Engine scenario questions please. "Zero Time?"

[Mcstealth]

We have the Darters engine in pieces. We have everything ready to reassemble. The engine has 400 hrs on it. 150hp Lycoming. Don't know which model(sorry)

This all started with a per-snickity A/P who stated the crank had corrosion, at the 100hr inspection. We were skeptical, and were proven correct getting the green light by Engine Specialties. The cam did not pass inspection though. Neither did the con rods. 

So here is the question. Would you take the time and monetary investment and send in the cases? Do what it takes to zero time the engine? What do you need to actually zero it out?

Also, we have two new cylinders which we have decided to install. 

Thanks

David

[PeteMc]

91.421, only the manufacturer or an agency approved by the manufacturer can grant zero time to an engine.  

When I bought my plane it was be listed as a Rebuilt Engine, but they did not call it a "Zero Time" engine.  And in reality going through the logs it was only a tear-down due to a minor prop strike while taxiing.  Engine shop that did the tear-down was very reputable, so I was not concerned that the engine wasn't safe, but checking the logs got me a pretty good discount on the plane due to the actual engine time.

 

[N201MKTurbo]

I would just put it back together and call it a repair. 

[EricJ]

The threshold for "overhaul" is not really very high if the engine has already been disassembled.  Resetting the "Time Since Major Overhaul" clock just requires meeting the "overhaul" standards.   Setting the engine to "zero time" with a new logbook, as previously mentioned, is generally only done by the manufacturer.

You have a lot of options of what can be done, but "zero time" is the most difficult.  Setting it to "Zero TSMOH" is much easier. 

[kortopates]

Age in years since last OH is just as important as hours. I’d run the numbers before deciding. As a repair, the engine will be valued at most 400/2000 of a freshly overhauled engine, and perhaps a lot less if old.


Sent from my iPhone using Tapatalk

[M20F]

The only difference between IRAN and Major is selling price.  A 20,000hr since major engine that is consistently flown, IRAN, etc. is just as mechanically sound as an engine that has been overhauled 100hrs ago (removing infant mortality).  One is going to command a much higher resale value.  

[Utah20Gflyer]

At 400 hours I would IRAN the engine, above 1000 hours I would begin considering a major overhaul but might still IRAN depending on my plans with the plane.  The reason is that the value difference between a 0 SMOH engine and 400 SMOH is very little.  0 vs 2000 there is a big difference in the value which better justifies the increased cost of the Major overhaul.