Power settings

[Rick Junkin]

@Patrick Horan Have you had your mag timing checked recently? Should be 20 degrees BTC. 

I’m surprised you were LOP at 30/2200 at 15gph. What was your peak TIT and what was the fuel flow at peak? I see peak TIT at about 14.6gph at 30/2200.

A lot of things look out of whack so I’d like to confirm your fuel flow is accurate, your mag timing is correct, and your TIT is accurate. I mentioned before that your TIT indications look about 100 low relative to your EGTs. How many hours ago was the TIT probe changed last?

Cheers,
Junkman

[Fritz1]

Changing the TIT probe after 500h is a good idea, they just get fried and read low, also do a GAMI lean test and find the gph spread between your EGT peaks, use power setting 26"/2400 or below for the lean test 

[Patrick Horan]

6 hours ago, Rick Junkin said:

@Patrick Horan Have you had your mag timing checked recently? Should be 20 degrees BTC. 

I’m surprised you were LOP at 30/2200 at 15gph. What was your peak TIT and what was the fuel flow at peak? I see peak TIT at about 14.6gph at 30/2200.

A lot of things look out of whack so I’d like to confirm your fuel flow is accurate, your mag timing is correct, and your TIT is accurate. I mentioned before that your TIT indications look about 100 low relative to your EGTs. How many hours ago was the TIT probe changed last?

Cheers,
Junkman

I wish I can answer those questions. I kinda forgot.

My mechanic hasn't checked the mag time. He is cleaning the fuel injectors. He tested the probes and they are all indicating normal. But here is the sad news......

Cylinder #5 is completely dead. It scored a 4 on the compression test. My mechanic borescoped it and oil is kinda puddled in that cylinder. Kinda sucks I just got this plane from Maxwell. 

On other news he checked/borescoped the other cylinders. My two problem cylinders were actually the best!! #1 & #3 were 76 and 78!! He borescoped those and and everything looks clean. #2 and 4# the valves seem to have a slight bend.

[GRM321]

This is the typical summer temps for my Bravo 20 degF LOP in cruise. 500-700 fpm in the climb to 17.5k’ with cylinders below 385 degF at 2400 RPM/33 inHg/26.5 gph. 

[Fritz1]

Ah, that sucks, sorry to hear, since at least one cylinder is coming off excellent opportunity the check all lifters and cam lobes, ask your mechanic about torque plates for the cylinders that are off so you keep tension on the through bolts

[Rick Junkin]

17 hours ago, Patrick Horan said:

Cylinder #5 is completely dead. It scored a 4 on the compression test. My mechanic borescoped it and oil is kinda puddled in that cylinder.

Don't give up on that cylinder quite yet unless there is a smoking gun that says it is bad, or there is some other indication of a problem other than the compression test. Oil puddling, depending on how much is there,  can be explained in some cases by aligned ring gaps.

Continental has a service bulletin SB03-3 about what to do when a cylinder "fails" a compression test and it can be used as a reference for your Lycoming too, if you want to use it in light of the fact that Lycoming is silent on the matter. Basically it says to fly the engine for an hour and check it again.

As for #2 and #4, can you post pictures? I'd like to see what a bent valve looks like through a borescope so I know what to look for.

Cheers,
Junkman

DIFFERENTIAL PRESSURE TEST AND BORESCOPE INSPECTION PROCEDURES FOR CYLINDERS..pdf

EDIT: How much oil are you using? How many hours before you need to add a quart?

[Fly Boomer]

39 minutes ago, Rick Junkin said:

I'd like to see what a bent valve looks like

I didn't respond before, but I wonder why the mechanic is cleaning injectors if the engine really has bent valves.

[Patrick Horan]

2 hours ago, Fly Boomer said:

I didn't respond before, but I wonder why the mechanic is cleaning injectors if the engine really has bent valves.

I meant to say he cleaned the injectors before everything. I just came back from a long trip and wanted him to clean the injectors. He did that then did a compression check and borescope and found cylinder #5 to be bad. 

[Rick Junkin]

12 hours ago, Patrick Horan said:

I meant to say he cleaned the injectors before everything. I just came back from a long trip and wanted him to clean the injectors. He did that then did a compression check and borescope and found cylinder #5 to be bad. 

@Patrick Horan On your trip did you have any indications that #5 wasn't behaving properly? If it were truly not generating any compression I would expect you would see some anomaly in the EGT/CHT, although with a six cylinder engine you may or may not feel it in the engine operation unless you were specifically looking for it.

[Patrick Horan]

3 hours ago, Rick Junkin said:

@Patrick Horan On your trip did you have any indications that #5 wasn't behaving properly? If it were truly not generating any compression I would expect you would see some anomaly in the EGT/CHT, although with a six cylinder engine you may or may not feel it in the engine operation unless you were specifically looking for it.

The temperature seemed to be normal. I would say that plane did feel a little sluggish on Takeoff, but that could be related to a multiple different factors. 

[FoxMike]

The rings in your cylinders constantly move around.  Once in a great while, the ring end gaps line up and your compression goes way down.  The only way to tell if that is the problem is to fly the airplane for 4 or5 hours.  You might try this before you pull the cylinder.