Thread: An engine is an engine

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I'm working on an engine in uncharted territory, to my knowledge - no one has done it before. I need help

the engine is a 210 hp horizontal opposing turbo fuel injected air cooled engine.

to those of you who notice something - yes it is an airplane engine and it is going into an airplane.

BUT, i am adding "hot rod" parts to it.

intake manifold - making my own from carbon fiber

exhaust system - making my own from mandrel bent 321 SS tubing with twin turbos

fuel injection - tearing out the mechanical and making my own electronic injection

spark - removing the magnetos and installing my own hall effect pickups and electronic ignition

should i go on - I'm gonna need assistance and ifin you all here want to help - please speak up. nothin bolt on here, figure out and make it, and i better make it good - i'll be flying at 25000 feet in it

Being an A&P myself and now quite heavily involved in the aircraft certification world, I would suggest you thoroughly evaluate the approval means by which you plan on returning this engine to service. These parts and materials and the data you
are going to use for accomplishing this alteration will require FAA approval. I also would suggest you contact your local flight standards office for some guidance on approving the alteration. Alterations to airplanes are a little more complicated than cars, you can't just stick on an aftermarket part and go blasting off into the wild blue yonder, because if that part fails you can't just pull over to the side of the road. Good luck with your endeavor.

no cert needed - i'm in the experimental world - it just has to pass my test.

no backup - i'll have backup and no parachute. the available ECU's are very reliable and i will have a complete electrical system and sensor backup for the engine. on the fuel side - mechanical and continious duty electric backup fuel pump and probably two fuel preasure regulators. if one cam sensor goes, i'll have a backup and if the crank sensor goes - i'll have a backup.

for all other sensors, from MAP to OAT, the ECU tables allow me to put in defaultd.

so it is not going to fly? if you just want it to pass your test's, you will never get off the ground because of FAA's strict inspections. Even the Junkyard wars plaines had to pass FAA regulations.

heh heh heh - yes it is going to fly, my goal is 300 mph TAS at 25000 feet. the FAA inspection is a non event and it will pass, my inspection will be much tougher.

I was have a DAR inspect and he will approve.

but in picking out the individual items to use - i was thinking of passing it buy yous guys - are you into figuring stuff out - or are all of you just bolt it on and see if it goes??

I like to just bolt it on and see if it goes.

It sounds like your hotrod is a little different from what we see here. I too, am an experimental aircraft builder. My preference is sailplanes.
It sounds like you want to increase your prop power without exceding drop off efficiency. Without knowing all the details, and if I did, I might not be that informed, I might consider keeping the mags, stock intake, and going with a redrive. You will have to design it to fit the Lycoming, but, your engine is low compression, very efficient in flow dynamics.
A redrive will shift the power curve of the engine to allow a steeper pitch prop, and larger diameter. Any weight savings eliminating the magnetos, will be absorbed by the other components needed.
I had both sets of points on a Cessna 150 close directly after the airport had serviced the Aircraft. I was a student pilot back then and made a very lucky off field landing during one of my solo cross country flights. It was a text book soft field emergency landing. The FBO even got to fix the points and fly it out! That experience and several others in outboards, automobile engines led me to ask questions about everything untill was worked out, and even then things went south.
I wish you luck, and success.

Yes my "hot rod" is a little different. but what i have learned over the last couple o years is "an engine is an engine" and all piston engines are the same.

that said, a redrive,mmmmm, no i'll just have a constant speed prop. the great thing about an aircraft engine is that it is run, with a cs prop, at just 2 RPM's. in my case 2400 and 2800.

so i can design for max efficiency for just those two rpm's and my job is simpler. i have already had burns stainless do the numbers on the exhaust - i know how long to make each runner and i have the formulas to size the intake runners and plenum.

my goal in this is to make the engine more efficient, both in fuel burn, and need for boost at altitude to "normalize" at 25000 feet and below. also - the magnetos are mechanical money pits and i want electronic ignition.

the reason for the new injection and a requirement of the new injection is to level out the air fuel ratio in each head. i want to make the EGT's within 10 or so degrees of each other, that will allow lean of peak operation

so anyone experienced with ECU's that allow trimming each cylinders A/F ratio?

I have looked at a variety of ECU's and the excel gen 7 will do the trimming. i did not want to post what i have seen - am not trying to have a decision verified - am trying to go out of the box.

I have also looked at mega squirt - not in enough production or testing for my likes. i NEED well tested unit with a MTBF of 100,000 hours and RF and other testing done on it

I think you are way off, saying an engine is an engine. yes they have the same concept of running, with pistions, cranks and rods, and a fuel with combustion. The diffrence is engines that are in plaines are designed to withstand the higher air preassure, I'd bet your mechanicle injection ajust's in major ways to take the high preassure and make the engine run correctly at the high altitude, spark curve and all of that changes with the altitude, you tune a car with a distributor at the altitude it will most see, cars with coil packs and EFI constantly change the spark curve with the altitude changes, as it notes the changes in preassure. I doubt that a production ECU will have ajustments for more than 10,000 feet, you would need to make a custom program

Originally posted by Matt167

The difference is engines that are in plaines are designed to withstand the higher air pressure, I'd bet your mechanical injection adjusts in major ways to take the high pressure

Actually - as you go up the pressure decreases. in a normally aspirated engine, you simply lean the mixture as you go up to stop the engine from running too rich and fouling the plugs.

in my application, i am running turbos to normalize the manifold air pressure up to and including 25000 feet, over that i will have to lean the mixture to avoid running too rich as there will not be sufficient air.

but all ECU's that i have read about can handle that.

good thinkin denny - but i'm goin individual runner injection at each cylinder. it is very important for me to be able to tweak the air fuel ratio at each cylinder to level out the egt's so i can burn Lean of Peak in cruise and maybe even in climb and save engine valve wear. these engines usually have some cylinders burning rich so if i can tweak each one - it will save my valves because the extra fuel condenses out and lands on the valves and wears them out.

imagine what running your engine at 100% power for 10 minutes after startup and then throttling back to just 80% of power the rest of the time would do to it's innards

Motec is a great unit, but really pricey. This option, a small and a large injector is GREAT for a 1,000 hp race car, where the fuel flow change is so drastic that the large bore, is that the right term for a large capacity injector, will not smoothly deliver small quantities of fuel, my engine, altho using 80 to 100 percent of power at most times of operation is not delivering that much fuel that one injector cannot handle both idle and operating loads properly.

btw - one reason not to use the throttle body is for better a/f mixture control, no matter how good i make my intake manifold and how much swirl i put into the inside of it - the a/f ratios that make it to each cylinder would vary too much

Seems like a very interesting discussion of high tech fuel systems and DennyW knows his stuff. My question would relate to a carb intake where a heater is required to keep frost out of the intake and flow jets. I realize the fuel injection squirts under considerable pressure but so far there has been no discussion of any intake heater as to whether that is necessary using this type of injection system. I am familiar with an experimental aircraft that had to crash land due to carb icing because of a faulty carb heater. Is that going to be necessary in this injection system?

Don Shillady
Retired Scientist/teen rodder

carb ice = major problem for carburated airplane engines - you will never see me with a carb on a plane i build - have never heard of a problem with ice on an injected system.

my projected temps - just guesses are

outside temp = -30 F

turbo exit temp = 300 F

temp after intercooler = 30

you are dead on on the EGT probes - one per tube, but, i will not run closed loop as if a sensor fails i cook the engine. the tweaking of the fuel will be done during testing, first on the ground and then in the air, the tables will be built and then the egt's will be for my info and not for closed loop operation. i do plan on using closed loop wide band ox sensor, but one problem, two separate exhaust pipes and one sensor and the ecu does not seem to be able to accept input for two separate banks of cylinders. whew - this stuff is complicated.