EA81 Tear down

[Guest aussie carl]

Well just thought I would share my tear down and inspection.

 

I will be following THIS manual for checking for spefications and wear.

 

As I am not certified to work on it for aircraft use then I will have to wait till then to put it back together

 

Bought an EA81 from the wreckers, came from a 89 Brumby Ute.

 

Ripped most of the unused stuff off and gave her a scrubbin to clean the oil n muck off,

 

she has done a few K's 309000 but we will see just how much it is worn or damaged apon inspection.

 

Have to get it up on an engine stand to go any further

 

Feel free to chime in.

 

 

 

 

 

 

[Russ]

3 pieces of info..................

 

1st..................checkout "Flysoob" good site dedicated to aviation soobs

 

2ndly...............stear clear of of a guy via Bundaberg ( PM me )

 

3rdly................keep desired HP to a max 85ish or less .....rotax 2.62 matches a EA81 just great, with 76" warp drive

 

 

[Guest aussie carl]

Hey Russ thanks. STD they are 85HP, I thought the STD thing to do was get 100 out of them. Machine heads, different cam and Carb.

 

Yep found fly soop but its a yahoo group or something and that turnes me off, unless I have missed somerthing.

 

A rebuild kit is relatively cheep $400-$500

 

 

[Russ]

yet to see a EA81 that is STD 85hp..............more like 65. ( non turboed )

 

You bump them to near 100hp...............reliability goes out the window. They just don't like it that high.

 

At absolute max 80ish HP........they will run at 4000+ all day. Brumbies had better heads....bigger valves....better porting............

 

Polish the ports up, warm cam ( ground to produce torque/power at YOUR best desired need )

 

Beware fretting between the 2 crankcase halves, make sure the pins are reeeel good. Put on a GOOD carby, speak to a genuine exhaust guy for ultimate system ( breathing is a major point for the soob )

 

That's about it.........................keep away from 100ish HP

 

 

[Guest aussie carl]

Hey thanks Fellas. I will take it all on board. Glad I posted as your info is the juice I need to hear.

 

In the manual though it quotes 85HP @ 4800 rpm for the naturaly asperated version.

 

The manual I posted has wear limits,When I get the rotating and recprocating parts out I will make decisions based on these specs and prices for engine machining, If I have to bin it then I am OK with that.

 

Can get parts xrayed for $0 so will be doing this also, but will dye pen first.

 

 

[Guest aussie carl]

Well the heads are off, bores are 92.10mm which is out spec.

 

But what concerns me is there is a busted pushrod for one cylinder and another cylinder has injested something dinting head and piston.

 

I don't trust this one for an aero conversion as it may have other hidden flaws. and will just pull it apart for the exercise.

 

 

 

 

[stanzahero]

Looks like the cylinder has done a spark plug electrode. The damage is confined to the squish area in the chamber.

 

 

[Guest aussie carl]

Thanks Stan, a good sign that the engine has not been maintained.

 

 

[bones]

1 question why bother?? like i mean to say, how much is your neck worth? get a real engine, simple.

 

 

[facthunter]

Damage.

 

The busted push rod is probably due to a rusted up exhaust valve guide/stem. This can happen if the engine sits for a time and is started up again without checking.

 

A spark plug electrode can come off anytime. The head could be cleaned up in the squish areas and the pistons will be replaced anyhow.

 

The problem is that this engine (and many others) has done a lifetime of work and that is hardly a good precursor for putting it up the front of an aeroplane. If we give a 1 for 2 conversion the engine has the equivalent of 15,000 hours of work under its belt. No engine improves with age and use. (like a bottle of wine does).

 

I would not like to rebuild a certified aero engine (piston) that has more than 6,000 hours total (3 normal TBO's). Fatigue doesn't show up with most NDT ( non destructive testing) processes and cylinder heads often go soft and have to be discarded in the normal auto engine reconditioning environment. You can test for cracks and scratches. If there is any fretting of the mating faces of the crankcase they have to be machined and the affected main and cam bearings align bored.

 

I would also replace all conrods and the crank if economically feasable. Nev

 

 

[Guest aussie carl]

Thanks Bones.

 

I could ask. Why bother or I could ask. Why don't I get a real aircraft, but I won't ask that question. A GA pilot might though.

 

 

[Guest aussie carl]

Thanks Nev.

 

I'm hearing you.

 

You input is well recieved.

 

This one is for learning.

 

Carl

 

 

[Guest aussie carl]

Bit rough Bones .... not everyone can afford a $30,000 engine mate.David

Yer and I had to edit my post as my inital responce was not so polite.

Nev. You got me thinking overnight.

 

New rods and new crank would be the way to go I will look around. But I will also still keep looking for a motor that is in better nick to start with.

 

I also know a bloke localy who was a Subaru/VW specalist from early 80's to mid 90's, It might be worh while to give him a call.

 

 

[Thirsty]

I agree, I would replace pretty much everything but the crankcase. Then again, seeing as how not much money is tied up in this engine you might be better off looking for another. You could probably buy a whole Brumby/Leone, take the engine out and sell off the rest as spares and maybe pay for the engine.

 

As an interesting aside - BMW used to base their 1.5 litre F1 turbo engines on blocks out of BMW 2000 model cars that had done quite high mileage. Apparently the idea was if it hasn't brkoen by now it never will :) If anyone is interested I can dig out the article and scan it.

 

 

[facthunter]

BMW road engine.

 

Thirsty, you are right about that motor. It was just a production engine. Cast iron (and that was the common block material then) does not fatigue nor it seems does Nodular Iron which is used in car crankshafts. These materials are not used in aircraft engines because their strength for weight considerations would rule them out as they would have to have heavier/thicker sections to get the strength.

 

Aero engines use heat treated fairly exotic aluminium/magnesium alloys for crankcases and nitrided steel alloys for the cylinders and crankshafts.. Due to the emphasis on light weight these engines are highly stressed and should be discarded at some point . (I would suggest at the second life run-out). This doesn't mean that they are "crook" engines, but they are designed for a specific purpose. Nev

 

 

[bones]

Bit rough Bones .... not everyone can afford a $30,000 engine mate.David

 

Yer and I had to edit my post as my inital responce was not so polite.Nev. You got me thinking overnight.

 

New rods and new crank would be the way to go I will look around. But I will also still keep looking for a motor that is in better nick to start with.

 

I also know a bloke localy who was a Subaru/VW specalist from early 80's to mid 90's, It might be worh while to give him a call.

Like i said get a real engine, i DID NOT state what type there are different engines for the job under 30k.

 

I also did state i factual question though, how much do you value your neck???

 

I will leave your thread alone now cheers.

 

 

[Guest aussie carl]

Tis all good Bones. It is hard to express over a keyboard.

 

 

[Methusala]

EA-81 for sale

 

G'day Carl,

 

We have for sale an EA-81 that has been FULLY rebuilt (new pistons, Wade grind cam shaft, rings, bearings etc etc) by a very careful and perfectionaist mechanic. We only put 20 hrs on it as it was just too heavy for our requirements. It is fitted with a brand new C-type Rotax box 2.62:1 and has fuel injection via Haltec F-9 programmable computer. It is listed in the classies. Please feel free to PM me or phone on 0414626700. Cheers Don

 

 

[Guest Maj Millard]

I owned and drove three EA-81 powered Subbies in the past. The last one had an engine that run so sweet, that I swore that I was going to put it into an aircraft one day....it didn't happen.

 

Like the venerable VW before it, you would assume that the EA81 should be perfect for aircraft use, and no doubt there are many cases out there where they have been very successfull.

 

But unfortunatly they have appealed often to the same type of folks that the VW did, with unfortunatly often the same results....a lot of messing around, quite a few notable failures, and not a lot of flying in the big picture.

 

The best usage of them seems to have been in Gyrocopters, and the worst in the Terrier with owners constantly struggling to keep them from overheating in the air.

 

One owner up this way took about four thou off the tops of his pistons, fitted a Starion Turbo (only used about 4 pounds of boost) and put the engine on a very large Gyro of his own design, that I can garantee you took every bit of 100 hp to fly !. The sound of the little lightly turbo-charged EA81 at full tilt is still etched in my brain.

 

The addition of the correct after-market cam can also make them into a lovely little aircraft engine.

 

Like Bones probabily, I am past wanting to build up my own aircraft engine ( don't worry, I've done it ) and would rather work a few more hard hours to afford a real one up front.....and just do some flying these days !............................................maj...

 

 

 

 

 

 

[Guest aussie carl]

Thanks Don. I had a look.

 

Part of the fun for me is the rebuild. $4K is pretty reasonable considering but then I would have missed out on a rebuild and would be nun the wiser.

 

However if you will accept $2K then that's a different story.

 

<H2 class="posttitle icon">SUBARU EA-81 Revised Price!

StatusOpen

TypeFor SalePriceAround$4,000LocationCanberraConditionExcellentContact No0414626700

 

Payment TypesCash, Bank Transfer

 

 

Subaru EA-81, EFI, Rotax 2.58-1 C-Type gearbox all accessories incl. Warp Drive 68"x 3 blade, Haltec F-9 programmable ECU. Engine has been rebuilt by a very conservative mechanic. Was installed on Karatoo but we decided it was too much weight for the airframe. Did 20 hrs in the air. Ph.0414626700 or

 

[email protected]

</H2> Need to make a puller to remove the gudgeon pins, in the manual it just looks like a slide hammer with maybe a tab on the end to pull the pin out.

 

edit Nice Maj. Love that Bipe

 

 

 

[Methusala]

Dear Maj (and others of course), What bilge are you sprouting about the loveliest little 4 cyl horizontally opposed engine that anyone ever breathed life into? I flew a Volksplane with a Revmaster (perhaps not the best conversion ever?) and then a 2040cc Aeropower all over the place with almost boring dependability and my friend has a Cygnet with an 1835 that he did all by himself. Both engines have done over 400 hrs with very little apart from regular oil changes and tappet adjustment. The problem seriously is the nut behind the crank expecting too much performance and not being sympathetic to the machinery. Yours in expectation of a vigorous reply, Don.

 

PS Carl. I like your style, heh. Seriously though it is all about the money, admit it.

 

 

[Guest Maj Millard]

Don, Yes I would have to agree with you that there are plenty of success stories out there with the VW in aeroplanes, I myself have time behind them. I have always seen the EA81 as the jap development of the VW anyway. In fact if you look at the VW, Suburu and 912 crankshafts side by side, there is very little difference really.

 

I just prefer to see people flying these days instead of them busting their knuckles in the garage, with an auto conversion. However if thats what they wish to do, then i wish them well in their efforts.........................................................Maj...

 

 

[Guest aussie carl]

Meth. Yep I'm built like a fish.

 

Nah seriously I have always been a builder/fixer of all things. Guess that is why I became a Fitter/Machinest.

 

 

[Methusala]

Carl, I'll accept that. Have a good one!

 

 

[facthunter]

Fiddler Vs Flyer.

 

I tend to be an engine fiddler too.

 

You put a plane in the air and depending how you go about it, you are test piloting very little (ie an OFF the HOOk complete proven design). OR You can test fly the airframe.(modify or rebuild or design your own, but fit a proven engine.) OR you can test fly both the engine (IFyou adapt one,) and airframe together. The latter is not generally recommended.

 

The general view of builders in retrospect has been (within SAAA and similar builders organisations) is to fit a proven engine and get in the AIR so much quicker and in many cases LESS expensively. It's not just the engine . It's the redrive, the mounting of it exhaust system. getting the drive from the engine, mounting accessories,Getting a suitable and SAFE propeller etc. IF you could access a firewall forward kit it would be much simpler but you end up having to work it all out for yourself. Lonely brain numbing work.

 

In the long term it could be fiddle with it or FLY it. Nev