Piston engines- The REAL story.

[Chimbu chuckles]

This is the URL to a series of articles written by a very clever fella by the name of John Deakin.

John is an extremely experienced and interesting bloke and he is certainly passionate about his flying and particularly piston engines.

As you will see, this information is backed up with real science and he uses it in his own aeroplane.

I too own a Bonanza (A36, VH-EZU) and have just had it's first life IO550B engine overhauled with new Millenium Cylinders and have had fitted an EDM700 and Gamijectors. In the future anyone flying my aircraft, it will be online at YRED Aeroclub, will be expected to understand the concepts within these articles and operate the aircraft accordingly. With John's permission I printed his articles on Mixture etc and the CFI and his staff Instructors are all devouring the information and looking forward to putting it into practice in EZU...as am I in a few days when I pick it up from the overhaul shop.

Woomera has asked me to start this thread and monitor it, which I'm only to happy to do. I will of course be posting the results of my own experience with this new technolgy in my own aircraft.

At this point it's prudent to add a few caveats,

1/. The concept of Lean of Peak (EGT) operation in modern flat 6s is only possible with this technolgy installed and a good understanding of the concepts. If you're flying carbureted engines tough luck.
2/. What your CP/CFI says overrides anything in these articles as far as aircraft/pilots under his charge are concerned.

Having said that there is a vast amount of plain old 'Good Airmanship' in these articles too...the sort of stuff every new CPL holder should know and practice anyway.

You will learn vastly more in these articles than you ever did in PPL/CPL 'Engines, Systems and Instruments' courses...I did!

When you have read and absorbed these articles you WILL have a greatly expanded knowledge of how the engines fitted in virtually all the piston powered aircraft operated commercially in the VFR/IFR Charter fields in Australia function, whether Lycoming or TCM, Turbo or Normally aspirated.

This stuff really does apply to every C210/Bonanza/C310/Baron/Chieftain etc and even if they are not fitted with the requisite technology you'll learn what NOT to do to the engines which only have the basic, 'standard fit', almost shamefull lack of engine monitoring.

While John is a very, VERY busy man if this thread draws sufficient interest I'm sure I can convince him to make some personal appearances to answer questions that I may not be able to.

http://www.avweb.com/articles/pelperch/pistonlinks.html

Enjoy:D

Chuck.

[Bevan666]

I have a great deal of time for John and the articles he writes. With your engine monitor do you have the ability to log what others do in flight? If so you have an excellent tool to keep the other users of your aircraft honest.

Of the nanza's I fly, only one is fitted with GAMIinjectors, and none have anything more than a single probe EGT, which unfortunately precludes using LOP operation. (plus it is not sanctioned by the owners so also a no-go)

There is so much fud and old wifes tales around about correct piston engine operation. Its really good to see a lot of independant work being done by gami and a few old hands trying to show us the way.

I think a fellow by the name of Bill Finlen could be of some assistance too, Chimbu. He owns a vtail at Archerfield and recently visited the folks at gami on his recent round the world flight. He flew that all using LOP operation with no ill effects as well.

When you get a moment, post some fuel flow/tas figures - I'd love to get a feel for the sort of fuel savings (and range increases) you are getting.

Bevan..

[Blue Sky Baron]

Well Chuck,

You have really opened up a huge can of worms here!!

The LOP issue is quite complicated and oh so IMPORTANT for any piston engine operator to UNDERSTAND.

The Australian Bonanza Society recently held a BPPP (Bonanza Pilot Proficiency Program) at Coffs Harbour and as part of that program we invited Thomas Turner from the USA to make a presentation to our members on several issues regarding operating our aircraft and one of his major topics was LOP, yes or NO!

You can read an article written by Thomas at: www.abs.org.au follow the "Newsletters" link to page 8 of September 2002.

You will find this article very interesting and I have to say I'm now convinced beyond ANY doubt that the only way to run my IO-520's is 75 degrees RICH of peak.

I look forward to meeting you at Longreach this weekend and I'll have a membership form in hand for you!! :eek:

No doubt there will be LOTS of further discussion here to follow.

Regards,

BSB

[Bevan666]

Just read the article in question on the abs web site. Doesnt really go into too much detail, unfortunately. He especially didnt mention how all temperatures are far cooler in the LOP range. (Especially CHT, and thats what burns valves...)

As far as I can ascertain, the arguments for LOP are;

- everything runs cooler

- on non-turbo engines there is no risk of detonation under 75% power

- with accurate fuel injectors, there is a more even fuel distribution which gets away from the problem of cylinders peaking at different times. (and inadvertantly running them at peak EGT/CHT)

I look forward to more installments in the leaning debate...

Bevan..

[Chimbu chuckles]

BSB,

Well I read that but have to say that I can't comment much until I've read what he has to say next.

So far what he has to say pretty well agrees with everything that John has had to say, from a technical perspective at least. I note he makes the point that GAMI have done more research than virtually any other company...including TCM!

I presume you have closely studied John's Mixture Magic column?

If your aircraft is not fitted with GAMIjectors AND some sort of individual CHT/EGT monitor then I absolutely agree that an IO520/550 should be run around 80 to 100 ROP least some cylinders be left in the peak CHT zone.

It was my perception that he was somewhat disparaging about the requirement to fit new technology as a way of using the 'new way' of leaning:confused: How can any technology that allows a fuller understanding of what's going on inside the engine be bad...why hasn't TCM bought out this technology decades ago?

I don't agree that LOP is 'new' in general terms...just new to flat engines.

Anyway all my knowledge of LOP is theoretical so far...tonight I'm hopping on a bus to Scone to pick up EZU. By tomorrow evening I will have made my first BMP (Big Mixture Pull) and be able to post here in a far more informed way. By Friday evening, when I reach LRE I'll have 6 or 8 hours of experimenting with LOP operations. At this point in time I have NO DOUBT that this will be good.

Ron Koyich warned me that the ABS would be resistant to this;):D

Chuck.

[Blue Sky Baron]

Bevan/Chuck,

Unfortunately part 2 of the article will not be published until the December ABS magazine, but not to worry Chuck, you'll be a member by then :D ;) so you will get your copy!!

Thomas was quite a believer in "New Technology" during his presentation although this may not come through as clearly in the article.

Regards,

BSB

[Chimbu chuckles]

Hey BSB..got any formation flying experience...I'd kill for some good in flight piccies of EZU...I have a digital camera and formation endorsement/experience if you're up for it on Saturday afternoon:D



Chuck.

[gaunty]

BSB

Why am I not surprised that the Bonanza mob are coming down on the ROP side, they Beech 've been stuck in a time warp since Walter, Olive and their Chief Designer (I cant rmember his name for the moment) got heir heads together about the way airplanes should work. Which is why Beech now belongs to Raytheon.
BTW It's interesting Walter Beec and Clyde Cessna used to work together and actually built their original models themselves, Bill Piper was an investor who bought a design (the Taylorcraft to become the Cub) and employed people to do so and the subsequent histories and fortunes of the companies they founded pretty much followed that track.

I look forward to discussing this further with you at LRE.

Chuckles
What most seem to have missed in this temperature bit is that running LOP means that there is LESS excess fuel, if at all ANY available to contribute to the heat producing process. For example in this condition if you have a dodgy injector it can only get even leaner NOT richer and as you are past the Peak already can therefore only get cooler.


Running leaner from there (LOP) it can ONLY get cooler towards extinction , running richer i.e. towards Peak only runs to the same point as running ROP only from a different direction.

However coming from the ROP direction there is heaps of fuel just waiting for the right conditions, i.e. our dodgy injector again, except in this case, as we are ROP we head towards Peak, which is exactly what we are tring to avoid.

Ergo LOP is "safer"??

In simple terms, or to my simple mind anyway;
A turbine engine runs in an "excess of air'" environment and fuel is added or subtracted to adjust the temp.
A piston engine runs in an "excess of fuel" environment and we adjust the amount of air we make available to adjust the temp, hence the use of the term throttle".

Running a piston LOP could be analagous towards the turbine mode, if you know what I mean.:confused:

Or am I just flapping my gums again. :D

[High Altitude]

QUESTION.

Reading all of the info is brilliant. Well done guys.

My question is how would you go LEGALLY operating not in accordance with the POH?

What would be the ramifications if you crashed and were proven to be operating the aircraft not in accordance with the POH?

From the U206G book :-

"For best fuel economy at 65% power or less, operate at 1 gph leaner than shown in this chart or at peak egt if egt indicator is installed"

"Recommended lean mixture, cowls closed"

FROM THE 310R 1979

"Operations at peak egt may be utilized with power settings within the boxes if the airplane is equipped with the optional egt system"

[Chimbu chuckles]

LRE IS GUNNA BE FUN!!!:D

Hey Gaunty you can be my safety pilot if we launch for some piccies.

BSB if you haven't seen the GAMIjectors and EDM work together we can launch and I'll show you what I've found first hand between tomorrow and LRE.

As you can see...any excuse to get off the ground.:D

I was terribly disappointed to see my new AFM when it arrived was a black tome with Ratheon written on it:( Lucky I also have an older Beechcraft Blue one as well to keep at home:D

HA,

It seems like the POHs are written with a Lawyer looking on so that they are presented in such a way as to protect TCM/Ratheon from even the dumbest pilot. I think ample evidence exists within Johns columns to prove that you're not hurting the engine at all...quite the contrary.

Mr Thomas' article, to be convincing re anti LOP operation, better have some real time recorded data, such as we get from John's EDM...and soon mine or else, as far as I'm concerned, it's just following 'the company line'.

Chuck.

[Blue Sky Baron]

Chuck,

I'll be there with formation endo & digital camera so I'll be in it anytime. :p

Keep the old AFM, it probably has more useful info than the new one. :confused:

Why didn't you get the work done at Redcliffe?

Gaunty,

I wondered how long it would be before you entered the debate!!!!:p

So I guess you know what it was that Wally & Clyde built together ;) - not hard to see who had the most influence in the design. :D

BTW Gaunty, what red would you prefer I bring, Cabernet or Merlot? :cool:

BSB

[gaunty]

BSB

I keep looking but so far haven't found a low wing bird.:D and after the second or third bottle you may be able to get me explain why the big uns are low wing. Though I warn you the "window" during which this is possible with any degree of coherence is quite narrow.:rolleyes: :eek:

Q: Re Cab or Merlot?

A: = Yes please. :p :cool:

[Blue Sky Baron]

Gaunty old Buddy,

I believe the TRAVELAIR is a low wing!!! :eek:

BSB

[gaunty]

Yeah! I meant the feathered variety, and by biguns the twins.:D

[Icarus2001]

Hey Chimbu, that wasn't you forgetting to cancel Sartime at Redcliffe today was it?

[Chimbu chuckles]

Yup...mea culpa...I was fried.

What a last 24 hours I've had:eek:

1/. I will NEVER travel interstate by coach again..11 hours in the damn bus and 20 minutes sleep if I'm lucky
2/. 2 test flights at SCO..the first with radio probs but the second was good. Thanks to Mick, Paul and Eric at Scone Aircraft Maintenance for getting me away and for a job well done on my aeroplane.
3/. A two hour flight SCO-MSO-Walcha-PLO-LVA-YRED that turned into 2+20 due storms...about 75% of the trip I had turbulence and about 30% was a real wild ride..including hitting my head on the roof twice, once while talking on the radio:D
4/. A last 30 minutes marred by finger trouble on the GPS and then a 20kt straight crosswind at YRED.

Family there to pick me up and I just completely forgot my SARTIME until the batphone rang while driving home...bloody lucky I didn't get pinged by a copper...would have been par for the course today:(

Besides that's the F/O's job and I didn't have one:D

Now for the good news. Below is a link to a not very good piccy of my EDM700...about mid wild ride.

With the exception of climbing LOP (it was just too bumpy to dick around) I conducted the flight as per John's Mixture Magic and Putting it all Together articles.

1/. Climb at 120KIAS, Throttle wide open, full rich, 2500RPM.
The CHTs remained way under 380 the whole way to 7500'.
2/. Levelled off, accelerated, closed cowl flaps.
3/. Didn't do the 'Big Pull':D 'cause it was too bumpy...did a steady wind instead.
4/. All the EGTs marched upwards in perfect step and then fell down the lean side of peak. Smooth as a baby's botty.
5/. A few tweaks had #4 CHT steady at 375 give or take a bit due to IAS fluctuations.
6/. TAS 160ish, 49 LPH.
7/. 49LPH LOP= 12.9 USG/Hr= 192 BHP=64%.
8/. RPM stayed at 2500 until mid descent when I wound it back to about 2100 to control speed, then pulled MP back for the first time since applying takeoff pwr at SCO. Mixture I only tweaked in cruise and then went full rich on base.
9/. The other 5 cylinders varied from 330 odd to 360 odd with corresponding lower EGTs than that in the piccy.

It's easy and it works!!

Chuck.

http://www.fototime.com/{C0EF217E-34EA-4888-95C9-FEC87D861808}/picture.JPG

[Icarus2001]

Unlike your link!:( Don't keep us in suspense.

Also...2/. Levelled off, accelerated, closed cowl flaps.

Not in that order surely?

I know don't call you surely...

[Chimbu chuckles]

Fixed.

Icaarus were you the nice man on the phone from CB?:o

Chuck.

PS. Yes that order.

[Icarus2001]

Negative on the phone idea. Nice guess though.;)

Why not close the cowl flaps prior to or on reaching TOPC if the temps are in the right spot?

[Chimbu chuckles]

It's just a 'do everything to keep them cool' thing.

Next time I'll try closing just prior to TOPC...there is a school of thought that suggests you can't get them fully closed once air pressure builds up in the cowl...but they seemed to snick home nicely.

Hopefully YRED-LRE will be a more pleasant flight...and I will remember to cancell SAR.

Chuck.

[Sheep Guts]

Hey Guys,
It all sounds good, but what about the Whyalla Airlines incident with the Chieftain. Wasnt that found to be the fault of running LOP for thousands of hours.....

Regards
Sheep

[Chimbu chuckles]

Different engine from mine for starters but go to the link in the first post and look down the bottom for some articles on the Whyalla Airlines crash. Right or wrong...and I know what I think..they make for interesting readin, particularly in light of the recent Lycoming engine recalls etc.

The only risk from operating 'around peak' without knowing what's going on from something like an EDM700 is to the cylinders that are just on the rich side...not those that are just LOP EGT.

Chuck.

[...still single]

I've been in an engine failure -back piston in a TSIO 520 melted. It was run at 25 square and 50f rich of peak, but without a JPI, who knows what was happening in that pot? After reading J. Deakins articles, I'll be changing my engine management technique.:eek:

[Chimbu chuckles]

In the last week I've done 14 odd hours in my IO550b powered Bonanza with the EDM 700/Gamijectors...I can only endorse what John says..it works.

On the Bne-LRE-Bne trip over the weekend just passed I was able to demonstrate to 3 pilots, 2 experienced in Bonanzas and one fella currently doing his PPL, exactly how it works in practice.

Jamair made the statement to all after this flight that in his opinion, "If you fly these aircraft without this technology you're mad"...or words to that effect:D

Chuck.

[Mainframe]

Chimbu

You have committed an unnatural act !
Don't you remember, back when we both learnt to fly, that you were FORBIDDEN to even think about touching the mixture control below 5,000'.

For this act of heresy, you are likely to be burned at the stake, or weighted with stones and thrown in a river to see if you float.

Great stuff, with the correct techniques and the right gear installed, bring on LOP !

Sheepguts

Don't get too confused about Whyalla.

The ATSB used the emotive term "aggressive leaning" techniques to describe the technique the manufacturer outlines in the user manual.

Yes, the company had a record of achieving more than full life from their Lycoming factory remanufactured engines.

This would indicate that the manufacturers technique is valid.

Lycoming has a problem with TIO 540 engines since they changed ( removed lead for the Greenies ) the metal composition of bearing shells. They have also other A/D's emerging on their engines. Whyalla used factory engines.

The articles available on LOP ( US AOPA etc ) confirm LOWER cylinder operating temperatures when LOP procedures are understood and complied with.

Peak EGT and just rich of peak seem to produce the highest temperatures according to research described.

In summary optimum leaning should be employed at less than 75% power, using either the manufacturers methods, or by installing balanced injectors and multi probed EGTs and CHTs.

With the latter, the suppliers techniques and limitations should be observed.

In reality, this is not an Unnatural Act and is how FADEC operates.

Users of TCM engines should ensure that the applicable SB relating to fuel pressures and fuel flows is carried out several times after engine O/haul or fuel system component change.

[Jamair]

Chuck:

Can't recall - does your JPI have fuel calculations built in, ie time to empty et al?

I am in the process of ordering one and need to tie all the gizmos together in the most economic way......

Would also be interested to see the graphs from the lRE trip if you have downloaded them, to compare with JDs data.

Cheers, MSR

[Chimbu chuckles]

Yes it has the fuel computer add on option with fuel flow/fuel used/remaining/time to utter quiet etc. I think it was about AUS$1400 on top of the cost of the basic EDM700...naturally if you're buying one for a twin it will be doubleish as two transducers etc.

Very nice knowing to within a litre what's in the tanks...EZU's gauges are a joke...like most piston aircraft. For instance burn 70 lt out of the left tank (which is half the useable therefore close to half the total) and the gauge says 3/4 full :rolleyes:

It just makes all the sense in the world to have both capabilities in the one instrument...and in the case of EZU a stand alone fuel flow thingy was about the same price or a little more than the cost of the add on for the EDM.

No I havn't...I should pull my finger out and do it...all that's slowing me down is the battery in my laptop has developed a memory or is fried for some other reason so it only works when plugged in as per desktop.

Chuck.