How Much Do You Want to Know About How to Operate your Lycoming

[PT20J]

1 hour ago, dzeleski said:

Not the cars ive worked with, and ive worked with hundreds. Most under load are running 12-13:1 , and 15-17:1 at highway loads. Back in the 90s honda was running their early fuel injection setups at like 18-20:1, but we then figured out that was causing worse emissions then at 15-17:1. During cold start yes, this warms the cats faster for emissions reasons.

Well, all I can say is that all textbooks I have say that street engines run stoichiometric most of the time because that minimizes emissions and maximizes conversion efficiency of three way catalysts. Indeed, the purpose of the oxygen sensor is to let the ECU set this A/F ratio. Engines run richer at idle because the scavenging of exhaust gases from the cylinder is poorer and also run richer during acceleration and higher loads to maximize power. But cruising down the highway at part throttle the engine is loafing. Here's a non-technical reference from a website geared for engine tuners: https://www.innovatemotorsports.com/resources/small-block-chevy.php#:~:text=All new cars run at,part throttle to gain mileage.

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[A64Pilot]

Way back in I believe the mid or late 70’s several cars did run lean, Chrysler had their “Lean Burn” engine and I forget what Honda called theirs but they had one too.

‘However pretty quickly exhaust emissions killed lean burn engines due to their high combustion temperatures caused excessive NOX emission I believe, this was also about the time that EGR came into use as EGR reduces exhaust temps and therefore NOX, that’s the purpose of EGR, to reduce combustion temps 

However lean burn may make a comeback as it can in fact reduce fuel consumption, currently I know Suzuki Outboards that are fuel injected will go into lean burn in the middle third of the operating RPM, they can’t at low RPM as the combustion is unstable and the engine runs rough, and they can’t at high power as excess fuel is needed to cool the combustion chamber, but the middle third where most cruising is usually done, they do and burn less fuel, but they don’t have to pass the emissions an automobile does apparently.

Now with variable valve timing, and even variable displacement and variable compression ratio, there is no telling what’s coming,if development continues.

‘In particular Mazda is building a gasoline fueled Diesel engine, sort of, and ALL Diesels are lean burn as they don’t throttle air at all, every stroke brings in a full cylinder of air, only fuel is throttled in a Diesel, and that’s about as lean burn as you can get, sort of the poster child for lean burn

The Toyota Prius is or was about the pinnacle of spark ignition engine efficiency, and it’s not a lean burn motor. However it’s not an Otto cycle engine either, it’s an Atkinson cycle engine, which is a VERY old design and with the advent of digital engine controls has finally become viable, well that and a parallel electric motor, although since the Prius motor many other manufacturers have part time Atkinson cycle engines now.

‘In short lean burn is a tiny drop in the bucket of what’s going on auto technology wise, question is, will development of the ICE stop due to the rage in electric vehicles?

Edited March 16, 2021 by A64Pilot

[A64Pilot]

https://en.wikipedia.org/wiki/Atkinson_cycle

[dzeleski]

32 minutes ago, A64Pilot said:

Way back in I believe the mid or late 70’s several cars did run lean, Chrysler had their “Lean Burn” engine and I forget what Honda called theirs but they had one too.

‘However pretty quickly exhaust emissions killed lean burn engines due to their high combustion temperatures caused excessive NOX emission I believe, this was also about the time that EGR came into use as EGR reduces exhaust temps and therefore NOX, that’s the purpose of EGR, to reduce combustion temps 

However lean burn may make a comeback as it can in fact reduce fuel consumption, currently I know Suzuki Outboards that are fuel injected will go into lean burn in the middle third of the operating RPM, they can’t at low RPM as the combustion is unstable and the engine runs rough, and they can’t at high power as excess fuel is needed to cool the combustion chamber, but the middle third where most cruising is usually done, they do and burn less fuel, but they don’t have to pass the emissions an automobile does apparently.

Now with variable valve timing, and even variable displacement and variable compression ratio, there is no telling what’s coming,if development continues.

‘In particular Mazda is building a gasoline fueled Diesel engine, sort of, and ALL Diesels are lean burn as they don’t throttle air at all, every stroke brings in a full cylinder of air, only fuel is throttled in a Diesel, and that’s about as lean burn as you can get, sort of the poster child for lean burn

The Toyota Prius is or was about the pinnacle of spark ignition engine efficiency, and it’s not a lean burn motor. However it’s not an Otto cycle engine either, it’s an Atkinson cycle engine, which is a VERY old design and with the advent of digital engine controls has finally become viable, well that and a parallel electric motor, although since the Prius motor many other manufacturers have part time Atkinson cycle engines now.

‘In short lean burn is a tiny drop in the bucket of what’s going on auto technology wise, question is, will development of the ICE stop due to the rage in electric vehicles?

Its possible the latest cars are running closer to 14.7 as I have not been in that scene for about 5 years now. My 2017 runs around 15-15.5 or so at 60 in 6th. Mid 2000s cars ran leaner then that.

The Prius engine isnt a true atkinson engine. Its actually an otto cycle design with simulated atkinson mode which is made possible by VVT. Almost all toyotas including my tacoma can enter into simulated atkinson mode by using this technique.

https://mag.toyota.co.uk/toyota-use-atkinson-cycle-engines/

https://news.pickuptrucks.com/2015/01/how-it-works-2016-toyota-tacomas-atkinson-cycle.html

I think our power grids have no where near the capacity required for everyone to switch to electric. One day for sure, but I think we are a few decades away before ICE development is considered a waste of time.

[carusoam]

Does anyone have a feel for the cost of fueling an electric car?

Take an ordinary Tesla.... go 300 miles... fill the tank of electrons... what does it cost?

My neighborhood Tesla friends don’t seem to know/care or want to tell their secret...  

I could put some solar collector on my roof and power my car... that would have an interesting payback...

Is it too soon to ask?

-a-

[Jerry 5TJ]

3 hours ago, carusoam said:

Does anyone have a feel for the cost of fueling an electric car?

My Tesla 3 gets about 3.8 miles per kilowatt hour.  The Nissan Leaf about 4.3 miles per kWh.  

[201er]

In my personal opinion, the value of a plane without logs is whatever that plane would be worth with the worst case scenario of what would have been in those logs minus another 20-50% for the hassle. Solely discounting the plane by the potential expenses to be incurred fixing everything that is missing in the logs isn’t enough. You could be in for a lot of down time and hassle trying to inspect and/or fix all those things. That should be reflected in the price as well.

[1964-M20E]

The military does still have a need and use for reciprocating engines in drones.

[A64Pilot]

On 3/17/2021 at 1:31 PM, 1964-M20E said:

The military does still have a need and use for reciprocating engines in drones.

Very few actually.

‘My Company made the power levers that are used in the Predator B or “reaper” which uses a Honeywell G10 turbine, the old piston predator is pretty much retired, my be all gone I don’t know. So I could infer about how many Predator B’s were being built by how many power levers we sold, and it’s a lot more than I thought.

Lycoming did build a spark ignition jet fuel engine for some kind of drone as the Military has been one fuel forever, the last use of gasoline in the Army was the cook stove, and it went away in the 90’s? Replaced by I’m sure one that burns JP-8, which is Jet-A. The Lycoming motor is some kind of small motor I think.

https://www.lycoming.com/engines/el-005

‘Mercury outboards also built a spark ignition outboard that burns jet fuel, likely JP5 for special ops, as gasoline is not at all what the navy wants onboard,

http://www.marineenginedigest.com/profiles/mercury/Mercury-Optimax-Military-Motor.htm

in fact before I could conduct carrier quals in an AH-64 long ago we had to burn three tanks of JP5 through the aircraft before we were allowed aboard, even Jet-A is too explosive for them, gasoline is an absolute no-no

[carusoam]

@Sandman993,

have you seen a JP5 jet fuel burning Mercury engine before?

See A64’s link above...

-a-

[Sandman993]

On 3/18/2021 at 10:52 PM, carusoam said:

@Sandman993,

have you seen a JP5 jet fuel burning Mercury engine before?

See A64’s link above...

-a-

My guys loved the opti... that was one reason I wanted to be a Merc dealer when it was much easier and cheaper to go with another brand. That was a long time ago.
Our service manager is in his early 50’s, his first ever and only job was Mercury. Unfortunately, they retired the opti in the US, transferred their efforts to the four stroke. Over the years, I believe they have a winner... quiet, smooth and high output. All the new technology comes at a price.
 

like you once said... if he gives you advice, listen carefully and write as fast as you can!