My IO550N-19B Top End Overhaul

Questions, best practices, and general info regarding getting your hands dirty

Moderators: George Wehrung, Admin

Post Reply
George Wehrung
Posts: 185
Joined: Tue Nov 22, 2022 3:56 pm
Location: KMRH

Yeah I know Mike Busch says don’t do it….

But I am left with no choice but to pull the cylinders.

Issue: oil is blowing by 3 of my cylinders likely due to stuck oil control rings or worn cylinder walls. You know you have a problem when oil drips off the bottom of your rudder in the hangar. No I don’t over fill my sump as I keep it less than 6 qts. No it’s not the nose seal. Yes the oil sump is over pressurizing. I have a nice oil streak from my vent tube down the belly of the plane.

The Plan: pull all six cylinders and also inspect cam shaft. If I see galling or pitting the engine gets an overhaul. If ok the cylinders are going to Sal’s Cylinders just North of Dallas.

Additional items to do: have fuel pump rebuilt $475.00. Have prop governor overhauled $675.00. Replace crank case nose seal because it’s easy to get to. Send off my WMI nose strut to get overhauled.

I will also do my annual condition inspection and in that I will replace my brake pads and also replace my Garmin pitch and roll servos per their SB.

Progress: just getting the baffling off and now on a trip for another week and a half.


Sent from my iPhone using Tapatalk
J.C. Peterson
Posts: 21
Joined: Sun Dec 18, 2022 3:33 am

George,

How much time do you have on the engine?
George Wehrung
Posts: 185
Joined: Tue Nov 22, 2022 3:56 pm
Location: KMRH

I have 1100 hrs or so


Sent from my iPhone using Tapatalk
Robert Pastusek
Posts: 10
Joined: Tue Nov 22, 2022 6:48 pm

George
If the oil pressure is good, a top overhaul can work well, and is much less expensive. IMHO, the critical step is re-tightening the overhauled cylinders. NO paint on the bolts/cylinder clamps at the mating surfaces; follow the Continental manual exactly on tightening sequence/procedure. E.G. torque the through bolts from both sides, etc.
OH of the fuel pump is a good idea; consider OH of the spider as well.
Bob
George Wehrung
Posts: 185
Joined: Tue Nov 22, 2022 3:56 pm
Location: KMRH

Thanks Bob, I bet the fuel pump guy can do the spider as well?


Sent from my iPhone using Tapatalk
lourubin
Posts: 4
Joined: Sun Apr 16, 2023 3:32 pm

Im with you George . Many Tops can be prevented, but not all of them. Im in the same boat with only 70 hrs. We found a corroded cam and crank that tested good on oil analysis and filter inspection.The only way to know for sure is to remove the jugs and alternator. My rings lost temper and even though my compressions were in the high 70s the engine used oil. Thats another testament that compressions are a guide, not a final ruling on engine health. Unfortunately my expense will go far beyond a top, however id rather address this now than on a trip with the engine making metal.
George Wehrung
Posts: 185
Joined: Tue Nov 22, 2022 3:56 pm
Location: KMRH

I agree Lou. I am also sending out my fuel pump and spider as well as the prop governor


Sent from my iPhone using Tapatalk
Post Reply