zenith 701

Gooday MikeSome time ago I posted the full specs of my engine - search "Subaru EA81" and it should come up. I use a stock manifold from an EA82 with a home-made adaptor elbow to mount an SU HIF6 carby as used on Volvo B series engines back in about the 1970's or 80's. It's 1 3/4 inch throat and feeds the EA81 very well.

The reluctor is just a permanent magnet with a coil wound around it. The rotor has pole pieces rotating in this magnetic field which cause changes in the field, and therefore a voltage spike is created each time a pole piece passes the reluctor. This voltage triggers an electronic switch (the so-called "module") which switches the primary current in the ignition coil. There is no mechanical contact - hence nothing to wear as compared to points. There are 2 wires from the reluctor to the trigger module. The trigger module has 2 wires to the coil primary, the positive one also is fed with 12 volts from the ignition switch. That's it.

KISS - "Keep it simple, Stupid" or words to that effect. I have tried to maintain as many as possible of the systems the EA81 operated under when in a car, e.g. cooling (still using standard thermostat and water pump), ignition, crankcase ventilation. I also don't use an oil cooler, just provide airflow over the stock sump. I do, however, use a larger single carby to provide sufficient airflow at the revs required.

Gooday PaulI'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.

Sorry to throw cold water on the use of waste spark ignition on carby EA81's.I went down this path right from day 1 with my EA81 and it took me a while to work out why it would miss fire above about 3500 rpm. Eventual answer? With the reworked cam profile, and the Siamesed inlet ports, the wasted spark occurs just BEFORE the relevant inlet valve fully closes. (Check the valve overlap degrees). This allows the apparently irrelevant spark to fire stray mixture in the inlet manifold, probably due to resonance effects at certain RPM. Hence my previously posted path of points distributor, Hitachi electronic dizzy to Nippon Denso electronic dizzy. If you want my flywheel triggered waste spark setup to further experiment with, you are welcome to it. (It even includes a retard programme for starting). I keep coming back to the KISS principle for engine setups!

Mike, Consider using waste spark system getting rid of the dizzy,with all of it's mechanical slop et al.The system is easily set up with the EDIS system from donor FORD motors. Controlled by the AutoSport Lab

Microcontrooler called MegaJolt Lite. Completely mapable ignition withh several configurable output ports.

 

Can use either MAP or TPS inputs. ROCK solid ignition......BIG rock! Needs a 36-1 tooth trigger wheel mounted

 

on the crank and reluctor sensor.

Geeeeez Zenith,. . . . .that's nearly the shortest forum post I've seen for a few weeks ! !Welcome to the forum,. . . . . Wot part of Illinois is it that you fly from ? . . .

 

Phil

Hi zenith701, I am setting up an electronic fuel injection system for this engine and was going to use a crank triggered CDI ignition with individual coil packs for each cylinder. The ECU I am using is a Haltec 3d fuel only. The project has stalled at the moment due to time constraints, however I'm well under way with having had made a set of Mahle forged Pistons and found a pair of twin port heads. Cheers, Ray.

Gooday PaulI'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.

Subaru cars are an arm of Fuji Heavy industries who also build planes and the divisions have nothing to do with each other.Subaru's first horizontally opposed engine was a 1000cc aimed at the competitive 1000cc car class in Japan at the time (mid '60's) - with a whopping 50hp and nothing to do with planes other than Fuji had good insight into the layouts of Continentals and Lycomings which they used in their planes - and none of them less than 250hp. That experience, and VW of course, may have swayed them to go with the flat 4 design.

 

It is a car engine and always was a car engine - a bloody reliable one at that though having rebuilt a couple of them and importing them for 15 years. In fact in my entire mechanical and workshop career, I can't remember a 1400, 1600 or 1800 ever coming in with major failure of any kind other than extreme mileage simply needing rings and bearings. Get a shock the first time you see how narrow the big ends on them are too, nothing else comes close.

 

I own an EA81 with redrive in an airplane so yell if you need some pictures of the setup.

Subaru EA81Hi there. I to have decided to power my future kit aircraft with the Subaru EA81 engine after much research and indecision over the power plant. Like others on this forum,I looked at the Rotax 912uls 100hp. Great engine, but out of my price range. Jabaru 3300, same. I wanted around 80 to 100 reliable horse power.

 

The Subaru has a proven record for reliability as well as the following .

 

simple design .. one piece crankcase and cylinder assembly...no leaks from cylinder base gaskets

 

push rod engine meaning less complicated......parts are still available at a reasonable cost.......the parts needed for reconditioning are in some ways superior than the original because of advances in production techniques and materials (gaskets,pistons and rings and bearings). This engine has less bolts holding it together than almost any other engine i have come across, meaning that it goes together really well and is easy to maintain.

 

If anyone is interested,I can provide a step by step record of my engine from the strip down to the final completed item with accompanying photos on this thread

I am in need of help with wiring a distributor in or perhaps a different type of ignition system. ..thank you

I I made it