I Finally Figured It Out

That's what my dad always used to say, "I finally figured it out". He was always talking about the meaning of life. In my case, I just want to figure out how to make the damn engine run.

Thanks to Lynn French, I definitely know the ignition problem is due to my trigger wheel and sensor assembly. Lynn was kind enough to lend me his parts, while his engine is down, and I bolted it on this afternoon. Lynn has the 7" trigger wheel, while I have the 6". I used my existing sensor and wiring.

The engine fired up just fine, as always. After it warmed up I ran it all the way to 2,320 RPM. I haven't seen the engine turn that fast and smooth in a year and a half. While I was at WOT I switched off the mag and the engine didn't miss a beat.

Here are some photos of Lynn's trigger assembly mounted on my plane. Compare them with my installation in my previous post, dated April 19.


So, without a doubt, the smaller wheel must be causing me to pick up noise from the crank flange and prop bolts.

That's the good news.

Now, I have to figure out what to do about it. My first inclination is to see if I can find a different sensor and use the existing wheel. I have a lot of $$$ in that trigger wheel, and looking at Lynn's parts, I'm sure he even has far more machining than mine. I know a rep for an industrial sensor company and I'll give him a call tomorrow.

Maybe I could use an aluminum plate, with the embedded magnets, like Klaus uses. I would have to know if that type of Hall Effect device would work with the EC3.



Any other ideas?

Figuring out the Electronic Ignition

Gee, no posts for a month. You'd think I wasn't doing anything. Actually, I've been stymied by the engine. The general symptom has been that I can't get full RPM. Before I started this conversion, I was getting 2,300 static RPM - now I can only get around 2,100, and it's rough.

Yesterday, I finally narrowed it down. The problem is definitely with my electronic ignition, and most likely my installation portion of it.

Yesterday, I ran the engine again, but this time I hooked up an automotive timing light to the #1 spark plug lead and kept the light in the cockpit to closely watch the flash and see what it was telling me. At low RPMs, idle through about 1,500, the flashes were nice and steady - just like when I did the Mode 8 check with the engine off.

However, as I started to raise the throttle, the flashes became intermittent.? It's as plain as day and I don't' know why it took me this long to see it. The faster the engine ran, the worse it got.

When I retarded the throttle, as I came back down to the 1,500 range the flashes on the timing light became nice and smooth again. So, now all I have to figure out, is why this is happening.

I still think there may be trouble in my 6" trigger wheel/sensor installation - possibly picking up noise from the crankshaft flange and prop bolt lugs. Lynn French's engine is down right now and he is kindly lending me his 7" trigger wheel and mount, and they should be here soon. Swapping those parts should quickly confirm or disprove that installation issue.

Air Intake mods - More Sawsall Art

I continue to plug away at programming the EC3 and things are getting better. The mixture plot is getting smoother and the engine is running better.


I have a fifth fuel injector, which is used as a back-up, but it barely ran. I found that it was over-sized, capable of delivering 87 lbs. of fuel/hour and the mixture was extremely rich. This seems to be out of the adjustment range of the EC3 so I ordered a 55 lb./hr. injector. It will be here next week, so in the meantime I am holding off on tuning the engine and will tend to a few other items on the list.

All along, I have been planning a radical change to my combustion air intake. This was successfully accomplished by Harry Hinckley and Greg Zimmerman in Greg's FAST Swearingen SX300. There will be a little scoop in each plenum snout. This air will be directed, through two hard tubes, to the throttle body. Here is a photo of the mock-up I made last year. I have since made the pipes, now I just need to get the scoops placed in the plenum.


As usual, I start with pouring in 2-part foam, held in place with paper dams & tape.


Then I get out my favorite shop tool; Mr. Sawsall:

I use the 14" saw blade to gently remove some of the foam I didn't want.

After rough trimming, I attached a couple of pieces of hard foam, using 2-part foam as glue. The hard foam will make a better foundation for the lip of the scoop. Some wire pins hold the hard foam in place while the 2-part expands.

Since it's cool in the hangar, I'll wait a day before I get into the detail carving.

This may all seem hare-brained, but what the heck. That's what experimental aviation is all about.

More forwards and backwards

The closer I get to the goal, the farther away it gets - at least, sometimes it seems that way.

My current challenge is getting the electronic timing correct, then to program in the mixture "map". To map the mixture settings with the RWS EC3 Electronic Control Unit (ECU), you will input a setting for each 1/2" step of manifold pressure; from idle, all the way to full throttle. You use the fuel/air gauge to determine what the mixture is, at that throttle setting.

This ultimately provides a look-up table for the ECU for any given throttle input.

Before I do that mapping process, I need to get the base ignition timing right. This consists of making a sole timing setting, the "base" timing. In my case, since I am using 9:1 pistons, it will be 25 degrees BTDC, with the engine at full throttle. By simply pushing a button, you use the ECU programming panel to advance or retard the timing.

So that's the theory. The reality of it all becomes more difficult, at least, for me.

First thing is the working conditions. While southern Illinois is hardly the coldest place in the nation, I am getting tired of winter.

I first tie the tail down to a front wheel of my car to keep it from going anywhere. In order to perform the timing, I have to beg a volunteer to come out and run the throttle for me.

In the above photo, (click to see it bigger) you can just see the toothed timing wheel, just aft of the propeller spinner flange. I mark some of the teeth for timing reference. Then I have to hook up a timing light and have the volunteer run it up to full throttle. I lean over the engine and hold the timing light within two inches of the spinning buzz saw. Since it's pretty bright outside I even have to shade the timing marks with my other hand so I can see the strobe flash. I actually kind of rest the side of my hand on the aft end of the spinning prop extension. I'm not sure that OSHA would approve.

I have to wear two jackets, goggles, hearing muffs and a hoodie to keep myself together. I calculated that at 35 degrees and 100 mph of prop blast, the windchill is 14 degrees. But that is really only half the fun. The other, is the sensory kick I get from the combination of the prop blast, the major engine vibration and noise, the snot blowing out of my nose fogging the goggles, and the inherent danger of working around those spinning parts.

So, after repeatedly (10 times?) doing all that, we found a few discrepancies. One, I made the sensor mounting bracket wrong and will have to re-do it. Two, for some unknown reason the engine runs worse when the timing is in the right place. Three, my digital tach bounces around so much I'm not really sure what it is telling me.

So whine, bitch and groan.

But, at least I keep working on it, and I guess that's progress.

Thanks, today, to John Eynon for patiently running the throttle for me.

Closer to the Goal

The recent effort has been directed towards getting the engine to run properly, with the RWS EC3 system. There are all sorts of variables to work through; new throttle body, injectors, homemade induction pipes, the list is long.

Right now, I'm working through getting the mixture and ignition timing properly adjusted. This is a pretty big deal and will take a while.

To complicate things, the readings from the mixture meter have been unreliable. Here is the one I'm using.

It turns out, I mounted the sensor too close to the end of the exhaust pipe. The O2 sensor is very sensitive and I guess that ambient air is getting sucked back into the exhaust pipe, between pulses, particularly at lower RPMs. This winds up showing the mixture to be too lean. As suggested, I clamped on a piece of pipe I had laying around and the mixture meter reading instantly got better.


Again, the use of this meter and sensor is only temporary, until I get everything calibrated.

Right now, I'm running the engine without the canopy installed, which is giving me a real wind-blown hairstyle. The best I have seen, at full throttle is about 2,200 RPM and 29" hg. I have old data that I had attained 2,340 RPM and 29", so I have little way to go.

I'm getting some of the wiring tidied up and pretty soon it will be time to, hook up the rudder cables, install the back-up battery and install the canopy.

On another successful note, my custom designed and built fuel flow circuit board works just great. The Dynon D180 allows you to connect a flow transducer. These transducers typically have a little fan in it, that rotates as fuel flows. A sensor picks up the pulse count and sends it to the D180 and indicates flow in gph. The problem with my system is that fuel passes through an open loop, starting at the header tank, running through pumps and filters, past the fuel injectors, and then back to the header tank. Because of this, any fuel flow transducer will sense ALL the fuel flowing and not just the fuel consumed.

Note: the flow out of the injectors is controlled by the duration of time that the injectors open. More fuel demand - the injector pulse width increases. Less demand - narrower pulse width. The number of pulses per engine revoultion is fixed.

Mike Dwyer to the rescue. Mike is a Dynon dealer and an electronics whiz. Mike designed a circuit that takes a signal from an injector. It converts an increase in pulse width to an increase in pulse frequency. It's all black magic, to me.
I got with Dennis Hannon, the avionics instructor at SIU, and an avionics student, and they fabricated and bench-tested the converter. I named the piece the Dwyer-Hannon Frequency Converter.
And what do you know? I works! Fantastic!


Mike designed in a calibration potentiometer, but the Dynon also has an adjustment multiplier. There is a little formula to dial in the calibration, so in a short while my fuel flow indicator will be correct.

Sweet!

Fowards and Backwards

Good news, bad news, good attitude.

The good news is the engine runs! Having said that, this is all extremely uncharted territory, and if it wasn't for Lynn French, I would be completely in the dark. Lynn is the character that first installed an electronic fuel injection and ignition, in his Tri-Q-200.

I used Bosch 24 lh/hr. fuel injectors, sometimes referred to as "blue tops". These are the same size that Lynn uses and it seemed like a good starting point. The ECU is programmable and you can adjust the fuel flow to your own particular application and injectors. When we first got it started, it was extremely rich. I mean rich, to the point where there was black smoke plainly coming out of the exhaust and now there are two major soot streaks running down the belly.

The first few times I ran it, it was kind of a sensory overload; all these new dials, buttons, and the like, to learn. And, it seemed like some features worked and some didn't. It was, and still is, a lot to sort out.

There is a fair amount of programming of the controller to do. The idea is to first match the basic flow of the injectors to the engine, then to map out the mixture tables.

Adjusting the mixture is interesting. First, instead of a mixture knob that you pull out, there is a mixture dial on the Programming Control Module (PCM). You use the dial for tweaking, but you use the Program Variable, Mode and Store controls to make your adjustments permanent. (Over simplification, really).

To adjust the mixture, you really can't use the conventional EGT. We welded a bung into one of the exhaust stacks and have installed a Bosch automotive oxygen sensor. This is connected to a gauge in the cockpit and it provides a digital presentation if the mixture is rich or lean. This gauge reacts much faster than a regular EGT and is easy to interpret. The first sensor I bought didn't work very well, so I bought a better one which has it's own heater.

The O2 sensor is temporary. They are designed for unleaded fuel and after a while 100LL is said to clog them up. I only need it though, for the initial mixture mapping.

All of this is so new to me and there is so much to learn. Sheesh!

After a while we (C-Rod and I), came to the conclusion that the programming button wasn't working. Now, we may be mistaken, but we think we have it right. Anyway, after lots of diagnostic e-mails, back and forth, with the controller designer/manufacturer, I pulled the unit and am returning it for evaluation.

I will say that the engine starts easily, and seems to run fairly well, considering. There are lots of unknowns here, I have an automotive racing throttle body, homemade induction system and lots of seat-of-the-pants engineering, so I am taking everything in stride.

I guess I'll work on my taxes while I wait the outcome of the controller.

My Red Letter Day

The engine started.

Yes, and I think it's starting to set in. It has been one year, two months, and 15 days since I last flew it, and the engine ran. But, who's counting?

The ice and snow is finally gone, so today C-Rod came out to help and try to fire it up. Hardly anything is safetied or tied down, I just wanted to see if the darned thing would run.


We tied it to my car, looked it all over and hit the button. The prop spun but no start. The EC3 controls both spark and fuel, so after a while I suggested that Charley spray in a little starting ether and see what that did.

I tried it again, and the engine lit and spun up! So, that must have meant the ignition part was working but there was something wrong with the fuel injector part.

We looked and looked, tore some wires fuel injector apart, checked pins, connectors, cables, wiring, all sorts of stuff. Still couldn't get the injectors to fire.


Then I said, "Let's see if maybe it's just the remaining magneto that is working and not the electronic ignition. Charley, spray some more ether and I'll try it with the mag off". It briefly roared and spun over fast as the ether fired up and tried to start.

But, I wondered if the magneto was really turned off. Maybe the mag was working and the ignition was not. "Charley, lets remove the plug wires and try it". So we pulled the Slick's wires, but the engine still tried to start on the ether.

"Charley, just for grins, pull the ALL the plug wires". So he did. To our astonishment, the engine STILL tried to fire up when boosted with the ether! Apparently, the high compression (9:1) pistons caused the either to diesel and ignite.

So, our initial supposition that the ignition must be working, was invalid. We decided to go back to the basics and make sure that the EC3 ECU was getting all the input it needed, and whattya know?

We found two wires reversed. It turns out the main power, from the "A" switch was being sent to the "B" side of the ECU, and vice-versa. Because of this the ECU, wasn't getting fed 12 volts.

I think we would have figured this out four hours earlier, if we weren't led astray by that goofy starting ether. After that was corrected it fired right up!



We ran it for about 15 minutes and seemed to be good. There is still a lot to be done, to be learned, and bugs to be ironed out, but it was a Red Letter Day!

Winter

Went to the hangar today, first time in a week. Too cold to work and enthusiasm was low. There is a ridge of solid ice, about 8" thick, all along the hangar door. If I hit the "OPEN" button, I would destroy the hangar door.

But hooray, tomorrow it's going to be in the 50s and the forecast is way above freezing for at least a week!

Maybe I can get the engine started next week. At least the oil in my new sump hasn't leaked out.

Updated Progress Report

No Engine Start This Month

Winter has dealt an unfortunate blow. Until two days ago, we had a total winter accumulated snowfall of 3/8" and I was gloating about it. However, for the past two days, everything is shut down. The Southern Illinois Airport has been closed for two days. Even the Dairy Queen is closed. M'boro has about two plows and a they are overloaded. We are still waiting for a plow on our street.


I helped the neighbors get free two mornings in a row. Naturally, I got them out with my years of experience living up north. (beats hands on chest).

I doubt I will get to the hangar today, and tomorrow I have to drive to Chicago, to give a presentation on Friday.

Right now, it looks more like an engine on a test stand, than an airframe. I just want to get the thing running, then come the refinements.

So, maybe Tuesday or Wednesday, provided I can get the plane out of the hangar. So here we sit...

The Drum Roll ... Please

My goal was to have an engine start by the end of January.

The fuel injection lines are all hooked up and I checked for leaks. There is now six quarts of oil in the home made oil sump. Spark plugs and wires are installed. There is a propeller on the plane. There is 10 gallons of fresh gas in the plane. All I need to do hook up the wires for the five fuel intectors, and we're ready.

They are predicting, for tomorrow, one of the worst winter storms we've had in years.

Tonight...Snow...sleet and a chance of freezing rain. Snow may be heavy at times. Snow and sleet accumulation of 4 to 6 inches. Ice accumulation of up to one quarter of an inch. Lows in the lower 20s. Northeast winds 10 to 15 mph. Chance of precipitation near 100 percent.

Tuesday...Freezing rain and sleet. Sleet accumulation of 1 to 2 inches. Ice accumulation of up to one quarter of an inch. Highs in the mid 20s. Northeast winds 10 to 15 mph. Chance of precipitation near 100 percent.

Tuesday Night...Snow likely with possible sleet and freezing rain in the evening...then snow likely after midnight. Snow and sleet accumulation of 2 to 4 inches. Total snow accumulation 7 to 10 inches. Total ice accumulation one quarter to one half inch. Lows around 17. North winds 10 to 15 mph. Chance of precipitation 80 percent.

Other than that, it's all good.

Starting to look like an Engine again

I've got the exhaust mounted, ignition coils, the spark plugs, EGT/CHT, and a bunch of other stuff. The wires look bad, but it's really not that bad. UPS brings the last of the fuel fittings on Monday.

A Wife Can Cut to the Chase

At breakfast, I remarked to Sandy that she hadn't produced a painting, suitable for hanging on the wall, since she started taking formal art classes at SIU. She responded, "You haven't flown your plane in a year, either".

It's 18 degrees, here in Murphysboro, and the winds are 16 gusting to 26. Windchill is 3 F.

I hope to have an engine start next week.

Sam the Plumber

Cold weather continues to hamper progress. Last week it was 19 degrees F and the hangar was probably 23F.

To me, this electronic fuel injection is a big deal to install, but very interesting. Right now, I still don't have have all the plumping fittings that I need.

It seems like I always have the wrong ones. I recently sat down and ordered everything I thought I'd need. I used a couple of sources, Summit Racing and Ebay. When everything arrived I found a major screw-up. I ordered -6 fittings, instead of -4. Rats! You ever try and return anything through Ebay?

Yesterday, I found that even the different brands aren't always compatible. I had accumulated Earls's fittings, Summit Racing's own brand and Aeroquip. I find that the Earl's fittings don't like the Aeroquip braided hose. From here on out I will try to use the Aeroquip, but man, they are proud of their stuff! Expensive!

The fuel system is a closed loop. Here is the path:

From the header tank
through the shutoff valve
through the 40 micron gascolator
through the fuel pump
through the 10 micron filter
through the left firewall
past five fuel injectors
returned through the right firewall
through the fuel pressure regulator and
back into the header tank.

There are probably 30 joints where fuel can leak, this part is a challenge.

Speaking of fuel injection, through a rotary engine news group, I came across a link on rolling your own fuel injection controller, from Paul Lamar. While it may look promising, it apparently hasn't been built yet. There is also some information about Klaus Savier's fuel injection system.

Throttle connections

It's kind of hard to see in these photos (click on'em to see them bigger) , but more progress is happening. A new throttle cable is installed and attached to a sideways mounted, Jenvey racing throttle body. Each intake tube gets a fuel injector and the throttle body has a fifth one for an emergency get-home device.

The end of the throttle cable housing has to be securely secured, which was yet another problem for this installation. I wound up embedding a couple of Clickbond studs on the side of the carbon fiber oil sump and attached a bracket to hold the throttle. The photos aren't the greatest, but I'll get more when things move on a little.



You can see the fittings for the fuel injectors, along with the obligatory duct tape. Since the fuel will be pressurized at 42 psi, it's imperative that nothing leaks - so I'm spending a lot of time cogitating on the matter and searching for fuel proof duct tape.


Photo of the right side of the oil sump, showing the attached throttle and sump support brackets.


The goal is to fire up the engine started by the end of the month on January 2009.

Year-end Update

Off topic, from the '70s. Here's an old photo of me and my buddies making a practice jump at East Troy, Wisconsin. We were getting ready for regional 10-man speed star competition.


It was a good year, but I do regret not getting to fly and race this thing.

Having said that, I am really getting close. I'm working on firewall forward and things aren't too bad. I just had two days of working with the hangar door open and it is really a morale booster. So much better than trying to think and fabricate in a dungeon.

My most recent success (meaning overcome obstacle) is mounting my ignition coils. With the RWS EC3 injection/ignition system, each plug gets it's own LS1 coil. I understand these coils are used on Corvette engines. I took a cue from Lynn French's creative installation and mounted two of them directly on the engine mount. I think this will work pretty well.




My short-term goal is to fire up the engine by the end of January.

I don't work in a total vacuum and certainly don't have the skills to do it all myself. Here are just some of the people that helped me this past year. I know I don't have everyone and if you don't see yourself here, please don't be offended. I probably lost those brain cells connected with your name.

Billy Cheek
Bob Knuckolls and the AeroElectric Connection e-mail list
Bruce Dallas
Charley "C-Rod" Rodriguez
Cory Steinkoneig
David Posey
Dennis Hannon
Don Bartlett
Grither's Auto Body
Harry Hinckley
Jerry Marstall
John Cotter
John Eynon
Ken Robinson
Larry Dauer
Keven Mitchell
Lynn French
Mike Bergen
Mike Burgener
Mike Dwyer
Mike Most
Rob Hoskins
Various SIU Aviation Technology students

And the award for the most help and patient understanding goes to:

My beautiful wife, Sandy

My original target date, for project completion, was May 1, 2008. I still think that was realistic for the original project list, but I kept adding things and it grew and grew and grew. Not on the original list were; replacement of the rear wing, new canopy, and TWO PAINT JOBS.

I just need to stay at it.

Composite Oil Sump is 99.4% Complete

Don't try this at home!

There were just a few things to attend to for the oil sump; like installing a filler cap and post curing the thing. You can refer back to this post to see how I got it this far. http://samhoskins.blogspot.com/2008/06/carbon-fiber-oil-sump.html

I was able to get into the composites lab at SIU AvTech to make the final parts. I used an AN825-20D cap and an AN824-20D nut as the final fitting. I intend to insert a 1/8" welding rod as the dipstick. Thanks to Justin Mace for that idea.

After the thing was complete, I used an oven at SIU to post cure it. This particular epoxy remains quite brittle until the crosslink reaction is complete. I kept it at 140 degrees for 10 hours, then ramped it up to 300 degrees for about 20 minutes. This oven has a precise thermostat and a circulating fan. As you can see, it just barely fit!

After I fabricate the dipstick I'll have to shorten the oil sump suction tube. Then it'll be time to bolt it up and add oil!

I sure hope it doesn't leak.

Today's report

Just a quick update. I'm working on the firewall forward stuff now. The bigger challenges here are to install the trigger sensor, the four LS1 ignition coils, complete earlier work on the carbon fiber oil sump, and install the new Jenvy throttle body and linkage.

As usual, the biggest hurdle is just starting. I had been fretting about it a lot, but I found once I got started on the trigger sensors bracket that it was no big deal. Using a free CAD program, I laid out the drawing. Then it was just a lot of cutting, drilling and fitting.

My main tools are a band saw, drill press and a vice. No mill or lathe, unfortunately. Here's a couple of photos of the trigger sensor. Click on the photos to see 'em bigger.