We get numerous letters and emails from our customers telling us how pleased they are with their new set of balanced fuel injectors. Below you will find a selection of such correspondence mixed with praise found on mailing lists.
- ROP vs LOP engine operation and related engine durability.
Steve, My son and I have operated a V35TC since 1981. Early on we put in a factory reman and after 400 hours started replacing cylinders almost every annual. In 1995 put in Gamijector fuel injectors and a JPI and started running LOP. Since then we have not pulled a cylinder and have run 2 engines 200hr beyond TBO.
I mention this on the possibility you are not using LOP operations, in which case you might consider going "to the green side" or "LOP-sided". As far as I'm concerned, LOP ops save this airplane from being a maintenance hog.
- Should have installed these a long time ago, surprised what a difference it makes.
Broke down and installed the Gamijector fuel injectors and what a difference. I fly behind a TN520 and I am a couple years (I hope) from a motor rebuild. I thought I would wait and just run the stock injectors until it was new motor time but decided to get the Gamis now and just move them to the new motor when it is time. I sent my JPI files to John-Paul and my current spread was .9gph, 3 days later my new injectors show up, we installed that day and went up for a quick flight, noticably smoother and a new spread of .5gph. Talked to John-Paul again and he is sending out 3 more injectors to fine tune her to what we hope will get us to a .3gph spread or better.
This weekend I flew for 2 hrs and what a difference in LOP smoothness going from the .9 to .5gph spread. If we get her to a .3 spread and she gets that much smoother again I wont even know she in running. Well the moral of this story is if you are sitting on the fence about installing the GAMI fuel injectors just get on the phone to John-Paul and get them ordered. Really does make a huge difference.
(Older filghtcraft TN system, Original owner of plane thought is was smooth/close enough with stock injectors. I purchased and have flown her for a couple years this way thinking it was fairly smooth also. Could feel some rumble when LOP but not uncomfortable, Should have installed these a long time ago, surprised what a difference it makes.)
- If you are thinking about GAMI injectors move forward and do it!!
To the Fine Folks at GAMI
I would like to share my experience with the recent installation of GAMI injector nozzles in my 2008 Mooney Acclaim with a TSIO-550-G twin turbo-charged engine. This engine from the factory has a TCM tuned injection system with position tuned injector nozzles. After doing a GAMI flight test to measure the actual fuel flow spread I learned that my tuned engine was actually 1.0gph spread from the first cylinder to peak to the last cylinder peak. After installing the GAMI precision matched injector nozzles my GAMI spread is now 0.3gph.
My engine now runs smoother, idles better and at a lower RPM and runs totally smooth at 85F LOP. What a fantastic improvement on what was a factory tuned engine. If you are thinking about GAMI injectors move forward and do it!! It is only about a 2 hour installation for your local mechanic and will transform your aircraft into a more economical and cleaner burning transportation platform. The savings will payback very quickly.
- $6,786 in savings
9500' @ 55% power, WOT, Oil Temp 168°F, 33 degrees between cylinders, 76 DIF/EGT, @11.2gph.
12.4 MPG, ground speed 139 knots with tail wind.
A/S 125kt with four people aboard , weight 3309lbs.
240 hours on the engine since 3/1/2012.
All things considered, saving on Volume of fuel saved, Lower price of fuel because I am buying fuel in town at $5.30 per gallon verses $9.10 per gallon in villages, 50 hour oil changes and misc stuff is $6,786.00 since March 1st, 2012.
This is a 1969 Cessna 206, with a Continental IO-520-F, used by a plumbing and heating company to perform repairs and haul parts to remote villages in Alaska.
Click here for a breakdown of how Jim calculated his figures.
- A happy camper for sure
Wow I must say I was very impressed with my trip to GAMI for sure. After flying up this morning with 2 and 6 running hot the whole way almost 50-60 degrees hotter than the other CHT's even at cruise. After landing John-Paul met us at the plane and they started working on it as we walked into the office. John-Paul gave us a tour and I was very impressed with the operation and Tornado Alley Turbo shop. If that was not enough they then loaned us a car to go to town to eat.
After a great lunch we returned and waited for the repairs. John-Paul was great about keeping us informed about progress and about 4pm we where ready to roll. After a preflight we were off, on takeoff I could not believe my eyes #6 was running as cool if not cooler than the rest and 4 was also within 10-15 of the others. At cruise the same spread was found there also, you could not get the smile off my face for the next 297nm. I cannot thank GAMI And John-Paul enough for the great work. If you are ever around ADH do yourself a favor and stop in for a tour or some great work. They made me a happy camper for sure.
- Congratulations on such a fine operation
I arrived in Ada late last night to pick up my plane and test flew it this morning.M
I have been around a bunch of maintenance shops in the past forty years, but have never encountered anything that approaches your operation in terms of competence, thoroughness, and quality. Youíve got to be proud of your guys. As expected, the engine runs great. But why shouldnít it; itís your design. What really blew me away, though, was the thoroughness of the inspection; Iím sure your guys didnít miss anything. And the documentation: the inspection report is a quarter-inch thick and tops anything I have ever seen.
I think every turbo owner should come to Ada once per year for an inspection. You can be sure that Iíll be back next year.
Congratulations on such a fine operation.
- G'day folks
Please find attached the flight test data for our newly installed GAMI Injectors on our 1983 Beech Baron 58.
Iíd also just like to state how highly impressed I am with the injectors. I was absolutely blown away how smooth the engines are now! I recently completed 2 long flights (7+ hours) of identical routing, one prior to the GAMIís and one after using the lean of peak method. Comparing the two flights saw an incredible fuel saving. Although running lean of peak extended the total flight time by 0.2 hours, we experienced a total fuel saving of 93 litres! Given the price of fuel in Australia, that represents a saving of approximately $180.00. Needless to say we were very happy about this!
We are in the process of purchasing more aircraft and will certainly be adding GAMI injectors to our growing fleet.
- GAMIjectors in the tropics
I'm in Belize doing my annual conservation flying. Been at it for a week in temps that sure aren't Oklahoma in summer but are plenty hot. In the midst of your day-to-day challenges, this is, pure and simply, a thank you for GAMIjectors. GAMIs with LOP ops here in the tropics are just what a nonprofit concerned with fuel prices and engine wear ordered. Burning under 10 gph in a Cessna 206 while hanging photographers out the door as I fly over a large area of jungle or stretch of reef, with all CHTs below 370 and cowl flaps closed is frankly, impressive.
When I was doing this before GAMIs and an understanding of LOP ops the mixture was firmly against the firewall, cowl flaps were open, adding drag and cost and head temps were up where cylinder replacement was a regular fact of life. I don't often think of a 206 and the word efficient in the same sentence but I've spent the last week again being impressed with GAMIs and what a contribution you have made to public benefit flying by taking a nice chunk out of operating costs.
When people are complaining about this or that, keep in mind that there are those who appreciate what you've done,
- Non-stop Vegas to Houston @ 301kts
It was great to see you folks yesterday. Drue and I are working on a summary at this time and will pass it on to you. Attached is the photo I told you about in my B36TC. My fastest ground speed so far at 23,000 feet, 301 knots. Non-stop Vegas to Houston. Landed at 2am. Was burning 13.6 gallons per hour lean of peak. 25mpg. 31"mp and 2400rpm
click thumbnail for larger image.
- GAMI injectors vs TCM "position tuned" injectors
In a post last year I detailed my (horrible) experience with the TCM injectors in a 2008 Factory Rerman IO-550. If you want the gory details you can search for it.
The short version is the TCM balanced injectors were badly out of balance, TCM acknowledged the problem, but would / could not resolve the problem.
100% happy with the GAMI's that replaced them...
- Beats the hell out of 50 ROP and 25 square
So after reading everything I could on engine operation, I went up tonight to do some real world tests in order to better formulate the SOP for our partnership. The goal of the SOP is to come up with a balance between speed and efficiency in an easy to follow procedure.
Here are some of the results:
GAMI lean tests show a .2 - .3 GPH spread. This is a HUGE improvement over the "balanced" TCM injectors.
- 10 GPH in a turbo-Arrow III
I fly a turbo-Arrow and really like it. For Saturday afternoon loafing around the area, the turbo won't make any difference. But climb into the flight levels and catch a tailwind...man, can that put a grin on your face.
Mine is a turbo-Arrow III, 1978. Useful load is around 1090 pounds (with a lot of gadgets on the panel), or about 660 with full fuel (72 gal useful). TAS of 150 knots is easy, and up in the high teens or lower flight levels I get about 175 knots TAS. [Note: I highly recommend the Meryln wastegate. Adds about 5,500 feet to your critical altitude, increases high-altitude TAS some, and extends the life of your turbo and engine down low.]
Range--600nm is only about 4 hours, so that's not a problem, even at 75% power. If you REALLY want to extend the range, get GAMIjectors. That drops off about 1.5 to 2 gph from the fuel flow, and gives you another hour in the tanks. I typically fly now with about 10 gph and 70% to 75% power. That shows an easy 150 TAS or better (even down at the 10k altitude range), for a SEVEN hour no-reserve endurance, and over a 1000 mile range."
- All the way from Zambia
After 14 months of restoration, she is getting close. The first ground runs were with the original injectors, then we installed the GAMI's. I did not need the EDM 700 to tell me that I had spent my money wisely. (It told me anyway).
The motor is notably smoother and more responsive with mixture totally controllable - now Busch and Deacon are making sense - I cant wait to fly her now.
Thanks for a great (revolutionary) product.
- Bob Zarracina's experiences running lean of peak
I first heard of GAMI injectors during email conversations with John Deacon via AvWeb. The initial conversations centered around engine operation since I was doing a top overhaul on the TSIO-520-UB, notorious for losing compression midway through engine life (TBO). John was most helpful and I formally thank him for his assistance. I owe him the libation of his choice in quantity. I wanted advice on how to manage the engine better to promote longevity. Having been involved in engineering (ME) in my younger days, I believed that this engine can make TBO, cylinders in all, with the right information. I had participated as an amateur drag racer for several years and never lost a motor (or compression) so why the problem here? John's suggestions were Millenium cylinders, GAMI injectors and JPI EDM-700 graphic engine monitor. I followed his suggestions 100%.
My mechanic and I worked with George Braly concerning modifications to the baffling system, break-in, and ultimately running LOP. To say I was a bit AR (anal retentive) is an understatement but George endured. To provide perspective, after the initial run-up, I had the aircraft towed to the approach end of 27 (MLI), called the tower and requested an immediate departure prior to engine start. I know that the first few minutes of break-in can determine the eventual and long-term outcome of good cylinder ring seating, and I wasn't about to blow it all with 15 minutes of taxi time. George said to run the engine at 33-35"MP, full rich, to break-in the jugs. This is where the profound perspiration begins, since previously I had to do everything I could to keep cylinder head temps below redline, 33-35"MP was not one of the techniques that worked. After a full power departure and the cockpit filling with water (sweat) I chickened out and pulled the throttle back to 31" MP, my eyes glued to the CHT gauge as I diverted the flood from my forehead. Great, here I am breaking in a new set of cylinders with a technique that has not previously worked, wondering what George's response was gonna be when I call him and tell him that I just set a new world record for the shortest flight and life of brand new cylinders. Since George is a barrister (attorney) by trade, financial recovery was not even a hope.
Shortly into the flight an amazing thing happened. The CHT rose to 175-180 and then started dropping (what? not going to redline?), settling in at about 150-160 (must be something wrong with the gauge). With a sweat socked right hand, towel in trail, yep, I did the unconscionable, pushed the throttle in to 33, then 34 and then 35"MP (I've have now certifiably lost my mind). The CHT didn't budge. How can this be? The remainder of the flight was as stable as the CHT that day, only that night's shower was one of most soothing that I can recall. Well I again followed George's suggestions for the next 4.5 flight hours to insure ring seat, noting the CHT sitting between 150 and 175 depending on OAT, flight attitude and altitude. I've never seen CHTs this low.
Then came the fateful day. Here we go again, I've survived the first round only to set myself up for the LOP test (I mentally called it Loss Of Perspective) where I'm gonna fill out this chart as I lean the engine past peak to a point where George says "just keep leaning it out until you don't feel comfortable any more". Just peachy. I hated to tell him that I "didn't feel comfortable" even before I started the engine. I could just imagine George and his staff laughing while I'm filling out this darn chart as pistons, connecting rods and sundry parts are leaving my engine and aircraft in flight (I've have now confirmed and authenticated my lost mind certificate). I looked over the warranty on the Milleniums to determine coverage, since I certainly would be calling them shortly. Prior to departure and with previous flights experience, I took off with two of the largest beach towels I could find too.... well you know. Once stabilized I began the test (I knew I should have worn swim trunks). I started at 18 GPH decreasing in .25 GPH increments until 15.0 GPH was reached, dutifully writing down these series of EGT and CHT numbers that would make my engineering instructor proud (neither seriously approaching redline). I can't really say that the engine was running all that rough at the last setting but I can say that my perspiration was at an all time high and nerves at an all time low. Hmmmm I'm still flying, engine has never run this cool, lets see, no parts exiting or oil coming out of the engine, egad what's happnen here? With only the bravado that a bull fighter could know, I did the test again and on subsequent flights conducted three more spanning the GPH spectrum from 18.00 to 13.25. yep 13.25 wow! Oh by the way, that nights shower was taken with aplomb.
Well the answer should be obvious, I'm a convert, a believer. I'm in the final phases with GAMI to tweak a few injectors but the results are nothing short of phenomenal. 1) the engine has never run cooler even on hot days (95 F surface temp) usual cruise settings are 31"MP and 2400 RPM but in discussions with George and company will have no reservation about increasing either, 2) oil consumption is non existent and the color remains in its new state for most of the 50 hours its used and 3) the BIGGIE, prior to GAMI's I was burning 19.5 GPH in cruise, now I burn 15.5 GPH with no loss in airspeed, a 4.0 GPH spread. Let's see 4 GPH times $2.61 per gallon times flight time per year - wholly molly that's some serious $$$'s.
Epilogue: I often share my newly acquired knowledge with interested pilots but must admit, most think I'm nuts. One particular aviator made my day however, when after explaining my adventure he told me a story, flying in WWII, when Charles Lindbergh discussed with his group, LOP operation of P-38s and other aircraft to increase range and/or duration. My thanks and gratitude to George, Bill and the staff at GAMI and to John Deacon who all contributed, in my estimation tirelessly, to my flying education. I look forward to meeting you all personally - first round is on me.
- A class act
I purchased a set of GAMI's for my A36. On the first GAMI lean test, the company sent me new injectors for #5 & #6 without me asking for them. I replaced these injectors, ran a second GAMI lean test and sent this one in too. Got an immediate e-mail back that the company was going to send me a new #3. WOW! I am impressed! This should place all cylinders within about 0.2 gph of each other at peak.
THANK YOU TO GEORGE AND EVERYONE AT GAMI. YOU RUN A CLASS ACT INDEED!
- Controlling CHTs
LOP operation with GAMI's are very effective in controlling CHT's on my B36TC. I do not do LOP climbs. But I monitor my CHT's on a GEM610 during climb and try to keep CHT's below 400. On hot days when the CHT creeps up above 390 on a climb first thing I do is turn on the low boost pump. That adds about 1.5GPH to the FF and drops the CHT's about 10 degrees.
If I am climbing to the high teen altitudes I may level off at 12K-13K for a few minutes and run at LOP cruise. This drops the CHT's by 30 degrees or more. Once the CHT's cool down I can resume my climb and get to altitude before the CHT's creep up too high.
Without GAMI's at high cruise power settings my hottest cylinder (6) can run 390-410. Running LOP with GAMI's cyl 6 runs nicely around 360.
The B36TC has the same wing as the Baron and carrys 104 gallons of useable fuel rather than the standard 76 gallons most late model A36 and A36TC's carry. Beech put the Baron wing on the B36TC to be able to increase the fuel capacity and gross weight from 3650 to 3850.
With GAMI's on my B36TC I can cruise at 175Kts-180Kts on 14.5GPH for almost 7 hours.
- Cooler, cleaner, cheaper
Mind if I ask a very basic question about this never ending subject of ROP-LOP? How much fuel does one expect to save with all of this?
Having just done my taxes, I know the numbers. I spent about $9,450 on avgas last year.
I save 3.5 gallons an hour. ROP is 18 gph, and LOP is 14.5gph. (The IO-520 is turbonormalized -- normally aspirated engines would burn less, but the savings are about the same.) In rough numbers, at current prices (avg. $2.40 a gal) that's $8.40 an hour I'm saving. I flew about 280 hours last year. That's $2,352 I didn't spend to cool my engine with expensive gas.
"Fuel is cheaper than cylinders" I hear people say.
That statement is worth closer examination.
Let's assume 250 hours per year. (250 hours X $8.40 savings per hour = $2,100_ 1700 (TBO) / 250 = 6.8 years.
6.8 years at $2,100 a year = $14,280. That sure helps pay the overhaul.
With 120 gallons on board, I plan to land with no less than 20 gallons. I average 15 gph from startup to shut down, so I have 6.5 hours of useable fuel -- at 190 kts. Running LOP gives me two hours of additional range -- about what John Small calculated for his plane.
It's cooler, it's cleaner, it's cheaper, it gives added range (which means safety).
If a pilot/owner flies 150 hours a year, the savings would be about $1,200. After five years you have bought a nice piece of avionics by running the engine in a manner that, I believe, is better for the engine.
- From a New Customer survey
Comments: Fuel manifolds overhauled by Dave Dewell, flowed, engines run together perfect! When leaned, fuel flow needles the same, EGT the same, and all of this without readjusting the fuel injectors.
M Voracek, TX
- GAMIjectors in Africa
So.... There I was, in Namibia. It's a LONG way from ADA. I fly from Shreveport to Atlanta, then to Dulles, then the 18-hour flight to Johanesburg, then to Windhoek (capital of Namibia), where we are to take a Cessna 210 to the gravel strip at the hunting camp at Eden Wildlife Trust.
What do I see on the front of the Cessna? A decal for GAMIjectors. The pilot says they use GAMIjectors in all the planes, and save 5 to 6 litres per hour. They run at peak in cruise. Winhoek is 5,500 feet elevation, and we cruised at 8,500 to 10,500, 2400 RPM, WOT.
So, I had to get this picture on the gravel strip where the giraffes graze.
Tom Gresham - Wings to Adventure.
- GAMIs on a Debonair?
I am not an advertisement for GAMI's but this is what they did for me. I have an IO-550 on a Debonair. It ran smoothly lean of peak and was not rough before the GAMIs. What the engine didn't do, was peak the cylinders at the same time. My first cylinders peaked at 17.5 gph indicated, the next peaked at 17.0 gph and the third set peaked at around 16.5 or 16.0 depending on which test you read. My spread of cylinders reaching peak was from 1 to 1.5 gph. I used to run at about 17 gph indicated, LOP of the first cylinders peaking. That meant that while my 1 & 2 cylinders peaked, 3 & 4 were at peak and the others were still coming up.
I questioned what they would do for me. If they brought the fuel flow down .5 gph they might pay for themselves. I was really hesitant about spending the money but I didn't like the spread on the fuel flow. I bought the GAMIs and had them put in. All the cylinders now peak at the same fuel flow. The company was hoping to get them within .5 gph as I recall. They are right on and that made me happy. I would imagine there is some difference in fuel flow between peaking, but I can't detect it. I now run LOP at 16 gph indicated. When the first cylinder peaks egt and starts down - all the cylinders are going down. I have done the test several times. Same result!
What that means to me is that all cylinders are pulling at peak power at the same time or LOP at the same time. The temps are cooler EGTs run 1325-1450 while the CHT runs at 325-350. (summer weather with ground OAT at 90+) I don't detect the engine running smoother, but I figure that if they are all pulling together at the same power levels (I'm no engineer either) that must be good. IF that isn't good, I am saving about 1 gph which will pay for the injectors in about 400 hours. My fuel flows are indicated and the actual fuel usage is about 2 gph below the indicated which runs off a pressure gauge.
The education part of this is doing the test that is described in the GAMI web site and finding out what your engine is doing. If your temps are too high and you might benefit running LOP, then that is another advantage. I figure that low usage and high heat are what kills the engines. I am trying to keep both of those gremlins out of the engine and at some point will be able to advise if I make TBO. I am doing about 300 hours per year now.
- Great fuel efficiency
By the way, when I airtested the A36 in South Africa, I noted a fuel flow of 13.2 gph at 65%, very close to the book figure. We replaced the injectors and ferried the aircraft back (10% overweight), a 6500 nm trip over five days. Average fuel burn for the ferry flight was 10.8 gph!
- Kind Words
I am the owner of a Beechcraft 35-C33 Debonair, modified to take a IO520BB engine. I put a remanufactured engine in in the spring of 2001, and it now has a little over 1300 hours on it. It was installed with GAMIís and a JPI 700 with gasket CHT sensors. Having read all of John Deakinís articles in AvWeb, I have flown it in accordance with Johnís from-time-to-time LOP procedures from the beginning. (The only big change I remember is ROP climbs.) The highest any CHT ever got was 425dF, when I got a new clearance in bad weather very shortly after takeoff. That was in the old LOP climb days. The plane does not have cowl flaps.
Anyway, the experience of LOP flying has been delightful. I have had to replace two cylinders because of bad exhaust valves, which I have no doubt is a TCM problem. Otherwise, the engine has been next to perfect. I am very comfortable with the cool CHTís and the excellent fuel economy. An associated big advantage is the range. I recently completed non-stop trips from St. Louis to KOXC in Connecticut (with the DENNA2 arrival, more than 900 NM) and one to Naples, FL, about the same distance. At a density altitude of about 13,000 feet, with the rpm pulled back to 2300 or 2350 and 10dF LOP, I use a little over 10 gph. By using 41 gallons from the left tank on both flights, I landed in each case with almost 15+ gallons, not counting the unusable fuel (and I donít count it) in the right tank. Airspeed in such conditions is about 152 knots.
I should also mention the service GAMI gave me. I sent you the results of a GAMI lean test early in the engineís career, and you replaced two injectors.
Anyway, you at GAMI have done a great deal for the piston side of general aviation, and I am very grateful.
- My friend has GAMIs, why can't I?
Yesterday I had the fine good fortune to fly here in Colorado with my good friend Tommy Flocks in his Bonanza A-36, lovingly turbocharged and GAMIjected by yourself. What a treat!! I normally fly a 1979 carbuerated Cessna TR182, which is nice but hardly smooth. I couldn't believe how smooth and quiet the Bonanza engine was and how little fuel he burned when running lean of peak. Finally, when we approached the airport and he began a 1000 fpm descent by pulling power back drastically and then leaning to maintain peak temps, and showed me how the cylinder temps were so nicely gradually cooling down, I was amazed. You've done the aviation world a great service by dispelling a lot of OWT's and providing some great systems.
Too bad nothing can be done to improve the fuel delivery on my O-540-L3C5D.
- My grateful thanks
Thank you all at GAMI for a excellent product and for the superb technical support that you offer.
I'll never own another piston engine aircraft without GAMIjectors and a JPI monitor. If they are not installed, I'll add both immediately after purchase.
In my B55 Baron and at George Braly's suggestion, I installed a JPI monitor about a month before I installed the GAMIjectors. He thought it took some time to get used to the JPI display and the procedures for downloading and analyzing the collected JPI data. I have come to agree. On the third flight after installing the JPI, I experienced a partial engine failure on departure (see here) and was so pleased to be able to use the JPI data (with lots of help from GAMI and others) to prove that the partially blocked fuel line - resulting in a massive "overlean" condition - had not damaged the engine in any way.
Subsequently, I installed the GAMIjectors and ran a series of tests to get the engine/injector combination balanced. In that process, we had one cylinder with very high CHTs (occasionally 400+F) and Bill Wallace at GAMI began to suspect that I had an engine induction leak. He was right... after repairing that small checkvalve, the left side engine, which was all out of whack because I didn't have a tiny ball in my intake drain checkvalve is now running so, so smoothly...It's close to perfect now.
George, thanks for the suggestion to put the JPI in first.. You were right.
As an example, on the way to the shop recently, the right engine #6 EGT was way too hot, so I asked them to clean out that partially-clogged injector.. There is NO WAY I'd have known or heard that cylinder about to burn up without the JPI, as the single-probe factory EGT data is collected well downstream in the combined stack, and the factory CHT probe is on Cylinder No 5.
So, being perfectly comfortable with the condition of these engines, I took off on a long flight to far northern Labrador... (see here) which I would never have done if I thought the right engine partial failure on takeoff had hurt the engine!
Bill Wallace, who analyzes the JPI data we send to GAMI, is both critical to the success of the GAMI product and superb at doing so. His high standards of excellence give me confidence in my engines as they purr on each side of me.... whether in the rugged northern mountains or down low over the pack ice.
My grateful thanks,
- Putting Lean Of Peak to the test
Those of you who attended the GAMI Seminar on lean of peak operations in October at Homecoming are aware of the convincing argument put forth by George Braly during the event.
Given that my GB Engined, K model is equipped with turboGAMIjectors, I decided to put LOP operations to the test during a recent round trip from San Antonio, Texas to Atlanta, Georgia. Here are my non-scientific findings.
Eastbound, I filed for fifteen thousand feet. Once at altitude I brought the prop back to 2450 and pushed the MP to 32" (temp was standard +10). I gradually leaned back to 100 degrees lean of peak and then tweaked the MP to get book readings of 70% power. CAS settled in at about 200 MPH (cowl flaps trailing). Oil and Cyl Temps remained middle range. Most noteworthy was the incredibly low fuel burn. Despite being rerouted by Houston Center all over south central Texas and again by Memphis Center around active MOA's, I arrived in Atlanta with 18 gallons of my original 72 gallons still in the tanks. 10 GPH was the average burn rate.
Impressed as I was, we flyers know the real test comes when flying west into the prevailing winds. This time I chose eight thousand feet (my turbo bird does not like flying lower than that). Again book settings for 70% power (temp was standard). This time I was able to close the cowl flaps and yet maintain a centered oil temp needle. The cylinder head temp seemed to run cold (still in the green though). CAS settled in at 185 MPH and most importantly, fuel burn remained around 10 GPH. Four hours thirty minutes later I'm back in SAT with a mere forty two gallons missing from the tanks. I probably could have flown on to El Paso if I'd had the personal bladder to do it.
In summary, the engine does not seem to mind LOP operations. The 70% versus 75% operations seemed to only marginally effect airspeed. Most notable was the lack of need to make a fuel stop. That "non-event" makes up for any slight speed sacrifice resulting from conservative power settings.
While this one trip does not totally convince me LOP operations are the best way to balance the fuel/engine expense equation. I have not as yet seen anything that convinces me I should revert to my old Rich of Peak ways.
Time will tell. Comments Please.
- Remarkable, really remarkable
I couldn't wait to share the results of a TCM inspector's (Dave Blanchard-TCM's Eastern Regional Rep) look at my exposed piston and cylinder walls after 300 of the 400 hrs I have on my TSIO-520. Number 1 and 3 cylinders had been removed as part of the TCM crankshaft inspection AD.
He said,"Hey, whatever you are doing, don't change a thing!" The cylinder walls "looked brand new," he said. He even pointed out traces of the hatch lines remaining from the original break-in days. There was no evidence of scoring, pitting, or heat damage. I mentioned that I had been running 100F LOP and using GAMIjectors. He took another look at both exposed cylinder walls and pistons and said,"Remarkable, really remarkable!
If anybody still doubts the beneficial effects of running LOP with GAMI's, have them contact me.
- Saving 17% on a twin-Beech fuel bill
I finally installed EGT guages in the Twin Beech and WOW, have I learned some things. We were right in some of our assumptions--mistaken in others! First, the old standard way of leaning to a slight power loss and enrichening til it goes away as I have been taught by several unnamed radial experts leaves one with a 40-42 GPH fuel burn in the 985--just right by all OWT accounts. It also leaves the EGT AT 25 ROP and the CHTs between 400 and 425dF. This was recommended by these experts as THE place to run these engines and if run leaner than a 42 gph would blow cylinders, being too lean and too hot.
This weekend on the way back from Duluth, MN, I played around a bit. I found that by leaning to 50dF LOP, the CHTs would be around 375--25-30 cooler. Another side benefit was that there was NO gunk on the nacelles after flying 5+20; when running ROP, there would be a fair amount of exhaust and oilly goo on the nacelles after just 2 hours. Also, the exhaust stacks were devoid of ANYthing when running LOP... a very slight, very light tan dust was all that was there after 5+20. Before, there would be an oilly black slime in the stacks. Another thing I learned is that the mixture change to go from 25 ROP to 50 LOP is very small with these carbs. Much too small to do anything worthwhile by ear or feel. Not at all like leaning the injected engines, the change must be very slow and very small to see the delayed EGT change--unlike the IO-520 which EGT changes almost instantly with mixture changes. The difference is just as great as in the injected engines though (kinda like on your lawn mower, too!)
The engine would run 100dF LOP but any leaner and it would QUIT--just quit. Never got rough like an IO-520. It'd just quit at anything leaner than 100dF LOP. I finally settled on 75dF LOP for CHT cooling and fuel economy. At 9000 feet I was running 1950 rpms, 27" MP and 75 LOP getting a TAS of 165 knots. I used to run it like I'd been taught at 1800/25 with the same TAS but with CHTs above 400. (you know I've changed 4 cylinders, huh? I wonder why?)
The supposed "sweet spot" for the Twin Beech is 10,500. 1950/26 at 25 ROP was getting most people a TAS of 160. I think it better to be at 8-9000, higher MP, 50dF LOP with CHTs lower by at least 25dF and 165 ktas! Besides, the 50dF LOP setting results in a 35 gph fuel burn rather than 42 gph! Hmmmm, would you like saving 17% on a Twin Beech fuel bill?
How's that for a data point! Nothing like a little instrumentation to find out what the hell is really going on, huh?
You're grinnin', aren'tcha ?
- Saving gas!
I got Gamis in my 470 and love them. I run LOP; couldn't before. I now think my airplane uses less fuel on a trip than some SUVs!
- Sharing experience
This information was taken from an e-mail conversation between Tom Turner, noted aviation author, and Allen Wolpert, a happy GAMI customer out of White Plains, NY. We thought you might find this interesting.
I understand you are interested in information on cyl temps and LOP operation on the B36TC. I have had GAMI injectors installed for about a year and 150 hours on my 1984 B36TC. I also have a GEM610 installed, so I have extensive EGT and CHT data recorded and saved. I also have a Shadin digital fuel flow display. Unfortunately the GEM610 does not log fuel flow.
Cyl6 is consistently my hotteset CHT, followed by Cyl4. Cyl6 CHT needs to be monitored carefully during climb. Cyl6 CHT can easily exceed 425F. I try and keep Cyl6 below 400 on the climb, but sometimes it sneaks up on me to 410. I have my FF on takeoff around 34-35GPH, at redline or a bit above. If Cyl6 CHT is creeping up on climb I've found turning on low boost gives me another 1.5-2GPH during climb and can bring Cyl6 down by 10-20F degrees.
At cruise 50ROP on the TIT is about 16.5-17GPH. Running ROP Cyl6 CHT may drop to 390 if that much. Running 50LOP Cyl6 drops down to 350-360F. I run 31/2400 at 50LOP at 14.5GPH which gives me performance equal to the POH at 28/2300.
Data on a recent flight-
20 minute climb SL-9500, hot day in the east 90+F on the ground, running low boost during climb for additional cooling.
CHT at TOC-338 338 332 351 365 397 Peak TIT 1646 All EGT's peaked at 1646 TIT!! 1544 1518 1518 1492 1497 1492 Cruise at 50LOP TIT 1595FF~14.5 GPH, CHT at Cruise-325 325 319 338 312 358 EGT at Cruise-1501 1475 1492 1458 1450 1441
Running LOP let's me run Cyl6 at 40F-50F less then ROP. I can easily cool Cyl6 by leveling off running it LOP for a few minutes then continuing my climb. Running ROP does almost nothing to cool Cyl6 after a climb and it takes a long time to drop 10F or 20F.
I used to have a GEM603. I wish I had installed a GEM610 with digital CHT display sooner. The digital display let me identify and repair some baffling problems I had. I now have the ability to directly manage the temp on Cyl6. I normally keep the Cyl6 CHT displayed on the GEM during a climb as it is my limiting factor for climb speed. Changing my climb rate/IAS has a major impact on Cyl6 temp. Climbing at about 140kts IAS/500 FPM I can keep Cyl6 below 400F. Climbing at 110-120kts IAS/700-1000FPM rapidly gets Cyl6 to 410F+.
Maybe George's improved baffling will help someday. In the meantime I manage the fuel flow and climb speed to keep Cyl6 CHT within limits during climbs. LOP operation keeps Cyl6 cool during cruise and descents.
I hope this is the data you are looking for. Let me know if you'd like more specifics either here or via email. Happy to share with you my experiences, and maybe I'll even learn something.
- Southern Compliment
Just flew for the first 1st time w/ GAMI's. WOW! Almost hard to believe the difference in EGT-CHT consistency, not to mention how smooth. It's like having a new airplane.
- The new injectors on a TIO-540
Enclosed are the VE injectors I removed from #5 per your instructions, as well as a new chart of the lean test. The new injector pulled #5 very nicely in line with the rest. Engine runs nicely all the way down to 12 GPH.
I was quite pleased with the result after changing to GAMIs. I was very impressed to learn that you weren't satisfied with the result. I really appreciate your perfectionist attitude and professionalism. Great product too!
Curtis LaubDatasheet #1 | Datasheet #2 | Datasheet #3
- Ticking away nicely
Freshly overhauled engine istalled in S-35 Bonanza (N6108V) on 4-10-99. Engine has new millenium cylinders, GAMIjectors, Insight 602 engine monitor, and a new McCauley 3-Blade Prop. Currently breaking in about 11hrs T.T. Runs as smooth as a Rolex watch, with EGT's and CHT's normal and even. VERY SATISFACTORY!
- Tuned Induction System?
Put the reman in around 9/1 or so. Spoke with Mack who agreed with my mechanic that it may be best to start out with the stock injectors just in case there was a warranty issue in the first month or so. He thought the GAMI's might complicate the claim. With TCM, supposedly, about to offer the same thing, this will no longer be an issue. Anyway, during the break in period I was impressed with how "almost" even the temps were. Much closer than the old engine. I even thought that maybe TCM had started putting the balanced injectors in without officially announcing it. About 2 weeks ago we put the GAMI's in. No comparison. The temps are dead even.