Frank N821BF
Active Member
I have a Lyc O-320 in my 9A and was wondering if anyone has changed to fuel injection, was it worth the effert!
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carb to injection
- Thread starter Frank N821BF
- Start date
gmcjetpilot
Well Known Member
Carb to FI conversion
A friend did a FI conversion using a after market Performance fuel injection kit, not the Precision or Bendix brand. If you really want it, it can be done and you have 2 choices of new FI kits or a used overhauled Bendix system. Don?t forget the high pressure mechanical and electric pump. Both these pumps will need to be changed.
Not sure if you are saying: Is it hard to do the conversion itself? or What?s the difference pros/cons, between FI and Carb?
My opinion is leave it alone. Why do you want to change? Are you going to do sustained inverted negative G flight? Are you going to fly IFR, in freezing IMC and concerned about carb ice? DO you have several Grand to spend? You plane won?t be faster or burn that much less gas to justify the several Grand, even if you own your plane for the rest of your life. There are advantages to FI, but at an expense. It is like Fixed pitch props, Carbs are simple and work real well, cheap and last a long time.
My friends O-320 FI conversion was more difficult; His cylinders did not have the injector ports pre drilled, so he had to get them drilled for fuel injectors on the top. He had the primer line ports only, which are towards the bottom. You can get injector kits to use the primer ports, but it is messy. He knew a machinist and also had the specification for the hole in the cylinder. He was rebuilding his engine so pulling the cylinders was not a hardship. Otherwise he is happy, but he has inverted oil and likes to fly up-side down for extended periods in cruise, which is a little silly. RV?s don?t cruise upside down very well.
George
A friend did a FI conversion using a after market Performance fuel injection kit, not the Precision or Bendix brand. If you really want it, it can be done and you have 2 choices of new FI kits or a used overhauled Bendix system. Don?t forget the high pressure mechanical and electric pump. Both these pumps will need to be changed.
Not sure if you are saying: Is it hard to do the conversion itself? or What?s the difference pros/cons, between FI and Carb?
My opinion is leave it alone. Why do you want to change? Are you going to do sustained inverted negative G flight? Are you going to fly IFR, in freezing IMC and concerned about carb ice? DO you have several Grand to spend? You plane won?t be faster or burn that much less gas to justify the several Grand, even if you own your plane for the rest of your life. There are advantages to FI, but at an expense. It is like Fixed pitch props, Carbs are simple and work real well, cheap and last a long time.
My friends O-320 FI conversion was more difficult; His cylinders did not have the injector ports pre drilled, so he had to get them drilled for fuel injectors on the top. He had the primer line ports only, which are towards the bottom. You can get injector kits to use the primer ports, but it is messy. He knew a machinist and also had the specification for the hole in the cylinder. He was rebuilding his engine so pulling the cylinders was not a hardship. Otherwise he is happy, but he has inverted oil and likes to fly up-side down for extended periods in cruise, which is a little silly. RV?s don?t cruise upside down very well.
George
Frank N821BF
Active Member
Carb to FI
Thanks for the reply, I'm trying to get some input on the subject. I have heard that you can do a much better job at leaning with FI than a Carb. I'm also trying to get some feed back on an Ellison unit.
Thanks for the reply, I'm trying to get some input on the subject. I have heard that you can do a much better job at leaning with FI than a Carb. I'm also trying to get some feed back on an Ellison unit.
brianwallis
VAF moderator
cost
I'm looking at trading my yankee for a -3 without fuel injection... and I'm wondering about the cost... it's an old 0-320 from a tri-pacer at 160 hp. I forgot to look for carb heat but I want to convert to FI... any suggestions from anyone on the system to use and the cost?
Best
Brian Wallis
ps.. I just found a thread that talks about the conversion .... 3-5 grand... phew.... any recent experience is appreciated...
I'm looking at trading my yankee for a -3 without fuel injection... and I'm wondering about the cost... it's an old 0-320 from a tri-pacer at 160 hp. I forgot to look for carb heat but I want to convert to FI... any suggestions from anyone on the system to use and the cost?
Best
Brian Wallis
ps.. I just found a thread that talks about the conversion .... 3-5 grand... phew.... any recent experience is appreciated...
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Bryan Wood
Well Known Member
yes you can
Bart from AeroSport talked me out of this at Osh. They have a slick setup that even comes with an adapter so you can use your fab airbox. He convinced me to save it for overhaul if I just have to have it.
Bart from AeroSport talked me out of this at Osh. They have a slick setup that even comes with an adapter so you can use your fab airbox. He convinced me to save it for overhaul if I just have to have it.
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For the money spent, Electronic Ignition will buy you a greater return (if you don't already have it).
On a previous plane with an O-235 I was able to routinely lean LOP at altitude, with only a few degrees temp difference between cylinders. It also ran smoother, started easier, and was probably easier to install.
If you are buying an engine new, it doesn't seem to be that much more to go with FI - so might as well. For upgrades, I'd leave it alone unless you fly a lot of hard IFR.
On a previous plane with an O-235 I was able to routinely lean LOP at altitude, with only a few degrees temp difference between cylinders. It also ran smoother, started easier, and was probably easier to install.
If you are buying an engine new, it doesn't seem to be that much more to go with FI - so might as well. For upgrades, I'd leave it alone unless you fly a lot of hard IFR.
AlexPeterson
Well Known Member
I have FI, so I am biased, but for real world reasons. Would I change to it if I woke up tomorrow and my plane magically had a carb? Depends.
There are a lot of variables defining whether or not FI makes sense. Obviously, you aren't interested in the inverted capability since the plane is a 9A. So, fuel economy might be a reason. There are tons of posts in this forum regarding fuel distribution, leaning, cylinder head temperatures, etc. as they relate to carb/FI, mixture balancing. Some have found great leaning capability (meaning good fuel mixture distribution between cylinders) with carbs (search for PeteHowell carb lean and have a look). Lots of opinions posted. Lots of enemies of FI for whatever reasons.
Best is to fly side by side with someone with an otherwise identical plane, but with a balanced FI, and see what the fuel burn comparisons can be without roughness in the engines (at appropriate <75% power settings). CHT balance is another important variable. Many will have one or two cylinders right in the hottest regime when one or two go rough due to leaning, compelling the pilot to dial in an excessively rich mixture to smooth out the engine. I believe this is the core of the reason why, in the real world, when I'm flying next to a carb'd RV4 or 6 or 8, I am burning 1 to 1.5 gph less. The typical Lycoming mixture distribution is terrible. Some aren't, but most seem to be.
There are a lot of variables defining whether or not FI makes sense. Obviously, you aren't interested in the inverted capability since the plane is a 9A. So, fuel economy might be a reason. There are tons of posts in this forum regarding fuel distribution, leaning, cylinder head temperatures, etc. as they relate to carb/FI, mixture balancing. Some have found great leaning capability (meaning good fuel mixture distribution between cylinders) with carbs (search for PeteHowell carb lean and have a look). Lots of opinions posted. Lots of enemies of FI for whatever reasons.
Best is to fly side by side with someone with an otherwise identical plane, but with a balanced FI, and see what the fuel burn comparisons can be without roughness in the engines (at appropriate <75% power settings). CHT balance is another important variable. Many will have one or two cylinders right in the hottest regime when one or two go rough due to leaning, compelling the pilot to dial in an excessively rich mixture to smooth out the engine. I believe this is the core of the reason why, in the real world, when I'm flying next to a carb'd RV4 or 6 or 8, I am burning 1 to 1.5 gph less. The typical Lycoming mixture distribution is terrible. Some aren't, but most seem to be.
mannanj
Well Known Member
FI
Frank:
If you want to talk to a real world Fuel Injection Guru, call Don Rivera at Airflow Performance. His ad is on the left side of this page. Don will give you knowledgeable, straight answers with no BS.
I have no relation to his organisation other than a very satisfied customer. For what little money I have spent on his products and services, Don has spent a lot of time on the phone answering my dumb questions.
Currently he has spent a good deal of time on the phone and via e-mail assisting me with matching the restrictor nozzles on my fuel injection system to match the "GAMI" injector system so I can run Lean Of Peak without worrying about frying my engine.
My $0.02, go to the source.
Frank:
If you want to talk to a real world Fuel Injection Guru, call Don Rivera at Airflow Performance. His ad is on the left side of this page. Don will give you knowledgeable, straight answers with no BS.
I have no relation to his organisation other than a very satisfied customer. For what little money I have spent on his products and services, Don has spent a lot of time on the phone answering my dumb questions.
Currently he has spent a good deal of time on the phone and via e-mail assisting me with matching the restrictor nozzles on my fuel injection system to match the "GAMI" injector system so I can run Lean Of Peak without worrying about frying my engine.
My $0.02, go to the source.
I was about to do the swap and bought the kit from Aerosport, but never actually installed it. There are a few things to bear in mind.
Make sure your cylinders have fuel injection ports drilled.
You will need a new fuel pressure sender.
Your manifold pressure tapping may now flood with fuel.
You will have to completely re do the fuel system around the electric pump.
You may require different length throttle and mixture cables.
You will require a new bracket to secure the cables.
If my airplane had been closer than an hour away, and if I had not had to do a ton of other stuff, I might have gone ahead with the mod. FI definitely saves gas as its much easier to run lean of peak.
Pete
Make sure your cylinders have fuel injection ports drilled.
You will need a new fuel pressure sender.
Your manifold pressure tapping may now flood with fuel.
You will have to completely re do the fuel system around the electric pump.
You may require different length throttle and mixture cables.
You will require a new bracket to secure the cables.
If my airplane had been closer than an hour away, and if I had not had to do a ton of other stuff, I might have gone ahead with the mod. FI definitely saves gas as its much easier to run lean of peak.
Pete
Another concern you should have is proper engine cooling.
I am aware of an RV-6A built many years ago with a turbo'd engine.
When the builder finally got the engine to cool well enough at altitude, the cowl had round air inlets that were about 8 inches in diameter.
I do not know any other details (not sure if he adapted an intercooler, etc.)
Cooling a turbo'd engine in lower density air at higher altitudes while it is still producing a lot of power is a challenge.
Lots of RV pilots fly all over in the ruggedest parts of the North America rocky mountains with non-turbo'd RV's. Is the terrain in Mexico that much different than North America? Most of the Rockies I have flown in also have alternate landing sites few and far between. An RV-7 with 180-200 HP and a constant speed prop has fantastic performance in the Rockies without a turbo. I don't think it is worth the expense, weight, and additional failure point, not to mention the development process you will have to go through just to make it work.
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N941WR
Legacy Member
Isn't this this the reason the FAA is jumping all over the homebuilt regs?
Not trying to be a PITA but I had to ask.
Also, since you want to go high and don't care about acro, the -9A would probably be a better plane because of its longer wing. Truth is, the speed difference between a -7A and a -9A is almost nil and yet on the same power, the -9's service ceiling is higher.
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The TIO-360 is a different animal for an RV than what the other 5000+ RV's have on them. Not only is cooling going to be in issue to design around, but so will the systems in their entirety. You need to determine if it's going to be turbocharged or tubronormalized, work out a wastegate system (manual or automatic) fuel delivery/metering, etc.. There are a lot more mechanical issues than just making the thing fit under the cowl. Then, there is more weight up on the nosewheel - which the "A" models don't need more of..., finding the right prop for that engine on an RV (which I don't think has been tested yet), and finally the speed issue that Van himself spoke to in a past RVater issue.
Also, if your builder has not done an RV with a Turbo'd engine on it, I sure as heck would be VERY carefull about who you choose....it's bad enough to be a guinea pig on an airplane you build yourself, but at least you know it down to each and every rivet. If you purchase a pre built airplane, you absolutely need to have every confidence that the builder knows what he's going when it comes to RV's, Turbocharging, test flying, etc..
My advice - though the TC'd idea sounds rather attractive, I'd just skip it all together. As others have said, the RV's do not suffer at altitude like many factory planes.
My 2 cents as usual!
Cheers,
Stein.
BTW, in the interest of full disclosure...my current project has a supercharged engine. Just not something I'd do on an RV.
Also, if your builder has not done an RV with a Turbo'd engine on it, I sure as heck would be VERY carefull about who you choose....it's bad enough to be a guinea pig on an airplane you build yourself, but at least you know it down to each and every rivet. If you purchase a pre built airplane, you absolutely need to have every confidence that the builder knows what he's going when it comes to RV's, Turbocharging, test flying, etc..
My advice - though the TC'd idea sounds rather attractive, I'd just skip it all together. As others have said, the RV's do not suffer at altitude like many factory planes.
My 2 cents as usual!
Cheers,
Stein.
BTW, in the interest of full disclosure...my current project has a supercharged engine. Just not something I'd do on an RV.
Many people would say that you would be better served by an IO-390 (Lycoming) or IO-400 (Superior) than by a turbo. Only a few extra pounds, and you can squeeze a few more horsepower out by going with high compression pistons (but then you cannot use auto gas). Use electronic ignition and a lightweight C/S prop, and you will still have good climb performance up high.
When I think rugged terrain and possibly regular flight in and out of unprepared strips, I think "reliability." A turbo is another point of failure.
My 2 cents worth.
When I think rugged terrain and possibly regular flight in and out of unprepared strips, I think "reliability." A turbo is another point of failure.
My 2 cents worth.
