I see all kinds of advantages to fuel injected like NO carb ice, better fuel mileage, 20 more hp when done on a O360, leaning on the lean side of peak. So what are the disadvantages? There must be plenty because I don't even remember seeing a cub with an IO360.
Aside from the parallel valve to angle valve difference? Electric high pressure fuel pump and mechanical fuel pump. Lycoming hot start woes. If EXP go with API zero leak-down servo or EFI. Add Electronic ignition. Cold air induction. There’s no end for places to spend money.
My Cub has an IO-390. I have friends with 409s. There’s more to it than increasing HP.
Last edited by stewartb; 11-04-2022 at 08:56 PM.
I don't think the 20 more hp in the IO 0360 is from fuel injection. Denny
One of the downside is need for fuel pump. Gravity never needs a backup or 12 volts to work. Carbs work well on mogas. No right or wrong just things to think about.
DENNY
I just put an airflow performance FI on an 0360.
Added complexity as mentioned, there’s really no performance gain, unless you consider flying inverted a performance gain.
don’t think you’ll be able to get a 4 cyl to run lean of peak like a 6 cyl so, minimal fuel savings.
Every guy WITH angle valve-fuel injection and an electric fuel pump laughs at the comments from guys who don’t. Mogas works with low compression. It has nothing to so with fuel pumps or FI. Seriously. If you want big fun and have a budget for a CS prop? Go angle valve with FI, EI, and high compression. 235+ HP is fun.
Last edited by stewartb; 11-04-2022 at 09:29 PM.
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Look up the weight between a 0360 and I0360, I am not a weight fanatic but some are.
DENNY
Guys that own them might have looked. I wouldn’t go back. But what good is a pirep when you have imagination?
Big Cubs need big HP. If you’re into replicubs? Stay with legacy engines.
Lots of Cub clones with IO-360 but most may be experimental.Originally Posted by The Kid
My YIO-360 (CC-363i) seems to be quite happy LOP.
Ha! A member here can run his IO-409 so lean of peak he had to make louvers to limit airflow because his cruise CHTs were too low. How many of you have that problem? Pardon the pun, but how cool is that?
You don’t know what you don’t know.
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Ah yes the Lycoming name game. An O-360 can make 180 hp and and IO-360 can make 200 hp but it's not the same engine with injection instead of carb. CubCrafters parallel valve injected 360 Lycoming (CC363i) makes far less than 200 hp.
I doubt an injected parallel valve engine is any heavier than a carburetted parallel valve engine. The difference is probably no more than the weight of the two fuel pumps. The difference in power is just as small but I'd still rather fly the injected engine.
Last edited by frequent_flyer; 11-05-2022 at 07:27 AM.
Is the same true true with big continentals? Can I run mogas with 7.5-1 pistons with mechanical fuel injection in a I0-520 instead of recommended 8.5-1pistons?
Check out the Mogas STCS for engine applicabilities. Peterson and EAA.
Gordon
N4328M KTDO
My 7.5-1 PPonk runs fine on mogas. I use 100LL for normal ops but I haven’t found any problems with mogas when that’s all there is. It’s science. It’s all about compression.
10:1 on your EXP? Have you experimented with 91 octane ethanol-free Mogas?
Gordon
N4328M KTDO
Nope. I keep 100LL in my home tank. No reason to tempt fate. My engine is a beast. I feed the beast 100LL.
Kid,
There are no differences when converting between the 0-360 and the I0-360 other than carburetion or fuel injection. Converting from the 0- to the IO- does not change the horsepower. I have an IO-360-B1D in my experimental Cub. It is 180 hp and is placarded on the data plate to use 91 octane minimum. The IO-360-A engine is 200 hp, but there are many more changes than just fuel injection.
If your plane is experimental https://airflowperformance.com can modify your fuel injectors with removable orifices so that you can tune the fuel flow. The process is described on their web site. Having done this along with electronic ignition you can lean anywhere along the mixture curve rich or lean of peak EGT, to as lean as the engine is just slowing down until it stops from being too lean. ALL without any roughness.
If your Cub is certified, https://gami.com/gamijectors/gamijectors.php has certified balanced injectors.
Hot starts are a no brainer when you understand the system. On very hot days when running at idle on the ground it can run rough due to the vaporization of the fuel in the hot lines over the engine... even to the point of quitting. Solution ... turn on the electric fuel pump. This pressurizes the fuel in the lines.
I'm not aware of a certified Cub modification to fuel injection. I suspect (without looking into it) that you would need to get a one time STC since it involves altering the fuel system. Perhaps a DER can give you a field approval?
In my opinion there are no disadvantages to fuel injection.
I agree with Pete. Take a look at Lycoming's web site, and start looking at different engine models.....there are dozens of these little four cylinder engines.
Big difference between the Lyc. IO 360 180 and 200 hp "standard" engines is that the 200 uses an angle valve engine, as Stewart keeps referring to. Other than cylinders, the big difference in the angle valve engines is that they have crankshaft mass balancers, which are heavy. But, as Pete says, Lycoming makes parallel valve IO-360 engines, rated at 180.
Then you get off into a whole plethora of relatively new engines, most of which are experimental, but not all. For example, the Continental IO-372 is essentially a modified Lycoming IO-360, and it's certified. That's one of the engines that Stoots uses in his Cessna 170/172/175 engine mods. AOPA is putting one in the Sweepstakes 170.
That engine is relatively light (parallel valve) and makes a LOT of power. Put one in a certified Cub? Get an STC.
Put me in the group that sees few down sides to fuel injection.
MTV
“I doubt an injected parallel valve engine is any heavier than a carbureted parallel valve engine. The difference is probably no more than the weight of the two fuel pumps. The difference in power is just as small but I'd still rather fly the injected engine.”
Jay DeRosier at Javron, had an opportunity to weigh all of the fuel injection system, and then weigh all of the carbureted system, and fuel injection is close to 20 pounds heavier than carbureted. He tried very very hard to make an apples to apples comparison.
Injection is a great and wonderful thing and it certainly has its application. So does light weight and simplicity. It just depends on your mission what you want.
Last edited by Bill Rusk; 11-05-2022 at 09:27 PM.
Very Blessed.
Perhaps when you figure two fuel pumps, flow divider, lines and injectors. But, you can figure on using at a minimum of 30 pounds less gasoline on every fuel tank fill up. So when you figure in the fuel savings there is a minimum of 10 pound advantage to fuel injection. I use about 2 gallons per hour less (60 pounds per fill up, leaving a 1 hour reserve) in my fuel injected Cub than I was ever able to manage with a carburetor in other airplanes I've owned.
Bill,
Is that weight difference analysis available anywhere on-line? I had a quick look but didn't find it. AVstar doesn't seem to publish a weight for the AVX360-1 kit. I do know my Andair electric pump is less than 1 lb.
thanks
I had estimated about a 10lb gain from weighing some components but I didnt have everything available to weigh. Im also in the camp of FI. More HP under adverse conditions like high density altitude, better fuel economy, smoother engine operation. It is technology that is almost a hundred years newer than carburetors. My current build also has a manual primer so an electric fuel pump is not required to start the engine.
I would place a bet that after pilot error and fuel exhaustion, carburetors are the #1 reason for engine failures. (Ive had Carb ice, stuck floats, separating components, and definitely dont actuate that accelerator pump too quickly on a go around). Every problem I fight with my lawn equipment is a carb issue too. I dont even want a carbureted lawn mower!
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I love super cubs and wouldn't have anything else. What an airplane and what it will do is legendary. And contemporary improvements too like electronic ignition, fowler flaps, composite adjustable propeller and more. But our engines are 100 years old in technology. What a crying shame. I know some of the corvettes are fuel injected with computers that sense altitude and power and adjust the fuel accordingly and even deactivate half the cylinders when the power isn't required. And get over 22 mpg with hundreds of hp. And I'm screwing with proper mixture settings, poor mileage and carb ice. I would expect that on a 1920 tractor but not on my "dream machine".
You’re certificated? You’re screwed. Exp? No limits. You can get precise fuel delivery (and MUCH more) without asking for permission.
Both O-360-A and the IO-360-B series engines have parallel valves cylinders and are generally 180 hp. The IO-360-A series engines have heavier, more powerful Angle Valve cylinders (200hp.) Lycoming's TCDS lists the weights of the 0-360-A's around 258 pounds and the IO-360-B's around 268 pounds. IO-360-A with angle valve cylinders are around 296 pounds.
I have an experimental O-360-A engine that was build up with Bendix Mechanical Fuel Injection instead of a Carb. So its very similar to an IO-360-B series with a sump set up for a vertical mounted servo. I can't imagine 20 pounds extra for FI is right. I can see most of the extra weight coming from one engine driven fuel pump and one electric fuel pump. I can see the flow divider weighing about 2 pounds, and the I bet the servo is close to a MS carburetor. Ten pounds extra seems about right to me. But what do I know?
My engine with the Vetterman exhaust, two mufflers for heat, a BandC belt driven alternator and starter, one Bendix Magneto weighed 307 pounds, measured with a digital hanging scale.
An engine builder like Bob Barrows will build an experimental engine from Lycoming Parts to new engine tolerances for the experimental builder in accordance to what they desire, within reason. What kind of Cylinder? What kind of Fuel Delivery? What kind compression? Narrow or wide Deck case? Do you want a Prop Governor, Vacuum pad drive? You wont find a certificated low compression Angle Valve Carbureted engine, but Bob will build one to burn Auto Fuel.
Economics favor Fuel Injection significantly. Simplicity favors a Carb. Reliability - you tell me. I hear that EI eliminates the hot start issue. If I had a carb, it would eliminate the electric standby fuel pump. Then I could see leaving off the Alternator and have a battery operated electrical system for the starter, COMM radio, and maybe Lights for evening flight during civil twilight. But then I can't go as far, and it cost more fuel, and may loose some weight carrying capacity on long flights. Define your mission. I am an efficiency nut so I like FI with API balanced injectors to run lean of peak sparked with EI.
Yeah, I'm certified. I should build myself a Javron. Trouble is I have difficulty opening a box of cereal. I don't think it would turn out well.
“The Kid”, better sell me yours and have Chuck build you a Javron
I would love to see the details of this comparison. The two fuel pumps aren't that heavy. The FI servo must be about the same as a carb. Different sumps? The spider and distribution tubes don't weigh much, and the carbed engine needs a primer.
If it ain't broke - improve it
So, myself not being a mechanic, is there a FI engine, that runs by a computer like or somewhat like a corvette does, that senses most everything and adjusts accordingly, that I could put in an experimental where I don't need to lean as it does it all by computer? FADEC rings a bell? Or just put the corvette engine in with gear reduction, but that would be too heavy I am sure?
SDS or EFII electronic fuel injection with their respective CDI ignitions are as close as you can get, and overall should be lighter than carb and mags, even with a back-up battery. Most of us that have provided pirep comments have mechanical injection. Electronic injection raises the bar even higher for performance and efficiency.
http://www.sdsefi.com
https://www.flyefii.com/products/efii-systems/
NX1PA
I have Emags and Silverhawk (mechanical) injection. Originally I had planned EFII, but the complexity of the system and installation scared me away. It will require a return fuel line and quite a bit of additional hardware/electronics mounting. Something to look into if you go that route.
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Also according to Aerosport power you can run mogas with 9:1 compression with the EFII system so another advantage there
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I asked Avstar for the weight of the AVX360-1 kit and they replied with a shipping weight of 8-9 lb. Obviously that will be a bit more than the weight of the components.
Let's say 9 lb for the servo, divider, and nozzles, 1 lb for the Andair electric pump, guess at 1 lb for the mechanical pump, and another 1 lb for fuel filled tubing. That comes to a wildly pessimistic total of 12 lb. Now subtract the mass of the carb and the estimated difference is 11 lb. Neglect the weight saving for removing the primer and primer lines. Neglect any savings for getting rid of a manually controlled air box and using automatic alternate air.
That is slightly more than half the 20 lb difference proposed earlier. What did I miss that adds another 9 lb for injection?
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