Below please find a long post about EFI on aircraft engines, VW and otherwise... Also a 2011 email addy for Les.This info was posted by Les Smoot to the Aerovee list sometime ago.
In
aerovee@yahoogroups.com
, "Les" <soloflyer62@yahoo.com> wrote:
> Group,
> I have two 2180's running EFI. One is on my Sonari,
> it's an early Aerovee, single ignition with a 10 amp
> alternator. The second is VP-1 with a Great Plains 2180
> ....same exact engine as the Aerovee ...a VW is a VW!
>
> Everyone should go to the CB Performance webpage and
> download their catalog. You will see a lot of familiar
> engine parts there.
>
>
>
> My new 2180 Aerovee will go in my Sonex ....it too has
> the EFI.
>
> The EFI is a direct port injection type, an injector
> in each intake port ...and a small 34mm throttle
> body where the carb would mount. I use intake manifolds
> sold by CB Performance that already have the ports
> for the Bosch type injectors built in and a provision
> to support the fuel rail. It is a speed density system,
> it injects fuel based on load (manifold pressure) and
> rpm .....can be used with or without an O2 sensor.
> On my new Aerovee I drilled the Aerovee intake manifolds for
> the fuel injectors, ended up with a very clean setup.
>
> CB Performance makes an EFI system, which I used on
> an early Aero VW engine, ran great but the electronics
> package was NOT of aircraft quality, an even worse
> EFI system is the MegaSquirt system ...it's junk! If
> you are going to put an EFI system on an aircraft
> engine use the SDS system, it's the only one out there
> that has been designed with possible aircraft use.
>
> I have tried Haltech, Holley, MSD .......they are nice on
> cars, but not aircraft quality.
>
> The EFI system is made by a company in Canada called
> Simple Digital Systems (SDS for short). I was exposed
> to their product several years ago in the military,
> we used this system on the Predator UAV (unmanned aerial
> vehicle). It is a stand alone fuel injection system
> that is aerospace quality, uses a small hand programmer
> to edit the fuel map. The system is so flexible you
> could put EFI on a weedeater if you so desired! I spent
> alot of time with this sytem, and currently have several
> automobiles, a speedboat and several airplanes with
> this system ......the ECM is very small and mounted in
> a billet aluminum housing, the whole system will add
> 4 pounds to the engine/aircraft, and that's because I run
> dual electric fuel pumps in parallel for redundancy. The combo
> (injectors, pumps and ECM) pulls just over 4 amps total a
> 3400 rpms.
>
> The VW runs very very well ....and will leave a carburated
> VW in the dust! All of my aircraft have made several yearly
> trips to Sun-n-Fun ...1300 miles round trip...never had
> any engine or EFI related failures! I expect the same reliablity
> out of my Sonex.
>
> My new EFI 2180 Aerovee powered SONEX will fly soon,
> the engine is already running on the test stand
> with 10 hours of break in time on it so far. It's
> the same Aerovee kit, but with someone elses (GP's)
> purpose built crankshaft and prop hub .....as I won't
> fly shrink-fit hubs anymore......we beat that dead
> horse to death last month. The crankshaft and hub is
> the only thing I didn't like about my Aerovee ...so I
> fixed that.
>
> The EFI ECM has a limp home
> mode, uses only 3 sensors, a throttle postion sensor,
> MAP sensor and CHT senor, the engine will keep running
> if one of these fails .....I already mentioned the
> dual EFI fuel pumps, if one fails the other keeps running
> ....but that has never happened either! These small
> automotive electric fuel pumps will run forever if you
> keep the fuel clean, and the ECM is extremely reliable,
> the engineer who designed it has only had 2 fail out of
> several thousand in 8 years, and out of the 2 that failed
> one of those was connected in reverse polarity and burned
> up, installation error, that leaves one failure ......and
> it lost one injector driver and the engine kept running on
> the other 3 cylinders.
>
> I have learned over the years that 7.5 to 1 CR works
> very well on VW's with EFI, I can burn auto gas or Avgas,
> and I prefer Avgas ....but in a pinch auto gas will get
> you home.
>
> The slightly lower compression is easier on the engine
> especially exhaust valves. The EFI tends to compensate
> for the slightly lower power compared to the 8.0 to 1
> CR engine. EGT's run in the low 1200's consistently,
> they almost never change ...a tribute to the EFI. Like anything
> else, if you don't place the probes correctly you can
> have readings vastly different ......It should be noted
> here that with all things being equal EFI does not really
> make any more HP, but compared to a carb the precise mixture
> allows the engine to more efficient, thus perform better. If
> you are totally satified with your carb engine then you should
> avoid EFI, but this is the single best improvement I have
> seen yet on the aero VW, it will make you think you have a
> new engine under the cowl....the engine will run totally
> differently.
>
> I am no expert but I am no novice either, I have close to
> 700 hours flying behind EFI VW engines alone, it's proven
> so far to be overall more reliable than a carburated engine.
>
> I did not say it was any safer ......I said for me it
> has proven to be more reliable .....because there is less
> maintenance to the engine as a whole. Once installed you
> don't ever have to mess with the EFI again. Plugs don't fowl,
> oil stays cleaner .....less cockpit controls. A lot of
> other maintenance goes away with EFI ......if you have ever
> had an engine that always needs something tweaked, a leak
> fixed, you will know what I mean.
>
> In 20 years of flying VW airplanes I have had some carb issues ...
> but to date I have never had an EFI issue .....but that does
> not mean I won't! Anything can fail.
>
> My EFI VW starts with one revolution of the prop, has better fuel
> economy, no carb heat or mixture control, the engine never
> overheats, the oil stays cleaner, the plugs look like new
> even when I change them at 100 hour intervals. When I
> pulled the heads and cylinders at 500 hours I was amazed
> at how little wear there was, on other engines with carbs
> they were carboned up and always at least needed a valve job
> and cylinders ......I simply ground the valves because it was
> already apart and I re-ringed the same pistons and put it back
> together ......I will pull it down again at 1000 hours. Again,
> I was surprised because 92mm cylinders have a thinner wall
> thickness and normally wear rather quickly. These looked
> great, and I have seen what happens to lots of 92mm cylinders
> over the years ......I would bore the case for 94mm cylinders
> but that can cause problems with the case ......if you want
> reliability stay with the 90mm's or 92mm's .....94mm cylinders
> get too close to the case savers for my taste .....Aerovee knew
> this too when they did not go with the larger displacement engine
> which uses 94mm cylinders.
>
> The cylinder to cylinder fuel charge is exactly the same,
> (unlike carb engines) .....during a recent top end on the
> Sonari for example, at 500 hours the cylinders had
> almost no wear ....why... Because with a carb engine when
> you run rich, you wash down the cylinders ....all of that
> extra fuel washes the lube oil from the cylinders, the bore
> wears, the pistons wear, the rings wear .....the
> fuel will also delute the oil and make it thin and
> dirty ........EFI will make your engine last longer due to
> cleaner and more complete combustion and this produces less
> wear.....it burns cleaner because the
> mixture is precise, an injector for each cylinder
> makes that happen, there is no fuel to settle out of
> the mixture in that long intake manifold ...there is
> nothing in the intake manifold but air .....an intake air
> leak does not cause a lean mixture, it just causes the
> engine to idle slighty faster ....that's one way you
> know you have an airleak .....what ever air the engine
> pulls the ECM just adds the correct amount of fuel to keep
> the mixture right.
>
> The throttle response is amazing ......Other than
> for emissions reasons why do you think auto engines now
> routinely use EFI and go 200,000 to 250,000 miles before
> overhaul, this is largely due to EFI ......and the
> precisely metered fuel.
>
> Everything that makes EFI great in a car applies to
> airplanes too! Yes, it's slightly more complicated, yes
> the fuel system has a few more components .....but there
> are things that make this system just as reliable as
> a gravity fed carb ......mostly proven out by the millions
> of automobiles using EFI.
>
> There are pros and cons .......and someone could argue
> how the simple gravity fuel system and a carb are hard
> to beat ....maybe, but I wanted something modern and
> I wanted fuel injection, there are too many advantages
> not to use it. My engine will make more power,
> run better, get better fuel economy, with less internal
> wear, starts instantly, a near perfect mixture all the time,
> the list goes on and on. It's a great system, it's not a
> right or wrong thing, it's just different .......I work
> on these systems every day ...and I understand them, yes
> there is some added complexity ....but less maintenance and
> everything is automatic, just hit the starter button and
> not worry about mixture ....or carb heat. If there was a
> con to me it's cost, this system is not cheap, you get
> what you pay fopr with these systems ............I know I
> own a few EFI systems. It will cost about $1100 to add EFI,
> and do it the right way with high quality hoses and fittings,
> don't skimp here ......or it will burn you!
>
> Other things;
>
> If the alternator fails the engine will run for about
> 15 minutes giving you time to land .....I get an alarm
> the instant the alternator drops offline...and with a small
> 18 amphour backup battery you can extend that to 30 minutes,
> but in 5 years I have never had that happen, but I have a
> simple system in place to warn me and keep me flying until I
> can land. I can flip a single switch and divert all power
> to the fuel pumps and ECM .......I ground test this often
> and replace the battery when run times drop below 30
> minutes with the alternator turned off. A blocking diode
> allows charging of the backup battery all the time, but only
> the EFI can draw from it, a very simple backup solution.
>
> The ECM sets the fuel mixture based on load (manifold pressure)
> and rpm ......when the outside temperature changes it
> adjusts the mixture. There is an option for an O2 sensor
> but that really just improves cruise fuel economy a bit,
> it auto leans the engine during cruise, if you move the
> throttle the O2 sensor drops offline until cruise flight
> is re-established.
>
> I don't use an O2 sensor except to check the air-fuel-
> ratio every 100 hours ....it's a maintenance thing! I go
> through the entire rpm band from idle to WOT and make sure
> the ECM is keeping the mixture correct. I use an AFR meter
> and mines uses an O2 sensor to sniff the mixture. I may
> replace the instrument panel EGT meter with an AFR meter
> in my Sonex ......no need to monitor EGT anymore! Oil
> temp and CHT are my primary concerns with VW based engines.
>
> EFI engines run and start just as
> well at 20 degrees as they do at 90 degrees and require
> no choke ....just like your automobile it runs smooth
> as silk .....as a side note, I can also run my engine
> on ethanol / methanol with a quick change of the fuel
> map program within the ecm ...takes less than 5 minutes!
> The engine runs 80 to 100 degrees cooler and makes more power,
> but burns 42% more fuel to do it as the BTU value of
> alcohol is less than gasoline .......but it is fun, not
> something I plan to do often, but it's a neat alternative
> fuel and yes I know all about the moisture issue with
> alcohol fuels! I drain my tank and flush the fuel
> system with gasoline after using alcohol fuels .....!
>
> One of my EFI VW engines on the test stand was run at the NC
> State Fair this year as a demo using denatured ethanol for the
> agriculture comission. It was run about 10 hours over a
> 10 day period of time. NC is going to be a big ethanol and
> E-85 state ......I had several hundred guys try to buy it off
> me ......but we showed them how to build there own ....On alcohol
> the VW will turn a prop with 3 more inches of pitch at the
> same rpm .......
>
> There are many airplanes flying EFI ....not just VW's. My
> hangermate has this EFI system on his RV6 with an IO-320 ......
> been flying it for over 400 hours ......
>
> Not trying to convert anyone to EFI here, just sharing! Thought
> some of you may find it interesting. If EFI is NOT something you
> are interested in, then ignore this post ......I do my own thing
> and I have the skill set to pull it off, and as an A&P I know how
> to do this safely! It's not for everyone ......
>
> The SDS webpage is here for the looking. Look in the
> airplane section, one of my smaller planes with a miltary
> GPU engine(4A084)is in there .....it's just a baby VW at
> 45 hp. The system is the SDS EM-4 system, will support
> just about any 4 cylinder engine.
>
>
>
> If you are still curious contact me offline, don't want to
> tie up this site with EFI stuff.
>
> Sorry for the long post.
>
>
> Les
> NC Sonex#1094
