O vs IO

[Archammer]

Definitely IO for me... even with a 200 hp 4-cyl. The fuel savings are substantial, but more important is the ability to manage CHT's and keep the engine clean internally by not dumping extra fuel through it.

That's where the real savings are with running LOP, valve and cylinder costs.

That's exactly what I was after right there. Even in the 4cyl, the benefits are still substantial. I agree that the cleaner run of the engine is paramount, and unfortunately we humans are not very efficient at it. That's why I love the FADEC systems.

 

[Ted]

Thanks Ted and others, ok, the heads flow better. That said, I've never heard of a 200hp O-360 Lyco, does one exist or are they all injected?

All of the angle valve 360/540s are injected. I suspect it likely had to do with cruise leaning.

 

[Ted]

That's exactly what I was after right there. Even in the 4cyl, the benefits are still substantial. I agree that the cleaner run of the engine is paramount, and unfortunately we humans are not very efficient at it. That's why I love the FADEC systems.

Funny, the exact reason I don't want a FADEC is because a properly trained human is remarkably difficult to replicate with software, and the FADECs don't do a great job of it. The common comparison to automotive ECUs is not a good one.

 

[jsstevens]

Funny, the exact reason I don't want a FADEC is because a properly trained human is remarkably difficult to replicate with software, and the FADECs don't do a great job of it. The common comparison to automotive ECUs is not a good one.

Automotive ECUs have given us remarkable increases in efficiency because autos run in almost continuously varying conditions.

Aircraft operations are almost perfect for manual operation-get to altitude, set up for cruise, leave alone for hours. They can be optimized for cruise performance in things like cam timing, spark timing and induction. We adjust the mixture and voila-optimum operation.

The payback for FADEC isn't really there.

John

 

[Ted]

Automotive ECUs have given us remarkable increases in efficiency because autos run in almost continuously varying conditions.

Aircraft operations are almost perfect for manual operation-get to altitude, set up for cruise, leave alone for hours. They can be optimized for cruise performance in things like cam timing, spark timing and induction. We adjust the mixture and voila-optimum operation.

The payback for FADEC isn't really there.

John

You got it spot on accurate, John.

 

[Aaronk25]

Agreed.....manual mixture will let a pilot get better efficiency than fadec....take for example the Porsche Mooney, it never got better mpg than a current Io360 200hp.

In a car FADEC makes sense as the power settings are always changing, in a plane as we know it's stays steady most of the time.

 

[Ted]

take for example the Porsche Mooney, it never got better mpg than a current Io360 200hp.

There are other factors there, though. A high-RPM geared engine with overhead cams and a less aerodynamic cowling had a lot to do with that.

Put a FADEC on a traditional engine, put me in an identical mechanical plane, and like John Henry I'll beat the machine, or at worst tie it.

 

[schmookeeg]

I've been watching this one:

www.americanpropeller.com/ignition.htm

Since I have prop de-ice I need ones with the mag timing housing, but if you can put a slip ring on you can have a 6-cylinder unit today. When I talked to them about 6 months ago they said they were working through some cert hurdles and it should be a few more months. It's been more than a few now, but we all know how certification goes...

I've been considering this as a testbed for us to install -- what sort of "before/after" tests would you suggest to gauge its efficacy on an IO-550? I have a G3 analyzer so I can get some reasonable data pre- and post- install.. the claims they make are... aggressive.

 

[Ted]

I've been considering this as a testbed for us to install -- what sort of "before/after" tests would you suggest to gauge its efficacy on an IO-550? I have a G3 analyzer so I can get some reasonable data pre- and post- install.. the claims they make are... aggressive.

I would establish speeds for a given RPM and LOP fuel burn before and after. Make sure to record OATs and use a constant weight.

I think what you're really going to find will be just knowing what your plane does before and after. If you don't have an ADAHRS of some sort, you probably will have a hard time getting TAS differences noted. With the Aspen, I can actually see differences of 1-2 MPH. With the steam gauge, I need 5 to really discern.

I also think the speed differences will be difficult to notice unless you fly 10 hours in a day like I do.

 

[schmookeeg]

I would establish speeds for a given RPM and LOP fuel burn before and after. Make sure to record OATs and use a constant weight.

I think what you're really going to find will be just knowing what your plane does before and after. If you don't have an ADAHRS of some sort, you probably will have a hard time getting TAS differences noted. With the Aspen, I can actually see differences of 1-2 MPH. With the steam gauge, I need 5 to really discern.

I also think the speed differences will be difficult to notice unless you fly 10 hours in a day like I do.

The before and after is what I want... I am not doing it for the speed claims, we have a business reason for getting one... (we're one of their approved install shops) -- but the 10-15% claims will need substantiation or refutation.. and I'd like to be able to intelligently answer when the questions come... plus I'd like my own set of facts about suggested installation time before we get thrown under the bus... been there a few times.

We have the same suspicions about the end result.

 

[Ted]

On the 310, my thought is if I get an extra 3-4 kts at higher altitude, I'll be satisfied. If I can get 5-7 kts, I'll be ecstatic.

 

[JHW]

On the 310, my thought is if I get an extra 3-4 kts at higher altitude, I'll be satisfied. If I can get 5-7 kts, I'll be ecstatic.

the experimentals I've flown with electronic ignition seem to tell me that the savings are in fuel, not speed. With the big timing advance at reduced MAP (cruise in your NA engines) you can lean further without misfire.

 

[Ted]

the experimentals I've flown with electronic ignition seem to tell me that the savings are in fuel, not speed. With the big timing advance at reduced MAP (cruise in your NA engines) you can lean further without misfire.

That's the other side, and if I can save 2-3 gph at the same speed, I'll be satisfied. If I can save 4-5, I'll be ecstatic. 23-27 now.

 

[Henning]

Arnt you cute.....

Aren't you an idiot.

 

[JHW]

That's the other side, and if I can save 2-3 gph at the same speed, I'll be satisfied. If I can save 4-5, I'll be ecstatic. 23-27 now.

I'm doing to do it on my travel air, just not sure when. I already moved things around in the nacelles behind the firewheels, to have a spot for the computer next to the voltage regulators. There a a few trips we make regularly that I could eliminate a fuel stop with a small % improvement in mpg

 

[Henning]

That's exactly what I was after right there. Even in the 4cyl, the benefits are still substantial. I agree that the cleaner run of the engine is paramount, and unfortunately we humans are not very efficient at it. That's why I love the FADEC systems.

As long as I still have the red handle to vary the algorithms of the FADEC to respond appropriately, kind of like fly by wire does, then I'm ok with FADEC, especially if I get it in a Direct Injection format.

The thing is I want it to respond differently according to a changing multi variable equation, and it can't know what I want, so the programming can't be optimized for that phase of flight without me being able to give it a command input. The red handle is a much better way for me to give that command than a keyboard in a dynamic environment.

The part I do want from FADEC is the electronic ignition and knock sensor with automatic retarding. That's plenty good for me. I can set the mixture on a mechanical system to do what I want just fine, let the computer optimize the ignition to match my inputs and I have an excellent system that I can get well within the point of diminishing returns in efficiency over adding a Direct Injection system, much less a TPI system. Yeah, I pick up some fuel pattern efficiency with the HP Electronic system, but with a 2 plug system that advantage is mitigated some. If it was 'plug and play' and a couple of thousand, I would replace factory FI. I'd probably give $5-$7k to upgrade an O engine though. But it would have to be easily operationally tunable to be considered.

 

[Ted]

I'll be curious to hear your results. I'll not eliminate a fuel stop with a small change in economy for my normal trips, but for the typical use the plane gets, the fuel savings will add up.

 

[Henning]

The before and after is what I want... I am not doing it for the speed claims, we have a business reason for getting one... (we're one of their approved install shops) -- but the 10-15% claims will need substantiation or refutation.. and I'd like to be able to intelligently answer when the questions come... plus I'd like my own set of facts about suggested installation time before we get thrown under the bus... been there a few times.

We have the same suspicions about the end result.

Well, now you have an excuse to get a G-500 for your test bed, you can write it off even.

 

[schmookeeg]

Well, now you have an excuse to get a G-500 for your test bed, you can write it off even.

Heh. Writeoffs require profits to offset first

Still have KX-170s in my S35. A G500 would look real silly next to those coal-powered radios. Like putting a plasma flat panel inside of a wooden console on the floor.

 

[Henning]

Heh. Writeoffs require profits to offset first

Still have KX-170s in my S35. A G500 would look real silly next to those coal-powered radios. Like putting a plasma flat panel inside of a wooden console on the floor.

Well, then add a GTN 750 to drive it. Gotta have accurate data for test runs. (although a GNS400 would be adequate.)