SUBARU engine

[pylon500]

Chasing info on gliders and found this...http://www.boonahgliding.com.au/subaroo.htmCan't seem to get my links active?Arthur.

 

 

[Guest micgrace]

Hi

 

I originally worked in a Subaru dealership as a mechanic

 

just after leaving school. Sure these engines are lightweight and

 

powerful enough for aircraft use, but there were more than several

 

drawbacks in the design.

 

Somewhat understrength conrods and

 

rather fast wearing vavle gear not to forget, they were also prone to

 

blowing headgaskets. Plus I did see many of them with burnt exhaust

 

vavles

 

On the plus side fairly quick to overhaul. I did do one

 

for someone for installation and was less than impressed with the

 

conversion kit which needed an awfull lot of mods to get it to fit and

 

work properly.

 

Naturally you can modify the engine to overcome

 

probs such as these, but in the end you would be better to buy a

 

certified engine anyway.

 

I often thought of getting a conversion kit for a 13B rotary engine. With conservative setup (standard porting)

 

and attention to oil supply these enjoy a fairly long life while being

 

fairly vibration free. Not to forget fairly compact. Much more so than

 

equivalent 4 stroke

 

To rebuild throw away the rotors and housings and c/shaft and thats about it.

 

With various sizes available 10a, 12a, 13b, 20b injected turbo etc wide range of power levels. (say 60hp to 300hp)

 

Naturally all models come with twin ignition. Fuel consupmtion closer

 

to a 2 stroke than a 4 stroke but I believe the potential is there for

 

some one who wants to have a go.

 

With a aftermarket injection (simple)

 

Turbo and reliable aftermarket computer with custom altitude

 

compensation could be very interesting.These engines can be xxxx loud

 

if modified.

 

I have noticed a lot of conversion kits available in the USA worth checking out for the more adventurous.

 

Micgrace

 

 

[pylon500]

Just out of interest, what sort of problems did you come across when working at Subaru on the EG-33 engine?I have one, still in the original car!And I would never take it out to put in a plane, the car is too good! Arthur.

 

 

[Guest micgrace]

Above engines referred to were ea81(ohv) ea82(ohc) The other eg33 is good, but I don't think that one has been converted for use (yet)

 

Micgrace

 

 

[Guest Fred Bear]

I showed a fellow aviator my new H6 3.0 Litre Subaru Liberty Spec-B

 

yesterday at the airport and he said "I see you are running in your new

 

aircraft engine."

 

It would go well in an aircraft, although I don't yet know how much it

 

actually weighs. It's 180 kilowatts and goes like a rocket about

 

4,000rpm and sounds good too. I have heard of issues with excessive oil

 

burn in them resulting in new short motor replacements, however I'll

 

keep an eye on mine if the oil level drops.

 

Tends to chew up the premium though; burns around 17lp 100kms around

 

town and 9 on the highways being driven in an average manner. Would be

 

interesting to see what it burnt in an aircraft. Suspect it would need

 

to be run consistently at 5,000rpm which would be thirsty.

 

 

[pylon500]

The EG-33 was actually fairly popular in the States in the bigger homebuilts, (usually supplied by Eggenfellner) like the 'CompMonster'This is an earlier Subaru engine of 3.3 litre displacement.Looking at the Eggenfellner site though;http://www.eggenfellneraircraft.com/Aboutus.htmIt now looks like he mainly deals with the new 3.0ltr H-6 found in Austarlia in the Outback series.I don't know what it's engine type designator is, EJ-30 maybe?Arthur.

 

 

[Guest micgrace]

EJ-33 found in Subaru SVX not imported/sold in Australia. Except as a private import. Engine can be had from Jap importers.

 

My

 

preference, and I'd like to see one in Australia is a 13B rotary in an

 

Aircraft. These things are xxx tough. Just go to the dragstrip to see.

 

More sensible would be standard porting. Naturally aspirated, Steel

 

rotor tip seals and engine dowelling

 

One mob in the USA sells these for aircraft use. From single rotor to double (13B) to triple (20B) and uses a geared PRSU to take 300+HP

 

Apparently quite a few in RV6,8,4 in various configurations.

 

Micgrace

 

 

[Guest micgrace]

Hi

 

Just a note on engine design/oil consumption. Unfortunately

 

just something you will just have to live with. The trend in car

 

engines is to reduce compression ring tension, by reducing thickness(reduces friction) gives free power or lowers fuel consumption.

 

Unfortunate byproduct is increased oil consumption.

 

Can be cured by the use of aftermarket pistons/rings (expensive)

 

Micgrace

 

 

[Galpin]

A subscription to Paul Lamar's Newsletter (free) gives one plenty to read and discuss on the Rotary engine. I am following a thread at the moment which is looking at "Turbo Compounding." This is somewhat beyond me, but it is fascinating to read the various opinions and ideas streaming form others who comment on this continuing development. Have a look at: http://www.rotaryeng.net if you wish. Micgrace your positive comments on the rotary are refreshing. Most comments I hear from "experts" are usually derogatory.

 

Do any of you have an update on Bundaberg's Stubbs Engineering development with a Subaru engine. Something is in the wind. Stubbs were involved with Sub4 in New Zealand. However, they have gone in a different direction with different products.

 

 

[Guest micgrace]

Hi

 

Not much really goes wrong with them. Main problems extend from incorrect oil. Oil pump failure. Leads to rotor tip failure rather fast.

 

For the faint hearted, usual practice is to wire the oil injection pump open and add 100:1 oil mix to fuel.

 

Of course a good quality oil cooler helps as well.

 

Compression testing is a problem, and you have to buy a special compression guage due to the very different way compression is achieved.

 

A very simple aftermarket injection system available locally (injection perfection) available. Little more than 2 injectors in a throttle body. plus a relatively simple direct fire 4 coil ignition (2 plugs per rotor, 1 leading, 1 trailing) Mind you they will run on either, but not as well.

 

Plus it is possible to run a separate computer for each rotor for added safety. Possibly the best way would be a separate fuel only computer with a separate ignition computer for each rotor.

 

With some porting changes from standard i.e. to no more than slight plus a fairly open exhaust (xxx loud) Much more power to be had.

 

There are some oyher changes as well, but a rotary expert may tell all.

 

Such as engine dowelling etc

 

For aircraft use I'd keep it relatively standard.

 

Injection really suits these engines and is not that hard to set up. Need to provide a lift pump to an external swirl pot/header tankto a injection pump. Or double it for safety. This can be channelled into 2 points on the fuel rail for safety. These can be left to run full time. But have a separate switch to test each one individually. If one fails, the result is near instant engine failure.

 

Of course, fuel filtration will need the use of a primary coarse filter, plus the use of a micron filter for each pump. Plus the use of high pressure fuel line (very important)

 

There are prsu units from the states to suit 13b (the most prolific version). Plus all sorts of ignition/computer types available. Plus any component rad shop will soon knock you up a radiator.

 

These things have come to virtually dominate the small classes of road racing. More often than not. The drive train explodes, but rarely any engine problems provided the setup is correct. It is quite common to see these in drag racing developing 2000+ hp with little more than porting/turbo/steel tips/dowelling on the engine. Try that with your average piston engine.

 

I'm very tempted to actually use one of these myself, but the high cost of the prsu puts me off a bit.

 

Micgrace

 

 

[bushcaddy105]

I fly an EA81 with a belt redrive, and am getting comments from pilot passengers that it is the smoothest, quietest engine they have ever flown behind, despite being hung on fairly stiff urethane bushes in an all-metal aircraft.

 

The main penalty, when compared with a 912, is approx 25 kilos extra to carry by the time you add radiator and coolant (although my radiator is clearly bigger than it needs to be)

 

The biggest plus is the cost, or lack of! I had 2 engines given to me, and picked up a third for $40 out of the local paper. A full rebuild kit - pistons, rings, gudgeons, small end bushes, main and big end bearings, all gaskets and seals costs $420.00 from SupaCheap, and thats for an Australian ACL package. Add about $60 each for a new water pump and oil pump and you have a zero time engine for under $600

 

The other plus is that EA81's simply don't break - they are bulletproof

 

 

[Guest secatur]

Hi John,

 

What redrive are you using (cost?) and what is your total engine weight?

 

Thinking of EA-81 in Zenith 701, but worried about the weight!

 

Thanks,

 

Steve (701 in Perth)

 

 

[bushcaddy105]

Gooday Steve,

 

After much headscratching, I chose to use a Foxcon redrive, as used on the Terrier 200. E-mail Foxcon direct for current price, as it has probably changed since I bought mine. I also used their prop hub and spinner, with blades from Bolly. Now has 68 hours flying on it and has been trouble-free (and incredibly smooooth!). The weight of my EA81, including redrive, starter, alternator, engine mount brackets, manifold, carby and oil (As weighed to calculate Weight and Balance for engine truss design) is 92 Kilos.

 

To this must be added the muffler (My own home-brew one weighs 2.5 Kg) and the radiator, coolant and hoses. I guess about 100 Kg all up

 

Hope this helps

 

John B

 

 

[Knighty]

Hey guys. I hope I am not too late throwing in my 2 bobs worth as I only just read this thread.

 

The all up weight of my EA 81 was 118kgs, this includes a 3 blade Ivoprop 70 inch magnum (no other prop on the market at a reasonable price could harness the 140 HP engine, BIG PROP VERY HEAVY BUT STURDY), spinner, 160 HP autoflight PSRU (sub 4), radiator and all powerplant fluids.

 

If you are after some serious horsepower versus weight this Ram unit of mine (came with a price tag and a lot of bullsh@!#$% around to get it here!) would appear to out perform other EA81's on the market today even the turboed units. If I had my time over again I possibly would have settled for an engine straight out of a Brumby ute and rebuilt it myself for a fraction of the price and weight. I had to go BIG with props and redrives because of the shear grunt of this engine, most redrives/props are only recommended for 120 HP max and weigh bugger all compared to my running gear. I hope this helps you with your decision.

 

Knighty

 

 

[stol1]

Gooday Steve,After much headscratching, I chose to use a Foxcon redrive, as used on the Terrier 200. E-mail Foxcon direct for current price, as it has probably changed since I bought mine. I also used their prop hub and spinner, with blades from Bolly. Now has 68 hours flying on it and has been trouble-free (and incredibly smooooth!). The weight of my EA81, including redrive, starter, alternator, engine mount brackets, manifold, carby and oil (As weighed to calculate Weight and Balance for engine truss design) is 92 Kilos.

To this must be added the muffler (My own home-brew one weighs 2.5 Kg) and the radiator, coolant and hoses. I guess about 100 Kg all up

 

Hope this helps

 

John B

I am building a zenith 701, and have (4) ea-81 motors at my disposal, one with a rfi belt re-drive, and a fresh build on the motor. If I run this engine, it will have a spg re-drive, 24 lbs, less starter, a custom flywheel, 8 lbs or less, a carbon fiber intake, with a aeroinjector, maybe a aluminum oil pan, and aluminum pulleys, and a 20 amp permanent magnet generator.3 lbs . I will also be using aeromomentum's radiator, and am undecided about the prop. I have looked at exhaust but am also unsure there. A cam re-grind, and head work, hopefully will put me at 100 horses. If I go this route, I hope to see weights in the 170 pounds even if I have to cut off unneeded bosses on the motor. What are your ideas/ suggestions?

 

 

[bushcaddy105]

As previously posted, I think your expectations for an EA81 are too high, both in weight reduction and power output. I personally prefer a bit more weight and a bit less power for the sake of reliability. This formula has worked well for the 12 years and 750+ hours I have been flying behind my EA81. (This is my conversion, not a commercial one).

 

 

[stol1]

As previously posted, I think your expectations for an EA81 are too high, both in weight reduction and power output. I personally prefer a bit more weight and a bit less power for the sake of reliability. This formula has worked well for the 12 years and 750+ hours I have been flying behind my EA81. (This is my conversion, not a commercial

Can you send me some pictures of your installation? What did you do to your engine. I plan on doing my conversion, any suggestions would be appreciated. Thanks