EA81 duel ign.

[chook]

Tony - dual ignition - extra weight and more things to go wrong.
With normal maintenance and good pre flights when was the last time we had an ignition failure with an ea81?
I would like electronic ignition purely because the points eventually wear.
Currently my EA81 spark plugs are running very white so I am in the process of going up one level of richness in my Weber and using the next colder plugs (BPR7ES) in lieu of the B6ES series.

Regards..........Chook

[mad max]

Over the years I've had one original subaru senser/igniter fail while pre-rotating. (Blamed the low voltage and starter motor reverse current spikes) solved problem by fitting a diode at the elect. pre-rotator. And I've had two sets of points brake springs. Since installing twin electronic ign. into single plugs it started better and never failed. Aircraft now happily lives at Byron Bay.

[chook]

Tony sorry about the delay....
I was reviewing my G133 notes and stumbled across this for you -

Subaru dual electronic ignition notes from Recreational Flying forum.

Paul if you go to the Yahoo group 'flysoob' in the attachment section there is a full drawing and details of how to made your own base plate to accept 2 trigger modules therefor giving you dual ignition .
this drives 2 coils that goes to a coil joiner (large diode block) by mallory or msd that has one lead from it to your stock dissy cap.
I have this set up on my suby ea81 and it works great . the trigger moduals are from local popular cars (pajeros and hyundia i think) and have an after market part number making them available though your local repco,autopro etc.


The module is P/N BIM076 from repco and the distributor you will need for the reluctor is from a mitsubishi pajero '83 to '93 or mitsubishi nimbus '84 to '92 .
i swapped out the with points cam assembly with the mitsubishi assemble and just had to make a little spacer or some thing. My suggestion would be to set up your mechanical advance to have 6 deg of movement (distributor that is not crank) . your can do this yourself with a degree wheel or find an auto elect shop that still has a distributor graph and knows how to use it.
then when back in the engine rev to say 4000rpm and set your timing to 28 deg (absolutely no more ) and this will give you an idle advance of 16 deg which will be smooth and wont kick back on the starter when cranking.
There has been a lot of experts write all sorts of timing requirements for these motors and I can tell you from my own experience (4 months playing on my own dyno)that they don't make any more power with more than 28deg regardless of compression ratio or camshaft.
the coil joiners can be bought though performance wholesale, rocket ind or someone like that.
good luck with all this if you need more info I'm happy to help

cheers

Jim
JimG, Jan 9, 2011

Gooday Paul
I've flown my EA81 on points, the Hitachi electronic distributor as fitted to Australian delivered cars from about 1984 onwards (this is the one with the integral magnet that Maj speaks of), and in my opinion the best of all is the Nippon Denso electronic distributor that came with Japanese import replacement engines. The big advantage is that the electronic module can be taken out of the distributor and mounted on a heat sink on the firewall, leaving only the reluctor coil in the distributor. This minimizes the most likely cause of failure of the electronic module - engine heat cycles. My 1990 Suzuki Sierra has the same internals as the Subaru distributor, so parts should be readily available if ever needed. I also recall that Ford Lasers used the same ND electronics. It feeds a Bosch GT transformer style coil with ballast resistor and then platinum tipped plugs. I have done several hundred hours on Avgas with this setup, and no issues so far.
bushcaddy105, Jan 10, 2011

With acknowledgement to Recreational flyer and their content.

Regards...........Chook.

[tonydenton]

hello chook , yes agree with you on the lack of having any failures with dizzy and spark plugs, I was wanting the dual spark solely because it was in the SUB 4 HEADS.[ I WANT THE HEADS FOR THE POWER only]. or for me to loose 10 or 12 kg's and stay the way it is . I have taken the auto flight box off and gone back to the rotax C box so I'm saving weight there . the exhaust be going next for something lighter soon.

[RossM]

this is from yahoo FLYSOOB
https://groups.yahoo.com/neo/groups/FlySoob/files


attached is a photo and a word document.
not sure if I can attach the 'How to instruction' sheet, file is a bit big.

[RossM]

Cannot save it even if saved as a zip file, as too big
in the FLYSOOB site, under files, a pdf called _DualIgnitionConversion.pdf

[RossM]

see if this works

[chook]

Much better thanks Ross.
Regards.......Chook