Failure to Rotate - Burned Valves
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- čas přidán 15. 06. 2022
- Savvy Aviation's Mike Busch discusses the function of exhaust valve rotator caps and their importance to keep unwanted deposits from sticking to the valve seat. Mike will review the causes of burned exhaust valves, and discuss ways to prevent this from happening. Savvy Aviation offers Professional Maintenance Services to owners of General Aviation aircraft, such as: SavvyMx (Professional Maintenance Management), SavvyQA (Expert Consulting), SavvyPrebuy, SavvyAnalysis (Engine Data Analysis) and Breakdown Assistance. Savvy also publishes a monthly newsletter with lots of interesting information for the general aviation enthusiast; subscribe to it at www.savvyaviation.com or text the word "Savvy" to 33777. This webinar was hosted by the Experimental Aircraft Association (EAA).
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HELPS A LOT .. . VERY WELL EXPLAINED . . . THANK YOU SIR
Mike, extremely valuable information for a new airplane owner and prospective AMT. Thank you for these videos!
Thanks for all you do Mike. Very informative as always.
I took his engine course years ago, he discussed with engine monitor setting to normalize and then doing inflight mag check, you will see temps change as the valve rotates if there is a leak and it will be cyclical, like every minute or so. Interesting he did not mention that this talk.
Good job Mr Mike. Tanks for the video.
You are very welcome
DOHC, more valve, seat, stem and guide to absorb heat. Also on a bucket lifter, the cam lobe often runs slightly off centre so it rotates the valve every time it contacts plus the bucket prevents the valve from wobbling side to side, reducing valve guide wear.
@1:40 LOL…from the wording, I was imagining Mike as a middle-school chaperone hyperventilating about said middle schoolers “wiggling and rubbing” against each other…😳😉🤣🤣🤣
Sorry, I couldn’t hellp myself…it gave me a pretty healthy guffaw even if in poor taste considering so many peoples’ “delicate sensibilities” and absolute REQUIREMENT to “signal squeaky-clean virtue”. Cheers, people need to loosen their brain tourniquet a bit I think all around and smile and laugh more…🖖😎👍 Peace and love to all, may we all get through the next few years without losing our collective minds!
I have a Continental O-300 that keeps burning the exhaust valve on the #2 cylinder. Is there a rotator on these valves?
Mike mentions in the Q&A that the O-300 doesn’t have rotators. Perhaps the valve seat is not concentric with the valve guide.
@@darrylday30 I have had the same issue with two different cylinders though. I’m wondering if there is a angle on the rocker that would make the valve rotate. I have had at least four different A&P’s work on it and one engine shop. All other cylinders are running great. ????
@@shanelarsen1436 I’m not an expert like Mike but I’ll do my best. I’m assuming that when you say you’ve had the same problem with two different cylinders that both of these cylinders were installed and operated in the same #2 cylinder position on the engine. If that is the case, I would recommend checking for an intake manifold leak adjacent to the #2 cylinder (look for a 100LL blue stain indicating a crack or leaking seal). A manifold leak adjacent to the #2 cylinder would cause a leaner mixture and higher temps on any cylinder installed in that position. CHT/EGT for each individual cylinder would be helpful for trouble shooting this but I’ve never actually seen that on an O-300. You want to stay on top of this. Scope it often. Solve the problem. Loosing a valve on takeoff is very dangerous. I’ve been there with the stall warning blaring, controls sloppy and desperately looking for a place to crash.
@@darrylday30 I have put a new Superior cylinder on it and it lasted about 200 hours. The other three times I have just had the cylinder overhauled and they last between 50-100 hours. I have checked the pushrod for proper length and oil flow and the rocker for proper oil flow. I also verified the oil flow by turning the motor over with the mags off and watched the oil flow out of the rocker. I found a spot in the intake runner where it bolts to the head that had a dark brown spot on it that might have been an intake leak so I took care of that. I have checked the travel of the rocker compared to the number 4 cylinder and they were the same so I don’t think the cam is going flat either. It just isn’t that complicated of an engine but it’s hard to find guys with in-depth knowledge of this issue.
@@shanelarsen1436 Cam and lifters would be worth a look as they’re easy to get at. However, I’d recommend contacting the manufacturer. There is zero chance that you’re the first person to have this problem and there’s an almost 100% chance that they’ve solved your problem previously with someone else. Be concise and precise. Don’t guess. Give them the details with pictures and measurements if possible. Be prepared to gather more data. Finally get back to me if you can and let me know how things worked out.