down fully (and seal off) because of their new design/material--chamfering the hole allows more of the stem of the umbrella valve to pull down into the hole and seal off better. According to Randell Hendricks, this fix has solved every instance of oil puking to which it has been applied. Bottom line: cheap and easy fix." | |||||||||||||||||||||||||||
| Blake |
Aaron, Thanks. | |||||||||||||||||||||||||||
| Aaron |
The biggest problem with the umbrella valves IMO is their location. Take a look at this setup:  This is a reed valve in the crankcase itself, in the S&S special application cases I use in my 100" race motor. I *believe* the idea here is to isolate the suction created by the rising pistons from the inlet to the oil pump, thus improving scavenging. Question: why does Buell put a reed valve between the crankcase and gearcase on the XB9? I mean, I know they say it reduces oil loss out the breathers, but how does it work? I dont't understand why that would be any more effective than a valve in the rocker box. Seems like they're both in the same path. They're isolating the gearcase and rocker boxes from the vacuum but it seems like the flow would be the same. And the main oil pump inlet is still going to see vacuum so I can't imagnie that;s why they did it. Blake? Anyone? | |||||||||||||||||||||||||||
| M2me |
Thanks, Aaron! That makes sense. By the way, I bought the Cure Vent Plus product. I haven't installed it yet (still too cold here in Minnesota to work on the bike). It is basically a vent extension with a check ball. The installation instructions say to put in new umbrella valves and to drill out the drain hole to 1/8". They don't mention chamfering the valve seat. I wonder if their Cure product (without the checkball) would do much good. Probably just replacing the umbrella valve, drilling the drain hole and chamfering the seat would be just as effective. The Cure Vent Plus has a checkball which, in theory, should reinforce the function of the umbrella valve. | |||||||||||||||||||||||||||
| Spiderman |
Nope i have the cure (no check ball) and it isn't as good as i planned. Then again i havent chamfered the valves. I also put in new pistons too. | |||||||||||||||||||||||||||
| Notsip |
This is not a ploy to advertise and sell a product. I don't need to use this site or any other site to sell products. I am not asking for any business from this. All I am doing is stating what our past tests and experiences is what causes spewage and what we have done to fix the problem. Apparently as a new member you don't value anything that they have to say or appreciate any information that they have to share. It was very expensive to this type of testing and I have shared it with you at NO CHARGE!! FREE!!!. I wanted to cover everything that we have found in the top end and their components before the questions (GRILLING) started. Without making the statements first you have no way to tear it apart. It is very easy for somone to take potshots at every remark but what hard (REAL WORLD) data do you have to back it up? I will answer your question as I can and to the best of my ability. I know that there are several of you that are engineers and love to disect the information to nth degree. I also know that some of you that enjoy crusifying someones information. That is very evident in other posts. Blake; BTW your diagram is incorrect again. Look at it again and refigure where the thrust and non-thrust sides of the cylinder are and then change you numbers. I must be fairly correct in what I have posted because it look's like you will be doing everything you can to prove it wrong and if you can't you will probably dump this thread as you stated above. On your earlier diagram about the leverage and the amount of stress that is applied, if you don't think that there is much stress applied to the front cylinder just call Don Tilley and ask him how many front aluminum chrome bore cylinders he has broken in half on his Buell Road Race bike and why they broke. I think this will change your theory about the stress. I know that it is going to very difficult to compare theory to facts, it's like comparing an apple to an orange, and although theory is great the results do differ in real life application. The information that I provided is real life application, so before you try to completely crusify me and my tests, why don't you do all of your theory data and then repeat the same test that I have done on your engine and then you can compare your theory data to the real life data. I will offer you the opportunity to bring your engine to our facility and in your presence we can perform the same test on it as we have done. Again NO CHARGE!! FREE!! That way we can compare apples to apples. What do you think about doing that? I'm up to it are you? If this doesn't get deleted by the moderator I will try to answer your questions. If you would please list them in numerical order it will make it easier to answer them. By the way, if there is a simple fix available and listed in your archives, how come there is so many people still complaining about spewage and why didn't someone send them to the archives earlier or come up with a remedy? Appears that I am the only one that has offered any constructive information. Thanks' Notsip | |||||||||||||||||||||||||||
| Blake |
Aaron, Some brainstorming type thoughts... By reducing the volume of air in constant communication with the crankcase the valve may be eliminating resonant flow problems (similar to reversion pulses in the exhaust) that might exacerbate transport of oil mist to the breather port. Reducing the magnitude of pressure fluctuations in the gearcase and rockerboxes might benefit more consistent lubrication there. Where does the oil tank vent line get its feed? The gearcase? | |||||||||||||||||||||||||||
| Aesquire |
Myself, I like the variety of solutions I've seen here. This is a tiny hop up that offers broad customization possibilities. These bikes may NEED a solution more than a generic 4 banger, but all the 4 strokes I've owned needed somewhere for exhaust blow by to go. | |||||||||||||||||||||||||||
| Blake |
Notsip, My diagram reflects the data you provided, unless you are contending that the "thrust" side of the cylinders is the front instead of the rear. That would be incorrect. Here's how I understand it...  Thrust side is where piston is "thrust" against cylinder wall due to kick load imparted by connecting rod. Notsip's Temperature Data
 I already numbered some questions. Didn't seem to help. Here they are again... 1. Is that data for aluminum or iron cylinders? 2. Do you have data for the other? 3. What were the conditions under which the temperatures were produced? 4. What kind of performance (peak RWHP @ rpm) did the engine produce on the dyno? 5. What comprised the engine, stock or high performance parts, bore, stroke...? 6. Was this a dyno simulation or an actual on the road/track test? 7. What engine lubricant was used? | |||||||||||||||||||||||||||
| Rick_A |
Mikej...my breather setup is a simple T that vents up to the open air and the other branch goes down to the "catch tube." Notsip...I've never heard of front cylinder breakage problems. It can't be a common problem. There are people that impart higher loads on chassis and suspension than racers ever will (aside from crashes)...look at Craig Jones...he's not snappin' cylinders. If that were the case...a few of my moments of stupidity should've torn my shiznit right off! So does Tilley use cast iron cylinders? Last I heard they were using nikasil lined like the majority of the serious race efforts. On umbrella valves...I was considering the "factory" cure to avoid the puking problem from creeping up...but the umbrellas that came with my Cometic kit fit perfect. | |||||||||||||||||||||||||||
| Blake |
Notsip, More rhetoric I see... I shall continue to respond, why I'm not sure... "This is not a ploy to advertise and sell a product. I don't need to use this site or any other site to sell products. I am not asking for any business from this. All I am doing is stating what our past tests and experiences is what causes spewage and what we have done to fix the problem." You could have saved a lot of time and trouble by simply saying that you have found that installing a set of Axtell cast iron cylinders and special piston oiling jets solved the breather oil spewage in your engines. "Apparently as a new member you don't value anything that they have to say or appreciate any information that they have to share." Not true, but half of the stuff you offered was not valid, all of it was simply opinion without any evidence offered to support it, at least until you finally offered the cylinder temperature data, and even with that we have absolutely no idea what the test entailed or what kind of engine was involved. Can you not see why that would lead us to be skeptical. We are not a bunch of desk jockeys here. Show some respect, and you might earn it in return. Continually repeating your mantra of "theory" versus the "real world" tells me nothing of the validity of your statement. "It was very expensive to this type of testing and I have shared it with you at NO CHARGE!! FREE!!!." I wouldn't pay five cents for the test results you've shared here. Like I and others have said, test results are meaningless unless the test parameters, procedure, and configuration are also known. You have not shared any of that information here. I still don't know what material comprised your test cylinders. You speak in such vague generalities. I cannot read your mind, you have to tell me the details. "I wanted to cover everything that we have found in the top end and their components before the questions (GRILLING) started." WTF are you talking about??!! In your first lengthy post on the topic YOU specifically ASKED everyone to post questions...
"Without making the statements first you have no way to tear it apart. It is very easy for somone to take potshots at every remark but what hard (REAL WORLD) data do you have to back it up?" Read my posts. Engineering is real, whether you care admit it or not. You think automobiles and airplanes are cobbled together and optimized in "the real world" without engineering? Take a couple years and design me a stealth bomber in your beloved "real world" devoid of engineering expertise. "I will answer your question as I can and to the best of my ability." That would be nice. It appears that you have some interesting and pertinent test data. We'd like to understand what it really means. "I know that there are several of you that are engineers and love to disect the information to nth degree." Yep, engineers are like that. We strive to understand the science behind "real world" observations. "I also know that some of you that enjoy crusifying someones information. That is very evident in other posts." Not at all. I personally however have little tolerance for someone who posing as an expert, offers assumption and conjecture as hard fact. Blake; BTW your diagram is incorrect again. Look at it again and refigure where the thrust and non-thrust sides of the cylinder are and then change you numbers." See above. Where am I wrong? I've asked you before to be specific in identifying and correcting any inaccuracies you find in my statements. You still have not identified where specifically my "swingarm analogy" is flawed, or even what you mean by "swingarm analogy." "I must be fairly correct in what I have posted because it look's like you will be doing everything you can to prove it wrong and if you can't you will probably dump this thread as you stated above." I've said before that you may be correct in your assertion that an iron cylinder is better for preventing blowby. My personal "real life", "real world" experience however is that all aluminum cylinders perform incredibly well in that respect, even in a 100RWHP engine being flogged for hundreds of miles on the race track in sweltering Texas Summer heat. That is as real world as you can get. I've even measured the rear cylinder head temperature at over 500oF at the exhaust port. So my experience doesn't agree with your assertions, thus I'm questioning your opinions wrt aluminum cases being overstressed and aluminum cylinders being weak and easily distorting. I don't see it. You've offered little to no evidence of any kind (real world or valid theory) to convince me otherwise. Yes, cast iron is stiffer than aluminum, by a factor of almost three. It is also a poor conductor of heat, by a factor of almost three. From what I know and even from what data you've posted, the major factor in cylinder distortion is the differential temperatures. I don't see iron having a clear advantage in that respect since it will become MUCH hotter and less uniform in temperature than an aluminum cylinder. That is not theory, it is simple engineering fact. "On your earlier diagram about the leverage and the amount of stress that is applied, if you don't think that there is much stress applied to the front cylinder just call Don Tilley and ask him how many front aluminum chrome bore cylinders he has broken in half on his Buell Road Race bike and why they broke. I think this will change your theory about the stress." I thought Tilley's used nicasil plated cylinders. If you would look again at my diagram, you might see that I have included a significant load acting on the front cylinder head. I never claimed it was not subjected to stresses. You say Tilley broke the front cylinders on their race bikes? That should be easy to confirm... Buckinfubba!!!! Please confirm! ![:]](http://www.badweatherbikers.com/buell/clipart/proud.gif) "I know that it is going to very difficult to compare theory to facts, it's like comparing an apple to an orange, and although theory is great the results do differ in real life application." There you go again. If theory fails to produce accurate predictions of actual performance, the theory is simply wrong or inadequately comprehensive. "The information that I provided is real life application, so before you try to completely crusify me and my tests, why don't you do all of your theory data and then repeat the same test that I have done on your engine and then you can compare your theory data to the real life data." WTF are you talking about? Was your "figured" cylinder stud preload theory or real data? I have no desire to "crucify" anyone. I simply demand accountability and integrity in any technical statement offered in this forum. It is very telling that not once have you admitted any error in your statements even though some have been shown to be inaccurate. "I will offer you the opportunity to bring your engine to our facility and in your presence we can perform the same test on it as we have done. Again NO CHARGE!! FREE!! That way we can compare apples to apples. What do you think about doing that? I'm up to it are you?" I live in Texas. My engine runs GREAT. My engine doesn't suffer from oily breather pukage. What do you think? What would be the purpose? "If this doesn't get deleted by the moderator I will try to answer your questions." Please do. "If you would please list them in numerical order it will make it easier to answer them." Done. "By the way, if there is a simple fix available and listed in your archives, how come there is so many people still complaining about spewage and why didn't someone send them to the archives earlier or come up with a remedy?" To be honest I had forgotten all about that. I don't think very many sufferers of oily pukage have implemented the recommended fix. I do know that some who have tried it have met with success. I don't think all have though. "Appears that I am the only one that has offered any constructive information." Sorry you feel that way. I've expended a ridiculous amount of effort in this discussion. I'd like to think my contributions are constructive. Maybe if you would go back and answer my questions (not just the 7 above, all of them), you could offer additional constructive information. Blake (living "real life" in the "real world" for as long as I can remember... at least until putting this friggin web site up) PS: I hear we are hot on Osama's tail. Just a dose of reality to put this discussion into perspective. It's all good if it is about an engine bolted between two wheels, right?  | |||||||||||||||||||||||||||
| Peter |
Please don't anyone kill this thread. For what it's worth, I've tried a few different types of breather hose set-ups. Two hoses into a 'T' piece and a single hose to under the cases. Leaked a bit. Two separate hoses to single filters under the cases. Almost no leakage. Drilled the drain hole and chamfered the umbrella hole. Fitted a crossover tube (ala Screaming Eagle) with banjo bolts and a single hose from the rear cylinder. Major oil spewage. Fitted a single filter with inlets at either end, mounted under the carb bowl with short hoses and banjo bolt fittings from the head. Zero leakage. All on the same '00 M2. I am now using the same single filter under the carb set-up on the turbo S1, with stock HD cylinders. Zero leakage. PPiA | |||||||||||||||||||||||||||
| Mikej |
Rick_A, Thanks, I was just curious. Breather routing is one of the things I look at on various bikes. PPiA, Any chance you have a pic of that setup handy that you might be able to post? Thank you too. Sounds like a simple clean efficient setup. | |||||||||||||||||||||||||||
| Aaron |
Notsip: if having your information challenged upsets you that much, you might want to reconsider your participation here. People here aren't likely to quit doing it just because you hold yourself out as knowledgeable, particularly when the information you offer is riddled with things we know to be inaccurate as well as claims that you can't substantiate. If, however, you want to hang around, learn a few things, offer a few things, give and take and not assume that everyone else is stupid, I'm sure you could make a positive contribution and ultimately make this a better place. There are some smart people here, personally I've learned a TON from them, and I try to give back a little from time to time as well. Works for me, you might give it a try. | |||||||||||||||||||||||||||
| Mikej |
"I'm sure you could make a positive contribution and ultimately make this a better place." I'll second that.  Stick around. | |||||||||||||||||||||||||||
| Aesquire |
Peter, Thanks. That list would indicate restriction is BAD. (and I learn something new, 4 cyl bikes have but 1 breather hose usually ) | |||||||||||||||||||||||||||
| Sarodude |
Notsip- I'll echo the "stick around" sentiment as well. The stuff you've provided is certainly interesting - though it's provided without any context. The analogy might be me telling you of a 300hp motorcycle engine - then providing NO further details. No displacement, no engine configuration, nothing regarding normal aspiration or forced induction... You obviously have a lot of valuable experience. On this board, if you give, ye shall receive. Of course, if you give what is perceived as bullshit, you will receive what would be perceived as a fish beating.  Relax. Learn the ropes. Remember your first race? Pretty intimidating, eh? Mine was. -Saro | |||||||||||||||||||||||||||
| Peter |
Mikej, Yep.   PPiA | |||||||||||||||||||||||||||
| Mikej |
Thanks! | |||||||||||||||||||||||||||
| Reepicheep |
Peter... That does not leak? Really! I have a very similar setup, but with a loop around the bottom and a second loop around the top (where that same filter sits). The bottom loop makes a sort of catch can. Interesting, I might have to give it a try. I don't get a lot of spooge, but it would be nice to have something I don't have to drain. | |||||||||||||||||||||||||||
| M2me |
I don't know nothing about thrust and such, but the diagram that Blake posted with the temperatures from notsip satisfies my common sense. Coolest on the front of the front cylinder, hotter in the "valley", hottest on the front of the rear cylinder, cooler on the rear of the rear cylinder but not as cool as the front of the front cylinder. Having said all that, my common sense is skeptical about the actual numbers. Look at the top of the rear cylinder. Is there really an almost 250 degree difference across maybe a 4" area near the combustion chamber? My common sense tells me there would be temperature differences, but 250 degrees? I'm skeptical. | |||||||||||||||||||||||||||
| Blake |
M2me, I suspect Notsip's results are for a cast iron cylinder and/or for a very highly stressed state of operation. I'm sure he'll clarify that tonight. | |||||||||||||||||||||||||||
| Hootowl |
"Question: why does Buell put a reed valve between the crankcase and gearcase on the XB9? I mean, I know they say it reduces oil loss out the breathers, but how does it work? I dont't understand why that would be any more effective than a valve in the rocker box. Seems like they're both in the same path. They're isolating the gearcase and rocker boxes from the vacuum but it seems like the flow would be the same. And the main oil pump inlet is still going to see vacuum so I can't imagnie that;s why they did it. Blake? Anyone?" Aaron, Perhaps to reduce the amount of air that exits the head? Less air blowing through picks up less oil which blows out less oil? | |||||||||||||||||||||||||||
| Aaron |
I guess I don't see how moving the check valve down to the cam box reduces the amount of air exiting the head. The exiting air should be equivalent to the amount of blow-by in both cases, no? | |||||||||||||||||||||||||||
| Blake |
Aaron, Where does the exhausting crankcase vapor enter the gearcase? | |||||||||||||||||||||||||||
| Aaron |
Right next to the cams. | |||||||||||||||||||||||||||
| Hootowl |
Maybe the checkvalve in the case is more effective than the umbrella valves in the rocker boxes. | |||||||||||||||||||||||||||
| Aaron |
I'm sure it is, I'm just trying to understand why. | |||||||||||||||||||||||||||
| Hootowl |
Larger surface area/higher flow capacity combined with a more positive closure? |
