Subaru EA 81

[Adrian Lewer]

Hi all, I am looking at buying a used Subaru EA 81 motor. The motor has no log books but is said to be in good condition with good compression. The owner does not know how many hours are on it as he bought it on an "as is" basis.

 

The question is. What do I have to do to bring it to a 0 hour STD or even just to give it a freshen up ?

 

Where would I get the parts from ? Subaru ?

 

What would be involved in an overhaul "parts and dollars " ?

 

Cheers.

 

 

[Bubbleboy]

Hi Adrian...John Birrell who goes by the name of "Bush Pilot" if I recall on here is the man you need to talk to. He presented a fantastic seminar at Natfly on the Subaru conversion and then showed us his immaculate example which he flew there. From what he was saying the cylinders never wear out. Parts from Super Cheap Auto and the like. Apparently you need a modified cam, he also modified the distributor and used a different intake manifold on his. I think he had a radiator off an Alfa Romeo (hope my memory is serving me correctly). He has a Foxcon belt redrive fitted to the front. I was very impressed at the setup.

 

He said he has fantastic reliability from his one.

 

Hope this is a start anyway.

 

Scotty :thumb_up:

 

 

[peter]

Hi Adrian,

 

i run a Subie EA 81 in the COBRA, I had it fully rebuilt by a performance workshop in Adelaide, has modified cam, twin bings and custom exhaust, using an amax redrive and inflight adjustable bolly prop -- engine time 70+ hours since rebuild.

 

To keep the plane in balance I have 15kgs of lead in the nose. I like the Subies so much I am currently rebuilding an EJ22 which I intend to swap over and lose the lead out of the nose -- more horse power same overall weight -- I am going to use an autoflight redrive -- I will begin the changeover next month I think.

 

If you are interested in the EA81 +redrive give me a call - it will be going pretty cheap!!!

 

It runs very well, spins up to 6000rpm on takeoff, remaining smooth as...,.sounds amazing.

 

Cheers

 

Peter

 

mobile 0428779699

 

 

[Adrian Lewer]

Have spoken to Peter and we will hopfully continue our coversation tonight. I will also shoot of a pm to John ( bush pilot ) as I would like to still play with the cheap one for hands on experience.

 

Thanks guys and if anyone has anymore info please feel free to post here.

 

 

[Tony2]

You may need manuals? Joh has been so kind to make these available to everyone

 

Subaru Documentation

 

 

[bushcaddy105]

Gooday Adrian,

 

I'm the BushCaddy driver (bushcaddy105 - bushpilot is another forum member). I have 380+ hours on my Subaru conversion, and am quite happy with it. Some time ago I posted all details and specifications of my setup in the Engines section of these forums - do a search on "Subaru" and I'm sure it will come up. Otherwise pm me for a phone number to contact me on.

 

 

[Adrian Lewer]

Hi everyone, I have spoken to "bush pilot" but it was not him ;). Felt like a complete dickhead writing an essay Tobin and getting " no John here " I had a chucckle to myself. Thanks for putting it out there Though bubbleboy much appreciated. Well thanks for jumping in the thread John much appreciated but I have a couple of questions. Do I need a wiring loom for one or will a motor straight from the car work with a home made loom for the dizzy, starter motor ETC if I need the one from the car which part of it or all of it ?

 

This is what I am thinking of doing based on what I have read and heard. please but in if you have any comments.

 

Buy a running motor even if it is in need of attention. Remove from car and mount on test stand

 

Buy a redrive reduction unit, EA82 inlet manifold,Wade 240 cam

 

1.75" SU carb,EA71 crank pully,

 

buy new rings, bearings have the cylnders honed, have the heads decked by 1mm, acid wash parts and re assemble myself.

 

My only concearn is the distributer. What type ? What modifications ?

 

After it is built test the engine on the stand with prop.

 

What timing should be used ?

 

Cheers.

 

 

[Bubbleboy]

Hi Adrian...sorry about that mate, I got the "bush" part right. I did mention I was hoping my memory was serving me correctly. Obviously wasnt when I typed it!

 

Hope it all goes well from now on :pc strikes back:

 

Scotty

 

 

[Adrian Lewer]

:hittinghead:

 

 

[will kirkbride]

Subaru EA81

 

Hi 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

 

 

[will kirkbride]

Subaru EA81 update

 

Just an update on the progress of the Subaru engine for anyone interested.

 

After strip down and measuring, the block halves were machined and line bored, including the camshaft and oil pump housing.

 

All threads were helicoiled to improve reliability.

 

Custom steel con rods with larger bolts , ended up the same weight as the originals.

 

Forged pistons with narrow rings for less friction. weight of these were approx. 50 grams lighter than the Subaru cast pistons.

 

Block was machined for zero deck height for the pistons. Rebore and honing of cylinders to .5mm oversize.

 

Crankshaft was polished and measured. As there was no wear, journals were linished.

 

Next step is to balance the rotating assembly after the redrive is finished. [ATTACH]12141.vB[/ATTACH][ATTACH]12142.vB[/ATTACH][ATTACH]12143.vB[/ATTACH]

 

 

 

 

 

[EagleTrike]

Hi Will

 

I would be interested in finding out the finer details of your experience with the EA81, like where you sourced the parts from, things to look out for, etc., as I plan on putting myself through a 0 timed rebuild of a EA81. I am planning on running in it in a scratch built trike. I am sourcing the parts for the airframe at the moment so hopefully will start building shortly.

 

David

 

 

[will kirkbride]

David.

 

Have had a lot of experience with Subaru engines. Aftermarket parts are still available at reasonable prices. The only part hard to source is the oil pump if you should need a new one. My engine has custom pistons and con rods, however ,standard cast pistons in oversizes are still available. I will be posting new pics as I progress with the rebuild but feel free to ask any specific questions and I will do my best to help.

 

cheers

 

 

[Guest aussie carl]

David. Have had a lot of experience with Subaru engines. Aftermarket parts are still available at reasonable prices. The only part hard to source is the oil pump if you should need a new one. My engine has custom pistons and con rods, however ,standard cast pistons in oversizes are still available. I will be posting new pics as I progress with the rebuild but feel free to ask any specific questions and I will do my best to help.

cheers

G'Day Will.

It would be great to hear of your progress and where you sourced the performance parts from.

 

Thanks Carl

 

 

[AirWolf]

Subaru EA81 updateJust an update on the progress of the Subaru engine for anyone interested.

 

After strip down and measuring, the block halves were machined and line bored, including the camshaft and oil pump housing.

 

All threads were helicoiled to improve reliability.

 

Custom steel con rods with larger bolts , ended up the same weight as the originals.

 

Forged pistons with narrow rings for less friction. weight of these were approx. 50 grams lighter than the Subaru cast pistons.

 

Block was machined for zero deck height for the pistons. Rebore and honing of cylinders to .5mm oversize.

 

Crankshaft was polished and measured. As there was no wear, journals were linished.

 

Next step is to balance the rotating assembly after the redrive is finished. [ATTACH]12141.vB[/ATTACH][ATTACH]12142.vB[/ATTACH][ATTACH]12143.vB[/ATTACH]

Hi, I am rebuilding an EA 81 and would like to know more about the custom con rods and where they are available from. Cheers Ray.

 

 

[will kirkbride]

Hi, I am rebuilding an EA 81 and would like to know more about the custom con rods and where they are available from. Cheers Ray.

Hi there Ray. The rods were custom made by Phill at ARGO engineering in Morphet. They were the first of these rods to be made for on EA81 as

I recall(the standard ones would probably be more that strong enough) but I wanted peace of mind. PM me if you want more details. Cheers Will

 

 

[AirWolf]

Hi Will,

 

Thanks for that info, I will chase up Argo and see if they still have the drawings. Were they made the same length as the standard rods or were they longer? My thoughts are if you are going to make new rods ,longer ones would enable you to have a shorter piston thus reducing the rod angle, just my thoughts.

 

Thanks again Will, cheers, Ray.

 

 

[will kirkbride]

Hi Will,Thanks for that info, I will chase up Argo and see if they still have the drawings. Were they made the same length as the standard rods or were they longer? My thoughts are if you are going to make new rods ,longer ones would enable you to have a shorter piston thus reducing the rod angle, just my thoughts.

Thanks again Will, cheers, Ray.

Ray,

The rods were standard length. I doubt that making a long rod type engine would be much advantage because of the short stoke of this engine. The ring pack is quite compact as it is and if you want to use available pistons, it would not be a economical option. If you are serious about using this engine, there is a heap of information on the net.

 

I have mine running now and am in the ground testing stage. So far it looks good. I am happy to share any info. Cheers Will

 

 

[facthunter]

To reduce rod angle, by lengthening the rod requires the gudgeon pin to be located higher up and more piston skirt load and non standard pistons. AS you are not going anywhere near maximum revs you should be OK with new original. (or low time crack tested). Maybe better bolts. Nev

 

 

[Marty_d]

For those of us not mechanically adept, are there any businesses out there that recondition & convert the EA81 engine, put it on an engine mount and bolt a prop to the front, test it and then sell it?

 

 

[bexrbetter]

For those of us not mechanically adept, are there any businesses out there that recondition & convert the EA81 engine, put it on an engine mount and bolt a prop to the front, test it and then sell it?

Yes but be wary of the hp claims, there is no way they are going to turn 100hp with the standard log manifold on single port heads as some claim, more likely in the 75 to 80hp area. The very rare Rally engines with twin ports and carbs were 100hp (you won't find one but Rams Engines make twin port heads for them).

 

Ha, I was going to get Rams Engines info for you and it led right back here!...

 

http://www.recreationalflying.com/threads/subaru-ea81-conversion.8488/

 

Notice a report on a broken conrod, that is virtually unheard of in a Subaru and I wouldn't be concerned about it.

 

 

[zenith 701]

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

Hello I read your reply to a fellow and I'm interested in type of ignition system. ..thanks for your help

 

 

[AirWolf]

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.

 

 

[zenith 701]

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.

[zenith 701]

Hi ray....this is mike..thanks for your time..is the haltec 3 d compatible with a carb set up....also would you happen to know the company that makes it...thank you for all your help ....I live in usa