---------------------------------------------------------- JabiruEngine-List Digest Archive --- Total Messages Posted Sat 03/17/12: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:34 AM - Re: valve problem (FLYaDIVE) 2. 09:31 AM - 3300 First Run Oil Question (AZFlyer) 3. 12:26 PM - Re: valve problem (Gary Aman) 4. 01:16 PM - Re: valve problem (BobsV35B@aol.com) ________________________________ Message 1 _____________________________________ Time: 07:34:58 AM PST US Subject: Re: JabiruEngine-List: valve problem From: FLYaDIVE Doug: Is this your post? "A couple years back we had a new Jab 3300 that had a real problem with valves sticking. Ultimately the valves bent and several had to be replaced. A casual notion would be that the valve guides were TOOOOO tight!!! However, inspection by Pete K and the folks in Tennesee revealed the presence of a gunky contaminate. It was that material that caused the valves to gunk up and stick. " It was posted by: Kayberg@aol.com via matronics.com And you can see the term "gunky" was used... Gunky is not a solid or a powder. That is what I am responding to. ================================ I did not see the first set of pictures. Isn't this engine out of country? Yellow - Is a classic case of SULFUR. So one must ask: Are these fuels controlled enough to keep the sulfur content equal to or lower of what we have here is the USA? Question: Are these Sulfur filled valves? We are only working from pictures so there is a lot the eye can see that the pictures may not show. Are the valves the ONLY place where the yellow is showing up? If so the next question would be: How hot is the engine/valves running? Hot valves could be causing detonation and it could be only in the vicinity of the valve. You can cross check this with the burn pattern on the top of the pistons. You want to see a very distinked swearl pattern. Can you add any additional pertinent information? Barry On Fri, Mar 16, 2012 at 5:26 PM, wrote: > ** > Barry, it wasn't coke. It wasn't carbon based. It was a yellowish > material that we believe was present in the mogas with ethanol. It showed > up in less than 3 hours of running, hardly enough to cause significant > carbon deposits. > > Doug > > In a message dated 3/16/2012 3:27:41 P.M. Eastern Daylight Time, > flyadive@gmail.com writes: > > Guys - please take note: > > In this age of instant communications it amazes me how information > isolated aviation people have become. I frequent different aviation online > groups and all have reported this SAME type of valve problem. It is nothing > new. What does amaze me it how technical engine manufactures can get. "Pete > K and the folks in Tennessee revealed the presence of a gunky contaminate." > That GUNK is known as coke, not the type that you drink but what happens > when you expose oil to high heat. This coke is a carbon base substance. > The coke attaches itself to the valve stem and guide; the coke is harder > than the steel of the valve or the valve guide and causes ware. This coke > hardens - And, the valve stem and valve guide ware allowing more oil leaks > into the space between the valve and guide. In engine design the valve is > harder than the guide so the guide wares more. As the coke builds up it > causes the valve to stick. History has shown when this happens the valve > sticks OPEN, in the DOWN position. Since the valve is DOWN it is met by > the UP coming piston. You can just imagine all the fun and sounds that > happen in a split second. What I do not know is: Dose the Jabiru have > an INTERFERENCE fit between the piston and valve? If not than all that may > happen is a loss of power; otherwise it's flying parts and vibration - If > you are lucky. This problem is more prevalent with engines that burn > AvGas but it does happen with MoGas also. > > How do you prevent it? The jury is still out on that verdict. But, there > is a test that can be performed that gives one a better than average idea > on when it is happening. Go to the Lycoming web site and down load Service > Bulliten SB388C. It explains the required equipment and how to perform > what is know as "The Valve Wobble Test". Remember: The equipment will have > to be modified and the specs (Go-No Go) limits will have to be developed to > address the Jabiru Engine. > > My thought on prevention is: COOL the valves and guides as much as you > can. Prevent the HEAT from burning the oil. If the oil does not burn coke > will not develop. > Side Note: Engine manufactures - If cooling does work you will have to > re-calculate the clearance between the valve stem and guide considering > the maleficent of expansion of the materials. Less heat means less > expansion unless you go with a NPO material. > > Barry > > > On Fri, Mar 16, 2012 at 1:42 PM, wrote: > >> ** >> For the folks following this thread, I would urge some level of caution >> and a high trust in USA Jabiru. >> >> A couple years back we had a new Jab 3300 that had a real problem with >> valves sticking. Ultimately the valves bent and several had to be >> replaced. A casual notion would be that the valve guides were TOOOOO >> tight!!! However, inspection by Pete K and the folks in Tennesee revealed >> the presence of a gunky contaminate. It was that material that caused the >> valves to gunk up and stick. The engine was torn down and checked, then >> reassembled. Other than a clean up, touch up of the seats and new valves, >> nothing was done. It is running fine today as far as I know. >> >> The heads in Tex's picture could have a bent exhaust valve (which can >> come from overheating), from dirt or problems with the seat, from >> overheating cooking the oil in that spot, or perhaps other causes, not >> excluding a problem with fuel contamination. We are not told of the number >> of hours on the engine, the compression numbers obtained on multiple >> occasions, CHT's and EGT's over time and other considerations. Frankly, >> if the compression is up, particularly a differential compression check, I >> would not do anything unless Pete, et al, said it was an indicator. >> >> While Tex wants to make his own valve guides, that would not be the >> solution I would pursue first. Having just discovered a cracked valve >> guide in a O-320 Lycoming, I tend to believe that some things just >> happen. Better to replace with the correct part and simply move on.....if >> the guide >> > * > > > * > > ________________________________ Message 2 _____________________________________ Time: 09:31:14 AM PST US Subject: JabiruEngine-List: 3300 First Run Oil Question From: "AZFlyer" According to the instructions provided by Jabiru on "First Start Procedure" the first item on their list is: 1. Fill oil cooler 2. Add 3.5 qt oil to the sump How am I suppose to fill the oil cooler? How much oil does it hold? Doesn't the oil go into oil cooler from the same filler as engine oil? After putting in 3.5 qts and a little more...I still don't get oil on the stick. Did remove spark plug from each cycl. and did turn over engine with starter per instructions...but still can't get reading on oil stick... what am I doing wrong? Thanks, M -------- Mike Miller @ millrml@aol.com 601 XL-B, 3300, Dynon Remember, "the second mouse gets the cheese"! Read this topic online here: http://forums.matronics.com/viewtopic.php?p=368771#368771 ________________________________ Message 3 _____________________________________ Time: 12:26:31 PM PST US Subject: Re: JabiruEngine-List: valve problem From: Gary Aman Bob, The issue of valve seat recession with early on unleaded fuel comes to mind , but you may never have had to deal with that in your frame of experience. That was addressed with additives as well as other additives for other issu es like alcohol separation,one of the reasons motor fuel smells so nice and does such a good job of removing sloshing compound from older aircraft fue l tanks.I could run the 87octane in the D35 with the E series engine, but a fter a while the fuel selector got too stiff to turn.A dose of 100LL freed it up quickly,so I figured it lubed it some as well,just had to run some 10 0 now and then.But you could be right and I don't mind.You will probably ge t your wish for unleaded 100 sooner than you might think.It's high on the E PA's list. Thanks,always enjoy your input,Gary Aman Mk3c Jabiru 2200a -----Original Message----- From: BobsV35B Sent: Fri, Mar 16, 2012 5:01 pm Subject: Re: JabiruEngine-List: valve problem Good Afternoon G.Aman, I do like the stability aspects of 100LL, but I think any thoughts as to th e cushioning and lubrication qualities of leaded fuel are pure unadulterate d Old Wives' Tales. The FAA ran a set of engines on an Aero Commander many years ago with one e ngine being fed only leaded fuel and the other fed only unleaded fuel. The one using unleaded fuel ran better, ran cleaner, and lasted easily through TBO. Lead is strictly a relatively low cost octane enhancer. If you do not need the octane, don't use leaded fuel! Too bad we do not have a source of unleaded aviation fuel. 80 octane would be more than enough for most small engines. Without lead, the 100 LL mix is good for 96 or 97 octane. Happy Skies, Old Bob AKA Bob Siegfried Downers Grove, Illinois In a message dated 3/16/2012 3:14:21 P.M. Central Daylight Time, zeprep251@ aol.com writes: Just as an aside, I believe the benefits of leaded fuel extend far beyond it's anti knock q ualities.The cushioning and lubricating features make it worth the differ ence in price as well as the fact that it stores without degradation.Any room for this thought in the valve guide discussion?Just my opinion.No offe nse meant. G.Aman Jabiru 2200A approx.680 trouble free hrs so far all on 100LL ________________________________ Message 4 _____________________________________ Time: 01:16:07 PM PST US From: BobsV35B@aol.com Subject: Re: JabiruEngine-List: valve problem Good Afternoon Gary, Just parroting what I have been taught by George Braly, Tim Roehl and many others who have seriously studied the issue. The folks who promote lead for cushioning and lubrication seem to be those same folks who claim that lean side operations are hard on our engines. As George is fond of saying: "It is not how hard we run our engines it is how we run our engines hard!" First heard such things back when I had a sail boat with an auxiliary engine (Atomic Four) of which the hand book said should only be fed "white" gas. About that same time there was an article in Sail Magazine purportedly written by the retired Ethyl engineer who had developed Tetra Ethyl Lead for octane enhancement. He mentioned that the lead had no real good properties at all other than as an Octane enhancer. It was, in fact, poisonous and bad stuff to handle. He wrote that when the PR people were trying to sell the public on using the Ethyl compound, they invented the idea that it may help lubrication and may cushion the valves. The engineers that worked for the Ethyl corporation stated that there was NO basis for making that claim, but the brass went with the PR folks and we are still suffering from that false premise. I do hope we get rid of lead. I also feel it is imperative that we get a 100 octane fuel by whatever means it can be done without using lead. I agree with those who say the amount of lead we use is not a health problem, but the lead is not good for our engines either! I hope George gets his no lead fuel (100UL he calls it) approved and I hope Swift fuel is also successful. Meanwhile, I want the lowest quantity of lead in my fuel that can do the job. Sure would make the plugs last longer! I figure the higher end solvents loosened up your fuel valve, but that is strictly a WAG! Happy Skies, Old Bob TN IO-550-B that needs that fancy fuel! W670 that doesn't care at all. Downers Grove, Illinois In a message dated 3/17/2012 2:26:56 P.M. Central Daylight Time, zeprep251@aol.com writes: Bob, The issue of valve seat recession with early on unleaded fuel comes to mind, but you may never have had to deal with that in your frame of experience.That was addressed with additives as well as other additives for other issues like alcohol separation,one of the reasons motor fuel smells so nice and does such a good job of removing sloshing compound from older aircraft fuel tanks.I could run the 87octane in the D35 with the E series engine, but after a while the fuel selector got too stiff to turn.A dose of 100LL freed it up quickly,so I figured it lubed it some as well,just had to run some 100 now and then.But you could be right and I don't mind.You will probably get your wish for unleaded 100 sooner than you might think.It's high on the EPA's list. Thanks,always enjoy your input,Gary Aman Mk3c Jabiru 2200a ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message jabiruengine-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/JabiruEngine-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/jabiruengine-list Browse Digests http://www.matronics.com/digest/jabiruengine-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.