Interested parties and George (GAMI),

 

This document was prepared as my promise to provide some data about the operation of the Unison LASAR ignition system installed on my Lyc IO 320.

 

George and I have gone round and round about lower EGT temps, timing, performance, etc.  So, let me start out this way.

 

1. I installed the LASAR system on a Lyc IO 320 engine several years ago.  Before LASAR (and with regular Slick mags) that engine typically ran EGT peaks at 1490F to 1500F. 

 

Remember all thru this discussion that my engine monitor was and still is a Vision Microsystems EPI 800 – that means that temperature measurements are processed in 8F degree increments with the display in increments of 10F degrees.  There is no way to record any of the data except by hand.  Also note that I must twist a display switch to see temps cyl by cyl.  Another constant is that the engine is fed unfiltered air through an efficient ram air system.

 

2. After the LASAR system was installed I experienced lively takeoff runs, improved Midwest climb performance and an apparent improvement in cruise performance.  I have no old data to back this up but I do remember that peak EGTs were generally in the range of 1420F-1430F. Period.  That is a drop of 60F to 80F degrees, just as LASAR documentation claimed.  Furthermore, CHTs were 10F-20F higher on a 400 hour Cermichome Cyl engine.  At that time I did not have a switch to shut off the LASAR (switch to LASAR mags only).  Also, remember that I always ran that engine ROP.

 

3. The LASAR system was installed because of the performance promise and the simple dual mag backup.

 

4. As the consequence of circumstances 1.5 years ago (don’t ask), the engine was rebuilt with new one piece cams, new heavier crank, ECI Titan Cermi-nil cylinders and new (interesting) Hartzell CS 70” prop blades were mounted.  During the “experimental” time other changes were installed such as .022 diameter shrouded injectors fed by a ram air pitot to better match the cruise atomization air pressure to the MAP.  This engine is not the same as the old one even though both utilized 9:1 pistons and the 12 lb harmonic damper. 

 

5. I did not experience the same performance as the prior engine after the installation was “cleaned up” to my standards (don’t ask).  I installed a switch to go between the LASAR electronic system (EI) and the LASAR mags.  NOTE:  The “mags” distribute the spark regardless of the source – keep this in mind.  In flight tests, the mags provided better performance than the EI.  Puzzled, I contacted Unison.  They provided new mags because the function of detecting system failure and automatically switching to the backup mags was activated by a switch in the bulge in the mag pigtail cable.  This switch had failed in a way that had LASAR operation activating both functions (EI and Mag) at the same time with a reduction in performance as compared to mag only.  Thus my experience.

 

6. New LASAR mags were installed and tests were performed that demonstrated more lively takeoff and climb but were confusing on cruise/race performance.  NOTE: Unison lawyers have determined that LASAR timing information is proprietary.  But, I know this – timing is advanced below 85% power or 24 (26?) inches of MAP (I think).

 

7. Unsatisfactory test results betwixt mag (that’s LASAR mag) and EI led to a fruitless test (couldn’t get the Unison engineering computer to report on anything).  NOTE: First “sensor” mag from Unison could not be timed better than 29-30 degrees BTDC – just slightly outside their acceptable range of 3 degrees. Hmmpf!

 

8. Replaced sensor (left) mag with a new one that could be timed within specs – but was still 27 degrees BTDC, not the 25 degrees called out for the engine.

 

9. Then, I was supplied with an additional two controller boxes that operate thusly:

 

1. The Original – engineered for an O 320 – aggressive timing advance.
2. An IO 360 box – medium aggressive timing.
3. An O 360 box  – less aggressive timing advance.

 

10. Most recent data from flights with the O-360 box as follows:

 

Three Climb-out tests showed indistinguishable differences between LASAR and LASAR mags – However, the data can be used as a base point.  Note that it is a little difficult to remember/record data during this busy time.

 

Takeoff (700 MSL) and climb at 130 IAS.  Starting Baro 30.14, OAT 14C, PALT 510, Dalt 740:

RPM 2690, MAP 29.6, FF 15.4 gph. Monitoring only Cyl 4 (usual first to lean) EGT started at 1280F and advanced to 1310F thru the climb until it drops back to about 1280F, approximately 4000 MSL, when leaning begins to maintain EGTs at 1300-1310.

 

At 8500 MSL

 

Palt 8410, Dalt 8480, Baro 30.14, OAT 3C, TAT -2C, IAS 176, TAS 198

WOT, RPM 2510, MAP 23.3

*** LASAR active ***

#4 peak @ 1420, FF 8.2,  50F LOP 1370 @ FF 7.6 gph, IAS 176, TAS 198

  CHT    EGT

1 330  1360

2 350  1350

3 350  1360

4 350  1370

 

Mixture changed to 100F ROP:

 

IAS 177 TAS 198 FF 9.5 gph

   CHT   EGT

1 360  1300

2 360  1290

3 360  1280

4 360  1320

 

LASAR turned off – I.E. switch to LASAR mags only

The FF increased to 9.8-9.9 gph.

 

#4 peak at 1430, FF 8 gph, 50F LOP 1380 @ FF 7.5-7.6 gph, IAS 170-172, TAS 194

   CHT  EGT

1 320  1380

2 340  1380

3 340  1380

4 340  1380

 

Mixture changed to 100F ROP

 

IAS 177, TAS 198, FF 9.5 gph

  CHT  EGT

1 340  1330

2 340  1300

3 340  1300

4 340  1330

 

Recently, I changed back to the O-320 controller.  Climb out information seemed as before.

 

At 8500 MSL

 

Palt 8500, Dalt 8460, OAT 2C, Baro 29.99, Occasional turbulence, leaned to about 100F ROP

WOT, MAP 23”, RPM 2490, FF 9.1, LASAR ON

IAS 174, TAS 195

  CHT  EGT

1 370  err

2 370  1290

3 370  1290

4 380 1320

 

Yes, the EGT probe or connection for cyl#1 failed on this flight.

 

LASAR OFF – Only LASAR mags operating, no mixture adjustment:

IAS 172, TAS 193, FF 9.2

  CHT  EGT

1 360  err

2 350  1310

3 350  1300

4 360  1330

 

I gave up because of some turbulence at this altitude.

 

OBSERVATIONS:

1^st Run

        LASAR ON  MAGS ONLY

LOP  IAS 176      IAS 172

ROP  IAS 177      IAS 177

 

        LASAR ON  MAGS ONLY

LOP  FF 8.2         FF 8.0

ROP  FF 9.5         FF 9.5

 

Hmmmmm…..

 

With the rotten weather and a vacation, I have not performed any more tests.

 

Fore those interested, I have included some text and URLs to other engine management systems for your perusal:

 

Light Speed electronic ignition:

 

http://www.lsecorp.com/Products/DualSystems.htm

 

 

The benefits of installing a dual electronic ignition system are numerous.  Pilots frequently asked questions regarding the benefits and specifications of dual PLASMA CDI are outlined below. 

-An additional 5% gain in fuel efficiency. 
When running at sea level and 2,500 rpm, a single PLASMA CDI will yield approximately 10% gain in fuel efficiency.   A dual PLASMA CDI system will generate approximately 15% gain in fuel efficiency when run at the same settings.  As altitude increases, fuel burn decreases and the benefits of installing a dual ignition system become more and more significant.

-An additional 2% gain in horsepower.
When running at sea level and 2,500 rpm, a single PLASMA CDI will generally produce 4% more horsepower than a mag.  A dual PLASMA CDI installation will produce approximately 6% more horsepower compared to two magnetos.

-Increased engine smoothness.
When a second ignition system is installed, engine smoothness is noticeably improved.

*

 

http://www.gami.com/frames.htm

 

 

GAMI's Electronic Ignition, PRISM™

PRISM™
(Pressure Reactive Intelligent Spark Management)

Features:
•Optimized Spark Timing to achieve maximum brake torque

•Simple, fewer moving parts, fiber optic design

•Increased horsepower at all power settings

•Smoother engine operation- reduces coefficient of variation of combustion- even on lean mixtures

•More efficient engine operation-CDI produces larger spark at optimized time BTDC

•Replaces both magnetos- no overhaul required prior to TBO

•Fully redundant design- proven electronic durability with quad redundant ignition

•Includes GAMI's Supplenator™ Supplemental Alternator- back-up power to primary alternator and battery and GAMI's PDU™ Panel Display Unit

•Automatic detection/prevention of detonation

•Maintains lower peak cylinder pressures- reduced loads on power train components, longer engine life

•Allows for the future use of lower octane, unleaded fuels. This is the only system on the millennial horizon that is inherently compatible with lower octane, unleaded fuels.

•Champion® ignition components (spark plugs, wires, coils)

•Optional panel display of actual real-time horsepower and torque

•Optional digital tachometer

•Optional extensive on-board engine diagnostic capability

•Improved fuel economy- lower BSFCs than previously possible

•Significantly lower EGTs/TITs for reduced exhaust system maintenance

FAA STC certification expected soon!

 

 

http://www.unisonindustries.com/products/lasar_installation/lasar_inst_menu.html

 

http://www.unisonindustries.com/pdf/marketing_literature/LASAR%20320%20Series%20Engines.pdf

 

http://www.unisonindustries.com/pdf/marketing_literature/L1512C.PDF