GAMIjectors for Lycomings

[TLSDriver]

I have about ten hours on my new Bravo.  It is equippmed with Gami injectors and an JPI EDM-700.  I feel comfortable with the operation of the plane with the exception of leaning.  Here is what I have heard\seen so far:

1) The instructor that transitioned me said not to overthink it.  He said lean until engines loses power and the egt peaks and starts to come down.  Then enrichen about 100 degrees.

2) Mike Bucsch said that isn't a good idea.  He advocates leaning by CHT and being LOP.  He says his engines are 900 over tbo and still happy.   http://www.avweb.com/news/savvyaviator/savvy_aviator_59_egt_cht_and_leaning_198162-1.html

3)  Finally, there are the  'gami guys' that seem to use the EDM-700 or 800's.

I have been using method one but seem like I am burning a ton of gas.  I tried method 2 and actually was using even more gas! (but I was ROP and not LOP so probaly wasn't reallly doing it like Mike was.  I was trying to get my CHT to 380 but I had to run real rich to get there.  (Mehod 1 seems to be about 400 degrees CHT.)

Today I tried to use the EDM-700 in Lean of Peak mode.  I got the lean of peak message on the EDM.  The problem was as I continued to lean the engine got real rough, real fast.  My PAX got nervous so I went back to ROP ala method 1 above.  I did see the fuel burn go from 20-21 to about 18 but like I said the engine sure wasn't happy.

So a few questions for the guys flying these Lycommings in their Bravo's:

1)  How are you leaning them?

2)  The gami's were installed about 5  years ago.  Do they require service from time-to-time?  Unless I am really doing something wrong this engine didn't want to be LOP at all.

3) A friend of mine said forget LOP on a Lycomming.  It just wont work.   I don't know if I am 100% in on that since the people at GAMI seem honest and I can't imagine they would see a product that wont work on these engines.  So the guestion is could it be that some of these engines won't go LOP or it likely a GAMI tuning issue?

Any ideas on leaning my bravo will be appreciated.

 

David

 

 

 

 

[KLRDMD]

Quote: TLSDriver

 A friend of mine said forget LOP on a Lycomming.  It just wont work.   I don't know if I am 100% in on that since the people at GAMI seem honest and I can't imagine they would see a product that wont work on these engines.  So the guestion is could it be that some of these engines won't go LOP or it likely a GAMI tuning issue?

[TLSDriver]

Ken,

If LOP wasn' in the cards how did you end up leaning your Bravo?

 

David

[KLRDMD]

Quote: TLSDriver

If LOP wasn' in the cards how did you end up leaning your Bravo?

[TLSDriver]

Just when I thought I coudn't get more confused I just came across this little gem:

Mixture Setting 50 Degrees Rich of Peak TIT (Turbine Inlet Temperature)

The articles says to lean until TIT peaks - not egt.  Then reduce it by 50 degrees.

Anyone doing this?

[KLRDMD]

Quote: TLSDriver

Just when I thought I coudn't get more confused I just came across this little gem:

Mixture Setting 50 Degrees Rich of Peak TIT (Turbine Inlet Temperature)

The articles says to lean until TIT peaks - not egt.  Then reduce it by 50 degrees.

Anyone doing this

?

[TLSDriver]

At the risk of sounding like a complete idiot was this your procdure: Lean until the TIT didn't rise anymore.  That was peak.  And then go richer until you were 150 degrees cooler than that.

Do I have that correct?

David

[KLRDMD]

Quote: TLSDriver

At the risk of sounding like a complete idiot was this your procdure: Lean until the TIT didn't rise anymore.  That was peak.  And then go richer until you were 150 degrees cooler than that.

[Cruiser]

you should be able to lean your engine smoothly if equipped with GAMI injectors. The JPI will record the data. Using TIT is important for you turbo guys, but it is more of a lean it quickly so you don't exceed max TIT. Leaning methods are techniques for getting the red knob where you want it. It has little to do with whether or not the engine will RUN lean of peak. You should do a GAMI check to see how the fuel flow is balance on your engine.

GAMI injectors are individually tuned to each specific cylinder and as such cannot be randomly moved around. They MUST be put back into the same cylinder they were built for. Typically the GAMIs should get your fuel flow to less than .5 gph difference (richest to leanest) if you cannot achieve this call GAMI, they may have info on your engine.

[TLSDriver]

Quote: Cruiser

you should be able to lean your engine smoothly if equipped with GAMI injectors. The JPI will record the data. Using TIT is important for you turbo guys, but it is more of a lean it quickly so you don't exceed max TIT. Leaning methods are techniques for getting the red knob where you want it. It has little to do with whether or not the engine will RUN lean of peak. You should do a GAMI check to see how the fuel flow is balance on your engine.

GAMI injectors are individually tuned to each specific cylinder and as such cannot be randomly moved around. They MUST be put back into the same cylinder they were built for. Typically the GAMIs should get your fuel flow to less than .5 gph difference (richest to leanest) if you cannot achieve this call GAMI, they may have info on your engine.

[danb35]

See http://www.gami.com/gamijectors/leantest.php.

[Cruiser]

Quote: TLSDriver

[TLSDriver]

Quote: Cruiser

[TLSDriver]

I just saw the linke about sending downloaded data from the JPI.  I dont have teh cables they refrence.  I will look at the unit today and see if I have a usb port on the face of the box.

If that is the case is appears that I can use a USB memory stick to grab the data.

 

David

[carqwik]

I run my engine at 30"/2400...lean to peak TIT then enrich about 90 degrees.  Do not exceed 1650 degrees for more than a minute while looking for peak.  Enrich the mixture so it is well below 1650 in cruise, 1600 or less is preferable.  Climb out should be in cruise climb at 120 kts or better at 34/2400 at 1550 degrees TIT or less as required for engine cooling.  On descent, lean out mixture as you reduce MP to keep things toasty.  Use cowl flaps as needed to keep CHTs below 400.

That's the way I run my bird...

[TLSDriver]

Quote: carqwik

I run my engine at 30"/2400...lean to peak TIT then enrich about 90 degrees.  Do not exceed 1650 degrees for more than a minute while looking for peak.  Enrich the mixture so it is well below 1650 in cruise, 1600 or less is preferable.  Climb out should be in cruise climb at 120 kts or better at 34/2400 at 1550 degrees TIT or less as required for engine cooling.  On descent, lean out mixture as you reduce MP to keep things toasty.  Use cowl flaps as needed to keep CHTs below 400.

That's the way I run my bird...

[carqwik]

FF is 18.5 gph at normal cruise.  Speed is 180 kts at 10k.  Bravo does best in the high teens for speed.

Btw, cruise climb TIT should be 1450, not 1550 as I wrote.

[TLSDriver]

I am going to fly it tonight and see how close I come to those numbers.

 

[thinwing]

David in order to download data from your jpi 700 you will need a m type to usp connector sold by kpi.There is no usp connector on the unit itself but mounted close to the unit you should be able to find a m stvle port and could be marked data.You will also need to download program from jpi and read your jpi 700 manual that explains performing a data dump.Ps....The tls/bravos should not be run above 1650 TIT and I know of some bravo drivers leaning to 1550 and accepting the resultant 20/21 gal cruise fuel burn ...changing out a bravo jug is expensive!!!..sinc kp couch

[TLSDriver]

Quote: thinwing

David in order to download data from your jpi 700 you will need a m type to usp connector sold by kpi.There is no usp connector on the unit itself but mounted close to the unit you should be able to find a m stvle port and could be marked data.You will also need to download program from jpi and read your jpi 700 manual that explains performing a data dump.Ps....The tls/bravos should not be run above 1650 TIT and I know of some bravo drivers leaning to 1550 and accepting the resultant 20/21 gal cruise fuel burn ...changing out a bravo jug is expensive!!!..sinc kp couch

[DonMuncy]

Actually, at least on 6 cylinder Continentals, GAMI sends three pairs of jets; one set for the front 2 cylinders, one for the middle and one for the rear ones. It that does not bring the spread close enough, they will swap you some individually tweaked ones to get it closer. I'm not sure I understand why most any engine can not be tweaked to run LOP.

Don

[TLSDriver]

I seem to have read that if you are going to try and run LOP you should use max power of 65%.  I can't find a chart in the POH that gives these numbers.

I am guessing 28" is close.  Do you agree?

 

David

[Earl]

I have an 86 252 with OEM injectors and have never been able to run LOP.  I did a GAMI test and sent it over and they said "GAMI injectors would probably help" since my spread was not too bad.  Still haven't done it.  As for how I run my engine, since I put in my EDM-730 when I am at anything above 65% power I run 100dF ROP which keeps my CHTs from 290 to 360dF and around 1400 dF.  At 65% power or less I lean it out until it doesn't run smooth and then enrich until it does as you can run as lean as you want under that power setting.  Usually burns around 13.5 gph at 65%.

[KLRDMD]

Quote: TLSDriver

I seem to have read that if you are going to try and run LOP you should use max power of 65%.  I can't find a chart in the POH that gives these numbers. I am guessing 28" is close.  Do you agree?

[danb35]

Quote: TLSDriver

I seem to have read that if you are going to try and run LOP you should use max power of 65%.