Why is LOP (lean of peak) controversial?

Matt Barrow wrote:

What % of power are you using? I'm usually around 360-370, but I'm running
70-75%.

I also cruise around 75% of the IO-520's 285 hp.

--
Peter

"Peter R." wrote in message
...
Matt Barrow wrote:

What % of power are you using? I'm usually around 360-370, but I'm
running
70-75%.

I also cruise around 75% of the IO-520's 285 hp.

What altitude? FF?

Matt Barrow wrote:

"Peter R." wrote in message
...
Matt Barrow wrote:

What % of power are you using? I'm usually around 360-370, but I'm
running
70-75%.

I also cruise around 75% of the IO-520's 285 hp.

What altitude? FF?

In summer temperatures at 12,000-15,000 feet I get about 187-190 kts TAS at
about 15 gph. In the winter, I see 175-180 kts TAS and 16.5 gph or so.

--
Peter

Peter R. wrote:
Matt Barrow wrote:

"Peter R." wrote in message
...
Matt Barrow wrote:

What % of power are you using? I'm usually around 360-370, but I'm
running
70-75%.

I also cruise around 75% of the IO-520's 285 hp.

What altitude? FF?

In summer temperatures at 12,000-15,000 feet I get about 187-190 kts TAS at
about 15 gph. In the winter, I see 175-180 kts TAS and 16.5 gph or so.

--
Peter

Unless the LOP "formulas" have changed (which IS entirely possible,
been a few years since I had to think/worry about it) anything much
over 14.5 GPH would be considered higher than 75% power.

285 HP x .75 = 213.75 HP / 14.9 HP/G = approx 14.3 GPH @ 75% operating
LOP

If your CHT's are closer to 300 F than 400 F running those settings,
you've got one of the "cooler" installations that I've ever heard of...

TC

" wrote:

If your CHT's are closer to 300 F than 400 F running those settings,
you've got one of the "cooler" installations that I've ever heard of...

The cylinders are new Superior Millennium cylinders with about 250 hours on
them, if that has anything to do with the cooler temperatures.

And yes, my engine's CHTs are normally below or around 300 and have never
approached 400, routinely. If you would like some verification of this, I
would be happy to upload my engine monitor data (from several months ago, I
have yet to download a current set), which is in the latest JPI format, to
a free host site for anyone's perusal.

--
Peter

You more than likely have an CHT indication problem. There is no reason your
airplane should run much cooler than the fleet.

Karl


"Peter R." wrote in message
...
" wrote:

If your CHT's are closer to 300 F than 400 F running those settings,
you've got one of the "cooler" installations that I've ever heard of...

The cylinders are new Superior Millennium cylinders with about 250 hours
on
them, if that has anything to do with the cooler temperatures.

And yes, my engine's CHTs are normally below or around 300 and have never
approached 400, routinely. If you would like some verification of this, I
would be happy to upload my engine monitor data (from several months ago,
I
have yet to download a current set), which is in the latest JPI format, to
a free host site for anyone's perusal.

--
Peter

karl gruber wrote:

You more than likely have an CHT indication problem. There is no reason your
airplane should run much cooler than the fleet.

On all six probes? That seems a tad unlikely. Additionally, are you
really in a position to speak for the fleet?

In any regard and given the responses here, I have a call in to Tornado
Alley Turbo's director of maintenance. If anyone will have the most
accurate response, it will be this person. When I receive a response I
will post it here.

Oh, I just remembered that I had sent TATurbo my JPI data file after the
first 50 hours on this rebuilt engine, sometime late spring 2004. They
responded that all data points (including the CHTs) looked well within
accepted ranges. Had they had a concern about CHTs, that would have been a
perfect opportunity to raise it with me.

--
Peter

Peter R. wrote:
" wrote:


If your CHT's are closer to 300 F than 400 F running those settings,
you've got one of the "cooler" installations that I've ever heard of...


The cylinders are new Superior Millennium cylinders with about 250 hours on
them, if that has anything to do with the cooler temperatures.

And yes, my engine's CHTs are normally below or around 300 and have never
approached 400, routinely. If you would like some verification of this, I
would be happy to upload my engine monitor data (from several months ago, I
have yet to download a current set), which is in the latest JPI format, to
a free host site for anyone's perusal.


Is your JPI set up for the correct probe type? Your CHTs sound awful low

Ray Andraka wrote:

Is your JPI set up for the correct probe type?

Could you expand on this? I do not know the answer and if this might be
the case, I would like to be able to approach my mechanic with an educated
question.


--
Peter

Peter R. wrote:
" wrote:

If your CHT's are closer to 300 F than 400 F running those settings,
you've got one of the "cooler" installations that I've ever heard of...

The cylinders are new Superior Millennium cylinders with about 250 hours on
them, if that has anything to do with the cooler temperatures.

And yes, my engine's CHTs are normally below or around 300 and have never
approached 400, routinely. If you would like some verification of this, I
would be happy to upload my engine monitor data (from several months ago, I
have yet to download a current set), which is in the latest JPI format, to
a free host site for anyone's perusal.

--
Peter

I'm not doubting your numbers-but am not sure if the LOP people are
still using 14.9 HP/G. Sounds to me like you've got an engine to hang
on to.

If you could spare the extra weight, I'd consider adding a pre-oiler
and flying that engine as long as I could...

Regards;

TC