Cylinder head woe!! - Zenith Aircraft Builders and Flyers2024-03-28T21:03:05Zhttps://zenith.aero/forum/topics/cylinder-head-woe?commentId=2606393%3AComment%3A847873&feed=yes&xn_auth=noUpdate to issue...
Ray Lawere…tag:zenith.aero,2021-10-06:2606393:Comment:8495492021-10-06T20:23:45.133ZDavid J. Beaulieuhttps://zenith.aero/profile/DavidJBeaulieu
<p>Update to issue...</p>
<p>Ray Lawerence of UL supplied me with a used cylinder head assembly after having it looked over by the machine shop he routinely uses. <strong><em>Did I mention he did it for free?</em></strong></p>
<p>I did send him my assembly with the crack and I believe it is going back to the factory for assessment. I suspect that a root cause of the problem will likely not be found but there are more than a few mysteries in the history of the aviation maintenance…</p>
<p>Update to issue...</p>
<p>Ray Lawerence of UL supplied me with a used cylinder head assembly after having it looked over by the machine shop he routinely uses. <strong><em>Did I mention he did it for free?</em></strong></p>
<p>I did send him my assembly with the crack and I believe it is going back to the factory for assessment. I suspect that a root cause of the problem will likely not be found but there are more than a few mysteries in the history of the aviation maintenance world.</p>
<p>Support from Ray has been great (as usual) as he fielded my phone calls and endured my questions. Really couldn't ask for any better support overall. (O.K. maybe Wicks or UL could have had one on the shelf ready to go? LOL)</p>
<p>For now, after a 3 1/2 week down time, "Sky Turtle" is back flying and hopefully will be good to go for a long time.</p>
<p>Dave</p> I'm finding the decision for…tag:zenith.aero,2021-09-20:2606393:Comment:8478732021-09-20T14:37:30.544ZBob Widmerhttps://zenith.aero/profile/BobWidmer
<p><span>I'm finding the decision for an engine for my 750SD a little daunting as I'm flying in the mountains and must feel confident that the engine is reliable and strong. That said, there are no assurances on any engine and reading about your problems Dave gives me pause on ordering the UL520T.</span><br></br><br></br><span>As for the other alternatives, here is a comment on a Titan on the VAF forum site indicating there are problems with all engines - the comment dated 9/10/21 is particularly…</span></p>
<p><span>I'm finding the decision for an engine for my 750SD a little daunting as I'm flying in the mountains and must feel confident that the engine is reliable and strong. That said, there are no assurances on any engine and reading about your problems Dave gives me pause on ordering the UL520T.</span><br/><br/><span>As for the other alternatives, here is a comment on a Titan on the VAF forum site indicating there are problems with all engines - the comment dated 9/10/21 is particularly interesting:</span></p>
<p></p>
<p><a href="https://vansairforce.net/community/showthread.php?t=199058" target="_blank">https://vansairforce.net/community/showthread.php?t=199058</a></p> Dang David not another engine…tag:zenith.aero,2021-09-19:2606393:Comment:8479472021-09-19T20:29:11.937ZDoug Malloyhttps://zenith.aero/profile/DougMalloy
<p>Dang David not another engine problem. Your engine is proving to be a real Citroen. Hopefully the UL folks provide assistance. We, with ULs, are keenly interested in how the company handles your experience with their product.</p>
<p>Dang David not another engine problem. Your engine is proving to be a real Citroen. Hopefully the UL folks provide assistance. We, with ULs, are keenly interested in how the company handles your experience with their product.</p> Good grief David.
You have h…tag:zenith.aero,2021-09-19:2606393:Comment:8477582021-09-19T03:11:41.163ZTimothy Aanerudhttps://zenith.aero/profile/TimothyAanerud
<p>Good grief David. </p>
<p>You have have had more than your fair share of troubles with your engine.</p>
<p>Has ULPower(the factory), Robert and/or Ray been helpful with getting your engine repaired and with trying to resolve/investigate/determine the cause of your multiple engine troubles?</p>
<p>Good grief David. </p>
<p>You have have had more than your fair share of troubles with your engine.</p>
<p>Has ULPower(the factory), Robert and/or Ray been helpful with getting your engine repaired and with trying to resolve/investigate/determine the cause of your multiple engine troubles?</p> Hey Bob, I guess anything is…tag:zenith.aero,2021-09-16:2606393:Comment:8474642021-09-16T12:28:08.489ZDavid J. Beaulieuhttps://zenith.aero/profile/DavidJBeaulieu
<p>Hey Bob, I guess anything is possible. Dynon data did record a CHT limit exceedance about a month ago on a flight that I remember well. It was on departure after a waterway takeoff and it spiked quickly. I had to keep flying and climbing due to terrain. After leveling and heading back to the hangar the CHT came down a bit with power reduction but remained in the upper "yellow" range near max allowable for the flight. At that time I was thinking it was simply a bad probe. The engine…</p>
<p>Hey Bob, I guess anything is possible. Dynon data did record a CHT limit exceedance about a month ago on a flight that I remember well. It was on departure after a waterway takeoff and it spiked quickly. I had to keep flying and climbing due to terrain. After leveling and heading back to the hangar the CHT came down a bit with power reduction but remained in the upper "yellow" range near max allowable for the flight. At that time I was thinking it was simply a bad probe. The engine was running well with no noticeable loss of power. Maybe that is when the initial crack started? Maybe due to partially clogged injector which cleared but precipated the event and the crack? During troubleshooting I eventually even considered the possibility of corrupted ECU programming. Over the next 3 or 4 flights and attempted troubleshooting the CHT just kept getting hotter more quickly until enough was enough! I suspect the crack was just propogating a bit everytime I took it out for testing resulting in hotter CHT and loss of some power as well. </p>
<p>I should be getting a new cylinder head with a couple of weeks and I'm looking forward to getting back in the air! Hope your project is going well...</p>
<p></p>
<p>Cheers!</p>
<p>Dave</p> David. Years ago I had a Turb…tag:zenith.aero,2021-09-15:2606393:Comment:8472392021-09-15T22:54:15.585ZBob Widmerhttps://zenith.aero/profile/BobWidmer
<p>David. Years ago I had a Turbo Arrow and while climbing out of the airport I had a cylinder temperature rise to the point it blew a hole in the cylinder. I was about 20 miles from the airport, pulled the throttle back, full rich, kept the cowl flaps open and and initiated a dive. All to no avail. Before long there was smoke in the cabin from oil into the exhaust. <br></br><br></br></p>
<p>Upon tear down of the engine the opinion was that an injector became partially plugged leaning that cylinder to…</p>
<p>David. Years ago I had a Turbo Arrow and while climbing out of the airport I had a cylinder temperature rise to the point it blew a hole in the cylinder. I was about 20 miles from the airport, pulled the throttle back, full rich, kept the cowl flaps open and and initiated a dive. All to no avail. Before long there was smoke in the cabin from oil into the exhaust. <br/><br/></p>
<p>Upon tear down of the engine the opinion was that an injector became partially plugged leaning that cylinder to the point the temperature continued to rise. Who knows how that would happen. <br/><br/></p>
<p>Is it possible the same thing happened in your case?</p>
<p></p> Backside view of cylinder hea…tag:zenith.aero,2021-09-14:2606393:Comment:8473562021-09-14T00:04:09.841ZDavid J. Beaulieuhttps://zenith.aero/profile/DavidJBeaulieu
<p>Backside view of cylinder head crack after removal from cylinder. Cylinder walls look good and so does the piston.</p>
<p><a href="https://storage.ning.com/topology/rest/1.0/file/get/9563768101?profile=original" target="_blank" rel="noopener"><img src="https://storage.ning.com/topology/rest/1.0/file/get/9563768101?profile=RESIZE_710x" class="align-full"/></a></p>
<p>Backside view of cylinder head crack after removal from cylinder. Cylinder walls look good and so does the piston.</p>
<p><a href="https://storage.ning.com/topology/rest/1.0/file/get/9563768101?profile=original" target="_blank" rel="noopener"><img src="https://storage.ning.com/topology/rest/1.0/file/get/9563768101?profile=RESIZE_710x" class="align-full"/></a></p> Sometimes I think I'm getting…tag:zenith.aero,2021-09-12:2606393:Comment:8470132021-09-12T22:53:07.086ZDavid J. Beaulieuhttps://zenith.aero/profile/DavidJBeaulieu
<p>Sometimes I think I'm getting closer to seriously considering crossing that bridge Bob! The cracked lug on the early model cylinder with the resultant oil leak I can accept as being part of the "early adopter" crowd. The oil filter backing off during cruise - well I will attribute that to poor harmonics on the Catto prop/engine combo and not being aware/proactive enough to safety the filter per standard practice on GA aircraft - though the UL mx manual does not call out for having it…</p>
<p>Sometimes I think I'm getting closer to seriously considering crossing that bridge Bob! The cracked lug on the early model cylinder with the resultant oil leak I can accept as being part of the "early adopter" crowd. The oil filter backing off during cruise - well I will attribute that to poor harmonics on the Catto prop/engine combo and not being aware/proactive enough to safety the filter per standard practice on GA aircraft - though the UL mx manual does not call out for having it safety wired! I have a harder time on having a cylinder head crack after less than 300 hrs. Though, even the major manufacturers have had issues with a variety of cylinders, etc. with numerous SBs and ADs. I will say that I am glad to have CHT and EGT monitoring on all cylinders! Paying attention to things helps with avoiding some lousy outcomes.</p> "Wow" that was a good catch b…tag:zenith.aero,2021-09-12:2606393:Comment:8471612021-09-12T22:11:24.476ZBob McDonaldhttps://zenith.aero/profile/BobMcDonald
<p>"Wow" that was a good catch by pilot / builder. I'm thinking its time to consider a repower with a more traditional "proven" aircraft engine. If you lose confidence in the engine the choice is simple. </p>
<p>"Wow" that was a good catch by pilot / builder. I'm thinking its time to consider a repower with a more traditional "proven" aircraft engine. If you lose confidence in the engine the choice is simple. </p>