EA81 Tear down

[Guest Maj Millard]

Quote : "In the long term it could be fiddle with it or FLY it" Nev

 

Nev, I think that's what I was trying to allude to ????...........................Maj...

 

 

[facthunter]

yes Maj...

 

And I am in violent agreement with you. Nev.

 

 

[will kirkbride]

EA81 rebuild

 

Hi all. Moving my posts to this thread as it is more recent.

 

Some people just like to do things themselves as they like the challange or whatever. I commend Carl for at least having a go. I will add some photos of my rebuild so far including the redrive I am making. Cheers

 

 

[will kirkbride]

EA81 rebuild

 

I will try again with some photos

 

 

 

 

 

[Guest aussie carl]

AWSOME ! Thanks Will.

 

Could you also include where you got the products from and an estimate on costing.

 

I see you are making some components yourself. Nice one !

 

 

[will kirkbride]

Hi. Carl

 

The connecting rods and pistons for this engine are both custom items as getting off the shelf upgraded parts for this engine just doesn't happen.

 

The rods are custom Argo to my spec. and the pistons I am using are JE forged with the narrow rings off the later model EA81. I want to set the compression ratio so I can run on MOGAS with the option of maybe Ethanol mix in the future as who knows how long AVGAS will be available and I believe its only a matter of time before ALL unleaded fuel contains some ethanol.

 

This is one reason why I am going the auto engine route as i have control over how the engine is set up and have the option of tuning it for a different fuel in the future.

 

I hear all the negativity on auto conversions for aircraft and I believe a lot of it to be justified, however, there isn't a whole lot of difference between a Rotax 912 with a reduction gearbox and what I am doing apart from material that the Rotax is constructed from and it being a newer design. They still have there own issues, as nothing mechanical is foolproof or maintenance free. I am not knocking these or any other engines for that matter, its just personal choice.

 

Some of the problems I see from overseas owners of aircraft with these engines is the lack of proper procedures during the rebuild and general lack of knowledge about the importance of certain high stress parts. It is great doing these things on a budget, but you can't cut corners when depending on the engine to be reliable.

 

 

[Guest aussie carl]

I see you have a rally car in your avator so I am guessing you have done a few engine mods and are experienced with engine building.

 

The rods you are using look massive in comparison to the STD ones.

 

Can I ask what would a set of forged pistons and custom rods cost a bloke who doesen't have connections or know the right people.

 

 

[will kirkbride]

Sure Carl.

 

The rods cost about $400 each including GST and weight the same as the standard ones believe it or not. They have series 2000 ARP bolts as I was worried about the integrity of the standard ones whilst operating at 4000 plus RPM constantly.

 

The pistons cost about $850 with pins and clips. I am fitting Hastings rings. The pistons are forged and weigh 50 grams less than the standard ones.

 

Have you made a pin puller yet? Easy to make out of an 8mm long bolt by grinding the head to the right shape. If you get stuck, I will send a photo of the one I made.

 

Cheers

 

 

[Guest Baphomet]

I hesitated before relating this anecdote, because its not my intention to pour cold water on the idea of an aero conversion (there are many successful installations) BUT.

 

(Names ommitted to protect the innocent)

 

At the field I call home, there is a beautiful 701 with a Subaru up front. The present owner is not the builder, who had among other things, changed the cam profile and (I believe) increased the compression to 'improve' its performance. The result was an engine that required the use of Avgas, but other than that had been relatively trouble-free, for its first 100+ hrs. That all changed pretty quickly, there is still speculation about the cause of the first engine failure, but its probable the engine disagreed with a diet of mogas fed to it either in ignorance or error. The present owner engaged a mechanic (alleged expert builder of racing engines) to assist with the rebuild, and after considerable time and more changes to configuration, and at a cost of some $6000+ declared it 'ready'. When he learned it was going into an aircfaft, the mechanic dropped tools and walked away, leaving the owner with a pile of parts he then had to assemble himself. After assembly, the engine wouldn't start, and it was found after more time and inspection,that the new camshaft had been incorrectly ground. The machine shop ground another shaft and the engine was re-assembled and test run. Off for a test flight, keeping the field within gliding distance. That was a good decision, because when the second engine failure occurred, he didn't have far to push it back into the hanger. Another engine strip, and re-assembly (not sure what the problem was). This time, during the ground run, a problem with the gearbox (Hirth) was detected. When that was pulled apart, it was obvious the problem had been encountered before, because it appeared someone had used epoxy adhesive to keep components of the gearbox together. Another delay, waiting for new gearbox parts from Germany. Another test flight, and he's now chasing issues with carburation.

 

All of the above is reported as it was related to me, or my own observation. There may be errors in detail, but the gist of the story is correct. The long and short of it all is the present owner has had the machine for about 2 years, and in that time probably has only 2 or 3 hrs logged since he took delivery of it.

 

Moral of the story

 

1. Unless you have the experience, (or access to someone who does and will see it through to completion) don't f**k with it. Use off-the-shelf parts and rebuild it to original specs.

 

2. It will cost about twice your original estimate.

 

3. REALLY think about it, ANY change you make will have a flow-on effect.

 

In retrospect, it would have been better (and possibly cheaper) to have bolted on a 2nd hand Rotax 912. If nothing else, it would have improved the value of the aircraft, not detracted from it.

 

Baph

 

 

[will kirkbride]

Hi all. Happy to see this thread has started some interst.

 

I agree with most of what has been said in the above posts. Too many "experts" give advice based on their experience in a limited field, not counting all the missinformation that gets thrown around in racing circles.

 

In my case, I have spent many hours doing the reserch before deciding to go down this path. I would not recomend it to someone with limited knowledge of engines and their operating systems.

 

Dave. to answer your questions. I am going to fuel inject the engine with a multipoint set up. Engine management system with closed loop O2 sensor and baro compensation. This is fairly easy to set up with the sysems available now. Sensors include ,crank and cam angle,MAP, intake temp ,coolant temp and knock sensor as well as tach. I am setting the compression ratio at 9.5 to 1. I am hoping to get around 100hp at WOT but anything between 80 and 100 will be ok for my aircraft.

 

This is another consideration: what aircraft is the engine going to power. Mine is a STOL and fairly slow cruise so the torque of the engine is being set at around 4000RPM for cruise and the prop set to achieve this.

 

 

[Guest aussie carl]

Thanks for the info Will, I realy apperciate it.

 

Just to show some of the wear in this engine that has done 309000ks.

 

The center main jourmal on the crank is the only one that shows any signs of wear. in the center it is on top size according to specks but either side it is worn up to 0.035mm. Of course this crank would need grinding. But as I am not going to use it I am not going to bother.

 

On a side not there are plenty of gyros getting about with the EA81 motors, the seem to run them at cruse 4400 and max 5000rpm and are reporting that they will do this all day providing good oil is used and regularly changed and that the motors are pretty standard.

 

I have also been talking to a fella who has loged 400hrs on his EA81 which is pretty STD apart from 1mm taken off the heads and a cam. His rpm's are idential to the Gyro fellas.

 

Want to type more but have to go to work.

 

 

 

 

[will kirkbride]

Just wondering what you are going to fit the EA81 engine to? I am not a gyro type, but my understanding is that it takes a fair bit of constant power to keep them airborn.

 

Just an aside to this, I don't know how many EJ series Subaru engines are out there flying but i would not trust these in an aircraft as the cam belt timing set up is too prone to enexpected failure. There was a report of one going down on these forums a few months ago and i was wondering if anyone heard what actually failed on that engine.

 

cheers

 

 

[Russ]

Will...............must jump in here. Ej soobs, the 22's are bullit proof, last yr for example one chap logged near on 2000 +hrs mustering, never missed a beat.

 

Other 22's ( and there is a heap of them )............just keep on going.

 

The 25's are prone to head gasket failures, but after "the fix".......no probs to date. The 25's are yet to get big hrs up, so let's wait and see there.

 

Timing belt prob...............with regular attention to the idler pulley bearing, there is no prob. Change it out every 300hrs, prob fixed.

 

That recent gyro incident was not engine related, it was a busted rudder cable that allowed the rudder to lock full sideways somehow, all attempts by pilot to sort it were in vain, and nothing but tiger country under him.

 

Soobs biggest neg, is WEIGHT..........they have a shocker of power to weight ratio. Nothing surpasses the rotax here, and quite frankly the rotax is without dought, the premier engine plant for aero use.

 

The now 6 cyl soobs, are being installed into many fast fixed wingers, feedback is all plus.

 

If rotax pump out an engine 150hp thereabouts, their phone will go into meltdown.

 

Side note.............heard recently jabs are getting heads and cranks via china next yr, maybe just goss.......let's see

 

BTW............xmas cheers to all here. Good health, good luck, good times........russ

 

 

[bones]

If rotax pump out an engine 150hp thereabouts, their phone will go into meltdown.Side note.............heard recently jabs are getting heads and cranks via china next yr, maybe just goss.......let's see

BTW............xmas cheers to all here. Good health, good luck, good times........russ

Actually there is a way of getting 135hp out of the rotax easy, and reliablity is being proven now, some machines now reaching very close to 1000hrs.

 

The 914 rotax, can with a bit of tweeking, but basically in the stock form can and will produce 180hp, for how long is another question.

 

Bones

 

 

[bones]

Oh and I bet that gets Rotax's blessing NOT!!!!There goes your warranty, certification and TBO right?

Stick a hairdryer on anything and you can double the power, but what happens to reliability and life?? We all know the answer to that.

 

Until Rotax produce a certified 150 HP engine, (and it will be a lot heavier),they haven't got one. If you want 150 HP just buy an 0-320, proven reliable and available. It would certainly be my choice.

 

David

The fuel injected 914 rotax that the US defence use for unmanned aircraft have over 300000hrs combined, and they do pump out the full 150 hp.

 

Is that reliable enough for you, and you can get them for 20kUS ?????

 

I know of one ofr in Oz now.

 

 

[fly_tornado]

are those drones doing the same sort of flying as we plebs? I was led to believe that a lot of wear and tear in engines comes from the startup/takeoff cycle. I imagine those drones can stay aloft a long time

 

 

[facthunter]

current turbo Rotax.

 

The current turbo version has a 5 min limit on full power at 115 HP and very little boost. Those drone engines are expendable and the aircraft are unmanned. The 80 HP Rotax is the most bombproof model. The best way for Rotax to get more power is to add two more cylinders, but since the crankshaft is built-up and pressed together, it might be pushing it to go to six cylinders. The Jab and the Rotax have been designed in such a way that they cannot have larger stroke or bore without a complete redesign. There is no room to run bigger bores (unless you siamesed them, in the rotax and the crankcase would not allow stroking in either. (not enough room). Nev

 

 

[Guest Maj Millard]

I have been flying Rotaxs since 1984, including time with the little single cylinder 185cc Rotaxs as used on the twin-engined Lazair.

 

Knowing the way Rotax works after 28 years of using them, I would be very surprised if they wern't working on something around the 140-150 Hp area. my guess would be that it'll be either a further fuel-injected development of the current 100Hp 912 , or a completely new six or four cylinder engine.

 

Hopefully it will be simple like the current 912s, and not overly complicated like the 914. Rotax tends to take their time with engine development. That's why their engines are generally very reliable in the field, with only minor problems which they ultimatly fix.

 

....................................................................................................Maj...

 

 

[Guest aussie carl]

From hrs of searching on the net the conrods in the EA series go way back to the EA71 which is a 1600cc motor and remain the same rods right through to the EA82. I have not been able to find aftermarket rods for this series (apart from getting them custom made like Will has done)

 

The EJ series is a differnt story. Plenty of aftermarket rods are available, looks like Subaru used the same rods in the EJ18 right through to the EJ25 and 6 cyl motors as well.

 

I can see the std rods in the EA81 as potential problems especialy if they have been used used in a car for quite some time.

 

I have managed to find a supplier in the states who has new rods but more questions have to be asked before I make a purchase.

 

As some blokes have mentioned earlier in this thread an EA81 could end up being an endless money pit with heaps of modifations so I am not prepared to spend any cash just yet on custom rods for something that may not eventuate. More learing and talking to PPL's hopfully I will get to see some examples at Evans Head in a week or so.

 

On the Goldie ATM, kicking back. inside, out of the weather.

 

HAPPY AND SAFE CHRISTMAS TO YOU ALL.

 

Thanks for chiming back in Bones, thought we had lost ya.

 

The EJ22 has an excetional reputation in cars and have an EJ25 in my Outback but I feal the EJ series would be to heavy for a fixed wing LSA with MTOW of 544kg.

 

More looking and learing ahead.

 

 

[fly_tornado]

have yu looked @ a bmw k1200rs motor? stock they are good for 130HP. water cooled flat four with the exhaust below and FI above

 

 

[Guest aussie carl]

Thanks Fly.

 

Seen a thread only a few days ago on the beama motor whick looks impressive.

 

 

[Guest aussie carl]

More looking and it appears that the Terrier 200 utalises the EA81 motor and has done for some time.

 

Looks like they have made some modifications to the inlet and ignition systems to make them more reliable.

 

I'd say FoxCon would have done a fair amout of research and experementing/testing with the EA81. I have emaild them a week or so ago regarding there redrive but never got a responce, tried to call also but the phone only rang a couple of times then stopped.

 

There lack of responce leaves me fealing as though they either to busy or something has gone wrong.

 

Any Ideas !

 

 

[fly_tornado]

taken off over christmas and the voice mail full? interesting looking setup. that RE drive they make is impressive.

 

I noticed that Foxcon have made a coil on plug ignition for the EA81 engine.

 

 

[Guest aussie carl]

Yes there equipment is easily the most profesional looking and well thought out aftermarket accessories for the EA81 bar none.

 

Aparently there is a T200 hangered in Grafton, next time Tone flies up in the sting he has offered to take me for a look, It would be nice to find out who owns it so we could possibly have a better look.

 

 

[Guest aussie carl]

Thanks for the suggestions Dave.

 

I am not that savvie myself but am keen to learn, so a surfing I will go.

 

Off the top of my head not to many RA airframes will handle those sort of ponies and I think weight is pretty critical

 

The EJ series are pretty popular in gyros from my limited research.

 

The EJ20 out of a liberty might be a possibility. Now to find a wave.

 

edit EJ20 weighs same as EJ22. I will have a sticky beak on the gyro forum to see what they say.