Rough engine and low EGT on #2 just after t/o. Any ideas?

[ao.frog]

I just wanted you all to know that I've heard from both Larry Vetterman and Clint by now. I even got their replies on a SATURDAY! Impressive!
Both of them where very helpful and gave me very valuable info.

Clint sent me detalied instructions about how to weld the broken pipe.
I'm going to contact a certified aircraft welding shop in my local area and see if they can weld the pipe according to Clint's instructions.
If not, I'll send the pipe to Clint for the repair.

He promised a quick repair and he even offered to pay the return shipping. VERY NICE customer care!

I'll let you know how it turns out and ofcourse how the testflight goes, once the repair is done.

So far, I'm very happy with the service I've gotten from both Clint and Larry. (the latter is retired, but he still took the time to answer me. Good guy!)

[Clint B]

Originally Posted by Doug

Clint,
I thought the hose clamp was for the EGT probe and we all have those. Isn't the slip joint further down the pipe?

I like the idea of anti-seize on the ball joints. Good idea?

The hose clamps on the EGT probes are normal. Unless your EGT probes are more than 4 inches below the flange, they will be above the slip joints on all of the systems we manufacture. Putting a hose clamp over a slip joint will compress them over time and cause the slip joint to seize up.
Anti seize works well but won't creep into a slip joint or ball joint the way mouse milk will. Mouse milk was originally designed as a turbo charger waste gate lubricant and will help dissolve carbon residue, helping to keep ball and slip joints free.

[ao.frog]

Here's an update of the repair-process:

The Norwegian Airplane repair shop in our local area didn't have the correct welding rods or the correct material.
Therefore, I shipped the pipe on Friday the 5th of Sept to Clint in the US.

He got the pipe on Saturday the 20th and yesterday (Mon 22nd), the welded pipe was out of the door again and on it's way back to Norway.
That sure was a speedy repair! And even during a weekend! Impressive!

Not only did Clint do the repair for free, but he also covered the return shipping.

This is VERY nicely done of him and I'm very impressed with his willingness to stand behind their product!
It's good to know that there's help out there when you need it!

So right now, I'm eagerly waiting for the pipe to get here, probably in a couple of weeks.
I'll post another update when it's here and the -7 is back in the air.

So far: WELL DONE Cint!

[ao.frog]

Here's an update and hopefully the cause of the problem:

I received the repaired exhaust pipe a few weeks ago, and the repair-work done by Clint was very nicely done:










The reason WHY the little tab (LV-706) failed in the first place, has worried me quite alot, and finally I think I found the answer, and the fault was mine:
I had installed the two support pipes with too little spacing, so my guess is that the rubber-hose didn't absorb the vibrations the way it was supposed to.



I contaced Clint again, and he said that the ideal spacing beetween the pipe-ends would be 1/2 inch.
As you can see on the pic above, my spacing was alot less.






After cutting off alittle on one end on both starboard and port sides, the result was this:



After this pic was taken, I adjusted the angle of the starboard support-rod so it ran in a straight line from the 706 tab to the exhaust pipe.
(as you can see on the pic, it's alittle curve on the support-rod)

I've flown about 7 hrs since the repair, and so far everything is back to normal.

[Speeddog7]

Originally Posted by Lars

If everything else has been ruled out and the engine happens to be an older Superior 360 with roller cam, then it could be a stuck lifter (note that in this case it'll be an automotive roller lifter, not a Lycoming type with removable plunger). This happened to me, and it was not easy to diagnose. Much time spent staring at engine monitor datalogs.

Lars, I believe I'm experiencing an issue with a roller lifer in an early Superior IO-360 engine (500 hrs.). What did you end up doing to resolve the issue considering the Superior SV72800 Roller Lifter is no longer available? I really do not want to split my engine case!!

[Tankerpilot75]

Originally Posted by brad walton

I will be interested in what you find because I have had the same thing happen to my Superior IO-360 on several occasions. #2 cylinder drops to 650 degrees and it runs rough. Mine has occurred during LOP operation and once when I cut the throttle abruptly while in cruise flight. I switched the plugs with the #4 cylinder and still had it happen. No sign of intake leak. Slick mags timing is good and no obvious problem with the wiring. Mine is intermittent and usually only for 15 seconds or so. I have performed the ignition system stress test (LOP in cruise and switch off one mag, then the other) and nothing obvious on the graph to indicate a problem. Maybe the exhaust valve is hanging up?

Check your p-lead on you mags and confirm everything is tight. I experienced similar intermittent problems and discovered my p-lead ground that screws into the left mag was loose. Once tightened problem disappeared.