Rick Junkin

I am able to run at 70% 35dF LOP as calculated at 13.2gph with all temps well within limits. I've posted this before; unfortunately it's a low altitude example but it shows all the important parameters. CHTs increase modestly at altitude but remain well below 380dF. I can run at 14.2gph / 75% but the TIT goes to about 1610 and I'd rather keep it below that. I accept the 8-10 knot hit on airspeed and cruise at about 175KTAS in the mid - upper teens. Again, it isn't fuel economy I'm looking for, it's cleaner and cooler engine operation. One of these days I'll remember to grab a screen shot at altitude. EDIT: Added screen shot of LOP % power spreadsheet.

I know I’m an outlier with a Bravo that runs well LOP. I do run Tempest fine wires and GAMIjectors with a 0.3gph spread, and work at staying on top of the ignition system condition and timing. Running at 2200 RPM also helps with LOP ops and I’m happy with the speeds I get. As was said, to each his own. For me it isn’t the fuel savings as much as it is the cleaner running and the lower CHTs. The plugs are always clean and the cylinders and valves always look great through the borescope at oil changes. Time will tell on the engine longevity but all indications are good and I’m optimistic.

Ok. So what? EDIT: I see Don went back and added to his post after I quoted his original post. He can’t get his engine running smoothly LOP. I can.

I'll leave @Jetpilot86 to speak for himself, but yes, we both run our Bravos LOP. I run 30"/2200RPM at 13.2gph, which is 70%. My TIT stays below 1600, typically ~1585, for a nominal 175KTAS in the mid teens. 14.2gph yields 75% and that's about where Bret runs in cruise. I'm sure he'll be by shortly to provide his parameters.

It's the base of the #2 riser. I didn't see it on visual inspection, and only caught it when overspray from the slip joint I was looking at started bubbling.

For clarification, did #1 EGT drop TO 180dF, or drop BY 180dF? If it dropped TO 180dF then you lost all combustion in #1 and that most likely points to faulty ignition. I would suspect you felt some roughness in the engine if this is the case.

Thanks for catching that, my bad. Yes. <4K ohms. I corrected my original post.

Your #1 CHT is out of phase with the rest of the cylinders so I don't think you have an EGT or CHT probe issue. There's something happening at full power on #1 that resolves at cruise power. 1748dF EGT is troubling, and implies either a too lean mixture or a bad plug. Since the problem resolves at cruise power and the fuel side has been checked I'd look at both #1 plugs. An extended runup check at a lean mixture might show you if one of the plugs is dropping out. Otherwise pulling them both and checking that resistance is <4K ohms as has been suggested might show which plug is bad, if either is. What plugs are you running? Cheers, Rick

I turn the GPU on and verify stable power first, and then connect it to the airplane. That’s what the White Lightning GPU owner’s manual says to do, and it’s how we did it on military jets.

I looked into this on the website and the form for the conversion states they’ll only convert units less than 3 years old. Unfortunately I’m well outside that window.

...and then I discovered the crack in my exhaust All for naught, the whole shebang is going out for overhaul, including the heat shroud. Actually I guess it wasn't for naught - I may not have discovered the exhaust crack had I not been working on the shroud in the first place, and decided to pressurize the exhaust while I had it off. How fortuitous.

You forgot to mention it requires brute force and some amount of cursing. But I guess that goes for just about every job in the Bravo engine compartment. i got it out and discovered that a poor attempt had been made to effect a previous repair in the same area. I need to stop drill several cracks, make a doubler and rivet it in place, and rivet the outlet tube onto the repaired area. Lots of supervised work on this one. Thanks for the help!

DOH!!! Exactly. I eliminated the cigar lighter receptacle and added dual USB ports to both sides of the panel. And then I got an Inogen G5. Fortunately I have a cigar lighter receptacle on the back wall of the baggage compartment so I can plug in there.

Thanks! I didn't want to cut into it if that wasn't the approved solution. The intake and induction filter have been removed for access.

@philiplane Can you give me some pointers on the best way to remove the heat shroud from the exhaust cross-over tube? Mine has what looks like heatproof fabric on it that covers the split on the top of the shroud for the exhaust cross-over tube tether cable and we can't see how to get it off around the cable without destroying the fabric. Or even how to cut the fabric if that's what it takes. Mine's damaged (the angled output tube broke free) and we can't repair it in place. I know we're missing something. It can't really be this hard, its supposed to be removed for inspection of the cross-over every annual. Thanks for your help and expertise! Cheers, Rick