BrianL29

Thanks Paul. Good talking to you on several platforms! I did pull the mixture back to 13 GPH quick. I was pretty sure I would be lean of peak at that point based on others data. CHT's are dropping dramatically, so I'm still not sure how I'm not lean of peak at that setting. I'll perform the LOP Mag test again.

I was experimenting with lean of peak settings in my Bravo that others have used. 29-30 MP 2200-2300RPM 13GPH. My engine runs fine, but my EGT's & TIT never drop even when CHT's are dropping and my TIT is over 100F higher than my EGT's? (over 1700F). So I enrichen to prevent turbo damage. Is it even possible for TIT gas to be that much higher than EGT? Doesn't make sense to me. Or why my EGT's aren't dropping when CHT's are? Maybe my TIT is just reading too high?

Thanks for all the ammunition. During the IRAN they replaced the lifters and the camshaft. Valves and springs were reused. I will make sure lifter clearance is checked and we are replacing all the springs. Compression check would be interesting as well. I upgraded my savvy membership for additional support. Lousy problem but I’m learning a ton about engines! Sent from my iPhone using Tapatalk

Engine shop says- 1. overrevving engine when cold-They quoted Lycoming to not apply power before oil is up to 160F. 2. springs are just coiled steel rod and have cycle limits...or might have been a bad batch. You cant NDT them, so no way to know if they are good during an IRAN. You'd think they'd at least pretend to review the IRAN documentation and look for possible issues. Any opinions on the picture of cylinder with oil at the bottom? Normal or excessive?

Yes, 2 different cylinders have had broken intake valve springs. First one was about 20 hrs after IRAN and the 2nd was about 35 hours.

I found something. Looks like more broken intake valve springs on #5. Not feeling good about my engine. Borescope pictures of valves and guides looked ok. Sending to savvy to doublecheck. There was some oil in the bottom of both cylinders. Bottom plugs looked a bit wet. Think this is excessive? Its been sitting 4 days since the engine ran.

Thanks for the input. I agree, I need to have an A&P look at it. My primary mechanic just retired and my back-up moved away, so I'd like to do as much of the diagnostics as I can before I let someone tear into it. If anyone has any recommendations in northeast Ohio, let me know.

Good idea on inspecting the valve springs. I need to narrow the problem down somehow. I agree on the shop excuse being BS. I picked the wrong shop and regret doing an Iran vs overhaul. Live and learn. Any opinions if I should continue to fly before solving the problem? I can’t decide if this is a nuisance start up problem or a time bomb. Sent from my iPhone using Tapatalk

Engine shakes pretty good if I increase power that much. Leaning doesn’t change much. I keep it as lean as possible while I’m trying to revive it.

I haven’t had both come on line by just leaving it running. I’ve had to stop and restart the engine. I’m guessing the longest I’ve let it run is maybe 10 minutes. My savvy analysis indicated a potential valve failure on #3. I borescoped last month and everything looked good on that cylinder. I’ll have to check others. Is it possible I’m getting too much fuel on initial start and soaking those plugs?

When springs broke I landed fine pulled off the runway and the engine started shaking violently. I saw no EGT on #3. Obviously didn’t come back to life. We found both intake valve springs broken. Shop said that the new camshaft installed probably over compressed original springs and broke them. My current problem seems to correct itself with time. I haven’t pulled valve covers but doesn’t feel like the issue. Sent from my iPhone using Tapatalk

Normally 4 comes on line first and then 5. But I may have to restart a couple more times to get 5 going. Its runs smooth as soon as they are all running. Cylinder 3 had the broken spring.

Hey all, Strange problems started late November on my Bravo. Latest in a series of them on my IRAN engine with about 40 hours on since then. When i start the engine, cylinders 4 and 5 do not fire up. I let it idle for a while and typically no luck. I have to stop and start the engine 5-10 time and eventually they all fire. During my re-starts I am doing a flooded engine start and trying to keep mixture as lean as possible and throttle close to idle and that seems to help. The first time this happened I remember accidentally trying to start with the mixture at idle. I stopped and tried again and had the throttle a bit too far forward and it roared to life a little harder than I would have liked. The engine used to start on the first blade turn. When it does catch quickly, then it does seem to start ok. Lately it seems to crank for 4-5 seconds before it start and that is when those 2 cylinders don't light. My engine has been buggy. I had broken intake valve springs at hour 20. The crankcase seal pushed out around hour 27. When it does start it runs smooth and EGT and CHT's look good. Any thoughts? Do you think the plugs are getting wet? I installed fine wire plugs mid October. I am tempted to put the old plugs back in to see what happens.

I think I will overhaul the mag I have on the shelf with Van Nuys or AAO and try replacing the Kelly Aero mag. Is this Van Nuys? http://aeroacc-vny.com/

That's interesting on Kelly Aero. I have another slick sitting on a shelf when I installed the Surefly. Maybe I'll send it to Van Nuys for an overhaul. The slick start mag booster is intriguing for a Bravo. I didn't know those existed. Thanks. And I did install fine wires about 15 hours ago and they didn't change any of my numbers, except for the ones in my bank account. If anything its a little trickier to hot start.