Electroair EIS installed

[kevinw]

Any updates?

So far so good. Ease of starting is definitely a plus. To sum it up I've been happy with a slight increase in cruise speed in the airplane and I've also noticed it climbs better. I've noticed I'm getting up to 7,000 faster than I was before, or at least it sure seem that way. The one thing I was hoping for and not seeing is a change in fuel burn. I still haven't flown it at 10-11K where most claim that benefit happens. As I mentioned in a previous post my airplane has been in the avionics shop for a panel upgrade and it took longer than expected due to an autopilot part that I needed so I haven't had it back very long. I'll be going on some longer trips and when I do I'll report back. I will say I've had no issues with it since it's been installed. It did have a defective wiring harness that had to be replaced but that was discovered and replaced before it left the shop. The mechanic did a great job and mine was his first. If you're considering installing one of these I would recommend having a second red master rocker switch installed. In the pic it's labeled EIS. It makes for a clean look; I've since replaced the white tape with red. Also note that the unit comes from the factory pre-set with base timing of 25 degrees BTDC. My mechanic had to send it back to electorair to have this adjusted to 20 degrees for my engine. If I knew this ahead of time I could have ordered it this way but I bought mine from AS because it was about $400 less expensive. I know there are mixed feeling about electronic ignition but I've been happy with mine and have no regrets whatsoever.

[cujet]

 What I would like to know is how it makes 200 HP at 25 degrees, but when you put two mags on the accessory case, then reset the timing to 20 degrees the power is the same.  

 

The Lycoming angle valve 200HP engines never, ever made 200HP @ 2700 RPM. The very best examples made 193-195HP, at 25 degrees timing, on a cool day, corrected for STP (standard temp and pressure) The reason for this was simply the certification rules of the time allowed for some HP discrepancy. Lycoming took advantage of this. 

 

In fact, many Lycoming 360 angle valve engines at 20 degrees produce 187-189 HP in real world testing. And, that's with an open throttle body inlet, and equal length dyno header. As installed in many aircraft, it's even lower. 

 

Just an FYI, the IO390 makes 210HP, 15 more than the 360 in "fighting form". 

[NotarPilot]

On 3/24/2015 at 8:06 PM, cujet said:

Just an FYI, the IO390 makes 210HP, 15 more than the 360 in "fighting form". 

And at one hell of a premium too.

[Mcstealth]

On March 24, 2015 at 0:21 PM, kevinw said:

So far so good. Ease of starting is definitely a plus. To sum it up I've been happy with a slight increase in cruise speed in the airplane and I've also noticed it climbs better. I've noticed I'm getting up to 7,000 faster than I was before, or at least it sure seem that way. The one thing I was hoping for and not seeing is a change in fuel burn. I still haven't flown it at 10-11K where most claim that benefit happens. As I mentioned in a previous post my airplane has been in the avionics shop for a panel upgrade and it took longer than expected due to an autopilot part that I needed so I haven't had it back very long. I'll be going on some longer trips and when I do I'll report back. I will say I've had no issues with it since it's been installed. It did have a defective wiring harness that had to be replaced but that was discovered and replaced before it left the shop. The mechanic did a great job and mine was his first. If you're considering installing one of these I would recommend having a second red master rocker switch installed. In the pic it's labeled EIS. It makes for a clean look; I've since replaced the white tape with red. Also note that the unit comes from the factory pre-set with base timing of 25 degrees BTDC. My mechanic had to send it back to electorair to have this adjusted to 20 degrees for my engine. If I knew this ahead of time I could have ordered it this way but I bought mine from AS because it was about $400 less expensive. I know there are mixed feeling about electronic ignition but I've been happy with mine and have no regrets whatsoever.

So in the long run, happy?

[jetdriven]

On 3/24/2015 at 10:06 PM, cujet said:

 

The Lycoming angle valve 200HP engines never, ever made 200HP @ 2700 RPM. The very best examples made 193-195HP, at 25 degrees timing, on a cool day, corrected for STP (standard temp and pressure) The reason for this was simply the certification rules of the time allowed for some HP discrepancy. Lycoming took advantage of this. 

 

In fact, many Lycoming 360 angle valve engines at 20 degrees produce 187-189 HP in real world testing. And, that's with an open throttle body inlet, and equal length dyno header. As installed in many aircraft, it's even lower. 

 

Just an FYI, the IO390 makes 210HP, 15 more than the 360 in "fighting form". 

So, 8-10 horsepower less at 20 degrees than 25, I can buy that.  Its certainly noticeable, and easy to measure. It especially shows up when you try to run it LOP, the 20 degree configuration loses 3 knots or so at peak, and another 3-5 just LOP. the 25 degree setup will perform much better LOP.  You only lose 3 knots at 15 LOP. As the flame front slows down when yo go leaner, the extra 5 degrees of timing makes all the difference.

[kevinw]

1 minute ago, Mcstealth said:

So in the long run, happy?

I really am. I can't say it's night and day different from the original set up but it certainly runs smoother so I wouldn't go back. The only issue I had was with radio interference. Took forever to pinpoint but it turns out the EIS plug wires must be separated with about 2" of hose and zip ties. Other than that I recommend the fine wire plugs that are now available with the system. I had them installed a few months ago and the engine starts effortlessly now. Not that it was big problem but it cranked a little longer than I liked. Then new plugs changed that. Plus I notice they don't load up like the massives but I still aggressively lean on the ground out of habit.

[NotarPilot]

For those of you interested in an EIS with a dual mag engine like me, I called EIS the other day and was told they are working on a dual mag solution and although it hasn't flown yet they hope to have it STC'd by next Airventure "If everything goes well." Sounds like a very optimistic timeframe to me but at least they're working on it.

[ArtVandelay]

Have you noticed any changes to EGTs or CHTs?
If your timing went from 25 to 20, what changes would one expect in the EGTs?

[carusoam]

CHTs go up predictably with 25° BTDC timing.... as the increased percentage of fuel is burned before the exhaust valve can open...

EGTs would trend lower as less fuel would be able to burn after the exhaust valve opens.

Second hand observation of Byron's work...

Best regards,

-a-

[ArtVandelay]

CHTs go up predictably with 25° BTDC timing.... as the increased percentage of fuel is burned before the exhaust valve can open...
EGTs would trend lower as less fuel would be able to burn after the exhaust valve opens.
Second hand observation of Byron's work...
Best regards,
-a-

But if you run LOP, whether you're 20 or 25 would not all the fuel be burned because of the excess of oxygen? Its just effects went burn is complete, so timing should be dependent on the RPM.

I just had my magnetos serviced and my EGTs are higher across all cylinders and wondering if that's a good thing or bad thing?

[gsxrpilot]

Advancing the timing from 20 to 25 BTDC increases the CHT's across the board because of greatly increased internal cylinder pressure. The increased peak pressure decreases the insulating boundary layer against the cylinder walls. This allows more of the heat to be transferred to the cylinder instead of flushing the heat down the exhaust. The decreased EGT is because of the extra expansion of the gasses after combustion. The temperature of gas cools in direct relation to it's expansion. More expansion equals more cooling and lower EGT.

Running LOP just moves the effective timing back to give you the peak pressure and corresponding CHT/EGT of a normally timed engine at 20 BTDC.  

Since the two worst enemies of metal and my cylinders are pressure and heat, I'll keep my magnetos timed correctly and then run LOP to reduce CHT and internal peak pressure even further.

We watched this happen on the test stand in Ada, OK. Advancing the timing, exponentially increases internal peak pressure from a normal 700 psi, well into the thousands of psi.  Running LOP effectively retards the timing which lowers the peak pressure as low as 400 psi and lowers CHT's correspondingly. This is much nicer for my cylinders.

Finally, variable timing on an aircraft engine isn't as useful as it is on other engines since we can control the mixture. The same effect of moving the timing around can be had by adjusting the mixture through the range from full rich to max lean

Just my recently APS educated $0.02

[aaronk25]

A mechanic set my mags in the J to 20d and the plane lost 5kts and egt went up 30 or so.

Like jetdriven said, the 25d timing set up really helps the plane run LOP. My plane was a dog LOP at 20d. Rate of climb was reduced too, runway rollout etc.




Sent from my iPhone using Tapatalk

[carusoam]

ICP sensors would be nice.

Their current cost is probably higher than a new cylinder.

Best regards,

-a-

[gsxrpilot]

GAMI said if they could get the cost down to something that even a few would pay, they'd make them available. It was interesting to see spark plugs with the barrel off set so that a very thin hole can be drilled through the housing into the cylinder and the pressure transducer threaded into the hole.

[Ragsf15e]

I fly a C172 with eis at work often, and it sure does start nice, run smooth, and it seems faster, but I haven't done any measurement for that.  I like it so much, I was starting to think about eis on the Mooney, but the last thing I want to do is something that might shorten the life of my engine by increasing temps/pressures beyond reason.  Typically I fly around 8-10,000, 60-70% power at peak or slightly lean of peak.  She runs smoothly deep lop, but I find significant loss of speed as I go lop.  The cht temps are always below 350 in cruise. Its well instrumented with JPI 930.

Stupid questions that I don't have time to figure out right now... what timing is my io-360 a1a on the 1968 M20F supposed to have? 20 or 25 btdc?  

Does the eis change this timing at wot cruise or just during start and low power operations to keep it smooth?

Edited October 29, 2016 by Ragsf15e

[carusoam]

1) This is Ross' favorite topic...

2) going LOP is a nice way to keep the CHTs down and the EGTs down.  The side effect (in an NA engine) is it keeps the power down as well.

3) by adding additional air molecules into the mix, the chemical reaction is getting slowed down somewhat. (Compared to peak)  statistically speaking a fuel molecule has to run into an oxygen molecule with the heat of ignition being available.  Changing to a rich air environment air molecules will crash into other air molecules and nothing happens on a percentage basis...

4) technically we aren't adding air, we are removing fuel flow (mixture control)

5) removing fuel will slow you down, no matter how improved the burn efficiency gets.

6) at 10k' running just lean of LOP is efficient, and doesn't leave very much power out.  

7) The O will cruise 175 ROP and 165 near peak LOP.  The savings is about 2gph.... (round numbers)

8) Without reliable ICP data, it is difficult to run at peak without safely avoiding the red box.  (At lower altitudes)

9) Climbing ROP is 200-300°F.  Climbing LOP (for me), has been left for another day...

10) a five degree change in timing would be less effective during LOP, because the flame is mostly being completed before the exhaust valve opens.  At least compared to a high powered ROP event where flames are exiting the cylinder a few inches long...

pp thoughts that have been read here on MS.

Best regards,

-a-

[jetdriven]

ALL IO-360 engines are 25 degrees of timing, with optional timing of 20 degrees for engines without the Bendix dual magneto. It's just that, optional.  If the engine log shows the SI complied with, you can un-do it. The factory likes to say how it doesn't matter, it's safer, etc but the TCDS still says 25. 

Edited October 30, 2016 by jetdriven

[Ron McBride]

Byron

I have a IO360 C1C out of a Piper in my Mooney, that has been changed to a A1A.  The engine data plate calls for 20* of advance on it.  Most A&P's that see this plate want to  time the engine at 20*,  they say that they have to, because of the engine data plate.  Some will time the mags at 25*, but I have to ask every time.

What is correct.

Ron

[jetdriven]

Read the lycoming SI 1325a. Put the proper p/n left magneto on, and stamp a 5 over the 0 on the data plate.  Make a log entry you un-incorporated lycoming SI 1325a. Timing is now 25 degrees per the 1E10 TCDS. 

[bradp]

Do the full SI or don't.  I may be preaching to the pulpit but moving the timing away from the data plate if the mags are impulse coupled can result in kick back.  That's why you need the 25-deg impulse coupled mag.  Also the reason why most mechanics will only set the timing to what's stamped  :-)

[kevinw]

I called Electroair tech support about my controller being reprogrammed from 25 to 20. I don't want to be giving up speed or hp. He advised me not to change it. He said the timing will start advancing when the MP starts dropping below 24". It can advance as much as 12-13 degrees totaling as much as 33 degrees. If I have it reprogrammed to 25d the timing will advance linearly and that means as much as 38d. He said that's too much. I'm far from an expert, just relaying the info I received on Monday. I'm not completely sold on this and if I can pick up the extra power and speed without compromising the cylinders, I'm interested in learning more but he said I have the right setup.


Sent from my iPhone using Tapatalk

[jetdriven]

9 minutes ago, kevinw said:

I called Electroair tech support about my controller being reprogrammed from 25 to 20. I don't want to be giving up speed or hp. He advised me not to change it. He said the timing will start advancing when the MP starts dropping below 24". It can advance as much as 12-13 degrees totaling as much as 33 degrees. If I have it reprogrammed to 25d the timing will advance linearly and that means as much as 38d. He said that's too much. I'm far from an expert, just relaying the info I received on Monday. I'm not completely sold on this and if I can pick up the extra power and speed without compromising the cylinders, I'm interested in learning more but he said I have the right setup.


Sent from my iPhone using Tapatalk

It's too much for an IO-360 A3B6 with 20 on the data plate but not too much for a A1A with 25 on the data plate.  Makes perfect sense 

[gsxrpilot]

15 hours ago, kevinw said:

I called Electroair tech support about my controller being reprogrammed from 25 to 20. I don't want to be giving up speed or hp. He advised me not to change it. He said the timing will start advancing when the MP starts dropping below 24". It can advance as much as 12-13 degrees totaling as much as 33 degrees. If I have it reprogrammed to 25d the timing will advance linearly and that means as much as 38d. 

Certainly below 24" of MP is relatively low power, which helps. But seeing what 30 degrees advance, looked like on the test stand in Ada, I don't want my engine anywhere near that. 

Just my $0.02

[kevinw]

Just now, gsxrpilot said:

Certainly below 24" of MP is relatively low power, which helps. But seeing what 30 degrees advance, looked like on the test stand in Ada, I don't want my engine anywhere near that. 

Just my $0.02

I would like to know more about this after reading some of your posts. My understanding is the timing will advance little by little as altitude increases and MP drops. That said, at 7-9K MSL, what seems to be the sweet spot for the IO-360, I don't think is advancing much. I took is as the most it could advance was 12-13 degrees if I was at altitudes I would normally never be at, 15K+. I could be wrong and will look into it further.

By the way, I've read good things about the Advanced Pilot Seminar. I've thought about buying the online course. -Kevin

[jetdriven]

it's not a very smart box. It advanced timing based on manifold pressure. you don't get the full timing advance unless below like 17" of MP and above 24" it's base timing.  I posted the timing graph on here before.