Thinking about engine "wear-in" [not break-in] I have heard that engines can take a while to wear in and develop the maximum horsepower they will ever make. Is there any truth to that? If so, how long might that typically take?

Battson wrote:Thinking about engine "wear-in" [not break-in] I have heard that engines can take a while to wear in and develop the maximum horsepower they will ever make. Is there any truth to that? If so, how long might that typically take?

Engines actually make their most horsepower right before they explode. Probably not what you want.

Hahahahaaa

Thanks Phil

Battson wrote:Thinking about engine "wear-in" [not break-in] I have heard that engines can take a while to wear in and develop the maximum horsepower they will ever make. Is there any truth to that? If so, how long might that typically take?

Something must of made you ask...

Was there an indication of nothing less than full power? Where did you get the definition of "wear in" vs "break in".?

How many hours? Compression? Oil consumption? Fuel GPH? What do your spark plugs/injectors look like?

I watch engine instruments like a hawk, and recently the fuel flows are slightly higher for a given condition [e.g. 10,000ft, WOT, 2300RPM, 20 LOP].
I am seeing more airspeed too, so I feel like I am getting more power. We did just clean the injectors though, 200hrs. Plugs and cylinders are spotless as I run LOP, or lean aggressively otherwise. I have 215hrs on the engine now, compressions range from 74 to 79.
I can't recall where I read about the settling in period, probably on here somewhere

Battson wrote:I watch engine instruments like a hawk, and recently the fuel flows are slightly higher for a given condition [e.g. 10,000ft, WOT, 2300RPM, 20 LOP].
I am seeing more airspeed too, so I feel like I am getting more power. We did just clean the injectors though, 200hrs. Plugs and cylinders are spotless as I run LOP, or lean aggressively otherwise. I have 215hrs on the engine now, compressions range from 74 to 79.
I can't recall where I read about the settling in period, probably on here somewhere

Instrumentation issue (as discussed) seems to me.

Settling in is common in piston engines. Rings will continue to wear against the cylinder. The other parts will wear together and reduce friction slightly as well.

Good deal that you've noticed it!

8GCBC wrote:

Battson wrote:I watch engine instruments like a hawk, and recently the fuel flows are slightly higher for a given condition [e.g. 10,000ft, WOT, 2300RPM, 20 LOP].
I am seeing more airspeed too, so I feel like I am getting more power. We did just clean the injectors though, 200hrs. Plugs and cylinders are spotless as I run LOP, or lean aggressively otherwise. I have 215hrs on the engine now, compressions range from 74 to 79.
I can't recall where I read about the settling in period, probably on here somewhere

Instrumentation issue (as discussed) seems to me.

For clarity, this is different to the instrument problem I mentioned in the other thread.

This appears to be a continuous but very slight (>3%) increase in flow, compared to when I first starting flying the (new) engine, and is corroborated by more airspeed and slightly less fuel in the tanks over a long time period (several re-fuels).

I had heard that engines can change over the course of their life, so wonder whether that might be what I am experiencing.

Battson wrote:

8GCBC wrote:

Battson wrote:I watch engine instruments like a hawk, and recently the fuel flows are slightly higher for a given condition [e.g. 10,000ft, WOT, 2300RPM, 20 LOP].
I am seeing more airspeed too, so I feel like I am getting more power. We did just clean the injectors though, 200hrs. Plugs and cylinders are spotless as I run LOP, or lean aggressively otherwise. I have 215hrs on the engine now, compressions range from 74 to 79.
I can't recall where I read about the settling in period, probably on here somewhere

Instrumentation issue (as discussed) seems to me.

For clarity, this is different to the instrument problem I mentioned in the other thread.

This appears to be a continuous but very slight (>3%) increase in flow, compared to when I first starting flying the (new) engine, and is corroborated by more airspeed and slightly less fuel in the tanks over a long time period (several re-fuels).

I had heard that engines can change over the course of their life, so wonder whether that might be what I am experiencing.

Where did you hear it? Interesting subject.