Who's Flying With A Subaru

I have an EA-81 Sub-4 conversion.
My engine outs have been fuel related. 1 icing and 2 starvation.
The engine has been reliable but the supporting systems tend to create failures.
Same could happen to any engine in an experimental application.
I do recommend planetary gears.

One of the many problems that come up is things like re drives, you put a RAF type belt drive that puts side loads on the bearings and its a hand grenade waiting to go off. You put a rotax re drive with the standard manual flywheel and you then have a very reliable unit that has been my combination for around 3700 hours, these are working hours, not leisure flying so a lot of summer flying can be in plus 100F days.
Its very important to have a good sized radiator. I have a nissan pulsar radiator and temps never vary even on the hottest of days.
I'm a great believer in not fiddling with engines and definitely not in favour of putting in cams etc to get more more horses out of them. I have a friend who has gotten similar hours with two EJ 2.2's hours and mine still doest use any oil!

As far as relaiblity issues, I have never flown around something cause I thought the engine might quit and if I ever started thinking like that then thats the time I would quit flying gyros !! Having said that, I would recommend the rotax 912 /914's cause they are foolproof .....nearly....partly because they come as a complete unit and no one pulls them apart fiddling for extra horses and they have been designed to run all day at high revs.

Its essential good clean fuel is used and you have very good filters and change everything regularly. Because my 2.2 is EFI, I have two filters, one with a water trap and change them every 50 hours.

BTW, I would recommend the Autoflight gearbox behind the suby.

I have an Autoflight !

Been flying my Soob for a lot of years, no mods, straight out of the station wagon and on to the gyro. (I did change the cam drive belts, the engine had 50K miles on it.) Bensen style --- direct drive with 52/26 prop, and believe it or not, it flies my 250# butt around pretty good, even in hot weather. I do change the oil and filter every now and then!

James Lee - TN

James, from the sound of it (beltS) must be an EA82 ? Let's see some pics !

I fly a Subaru direct drive EA-81 and a Rotax 582 in a similar aircraft. The direct drive EA-81 has about the same consumption as the 2.54 geared 582 and about 50lbs more installed weight. I guess the 4 strokes efficiency is being offset by the inefficiency of running a 52" prop at 3500rpm instead of a 60" prop at 2500 rpm. The EA-81 static thrust is 300lbs while the 582 has 370lbs. As you might imagine the performance and flying qualities of the two are different. Really an apple to oranges comparison.

The 582 and the 532 that preceded it however have been reliable and involved less work during their lifetime than the sub. They have also had less engine outs. To many four stroke fans this may seem counterintuitive.

The reason is the Subaru was modified to fit the gyroplane and the gyroplane modified so the sub could be installed. The extra work during the lifetime was working out the inevitable teething problems of a new installation. They are still being worked out after 150hrs. The extra engine outs were due to carb and electrical shortcomings and not the core engines fault.

The final side by side summary is the 582 has proven more reliable, a better performer, same consumption at 14 lt/hr, less noise, easier ground handling

The sub hand starts and idles effortlessly. runs smoothly and without vibration even without a flywheel. It sounds great. It costs a quarter of the Rotax. No oil to mix. Lots of novelty appeal. A great learning experience.


I've also watched an ICP Savanah with geared EA-81 Subaru vs a Rotax 912 Savanah, and an Avid with geared EA-81 vs a similar one with a Rotax 912. In both cases the operation of the 912 has been more seamless than the EA-81. Less work, more expensive, better performance.

And finally on the aircraft engine vs auto conversion topic. I think the Cartercopter experience was indicative of what seems to be consensus but runs counter to the homebuilder dogma. The Cartercopter proof of concept prototype was built with a modified LS-1 GM engine with all the goodies and lots of engineering resources to back it. It proved to be a major hindrance to the developement of the project. The PAV Cartercopter which succeded it went with a certified Lycoming.

If you can afford it go for a purpose built aircraft engine.

If you can't; avoid opening the Subaru before installing it.

Just my experience I thought I'd pass on.

Dino

How many Sparrowhawk guys here with a Subaru ?

For CLS447

For CLS447

CLS447, remember I was probably the 2nd person in the US to put on an 82, 4th or 5th just putting on a Soob, so nothing fancy here, these are the pic you requested.

James

CLS447 more pic

CLS447 more pic

cls447 - more pic

COOL, are those 25' Skywheels ? 5' hub bar.

What carb on it ?

Direct drive & straight pipes ! Nice job ! Did you put many hours on it ?

Here's some pics

Hi Dino

If you are able, find a early EA-82 EFI intake manifold for your EA-81, they are a direct bolt on exchange and give a little better breathing than the EA-81 manifold and also put the thermostat on the front side of the engine away from the prop. I think it will be about a 1986 or 1987 model. Also if you can find a thermostat housing outlet from a EA-71 they are a direct bolt fit and much smaller than the EA-81 or EA-82 housing outlet.

Tony

Thanks Tony,

I had 2 Weber 32mm downdraught carbs right on the head intake ports. That and the Holly 1920 before it produced the same static rpm ergo power output.

I think the head design is such that it restricts the flow enough that it doesn't matter what you do upstream short of forced induction.

Dino

I am suprised you saw the pic. When I opened up and went to new post, they were not even there, this post was not there. the thread was not there either, I don't know where they went. Yes on the blades ---- Ford Pinto carb ---- Have around 500 hrs on it.

turbo 2.5 230HP

turbo 2.5 230HP

I have had an engine out because the fuel pump circuit breaker was to small for the pumps i was running,i went from a 2.2 carbed to a 2.5 and needed the high pressure pumps,forgot about the size of the breakers. my experience has been that the installation of the engines have to be aircraft quality work or you will be dealing with problems constantly.the soob engine is really a tough,well built engine,its when we start fiddling with it that the reliablety goes down hill. i fly at a lower rpm because of the increased hp, and i think my engine will have fewer problems with the lower rpm i use, i cruise at 39 to 4,000 an show a airspeed of 70 to 75. after takeoff i pull my power back to 4,700 and still see 60 mph and 500 fpm rate of climb.and this is at a density alt of 6 to 9,000 ft.best regards,eddie....

Eddie , do you have some pics of your installation ?

turbo 230 hp raf

turbo 230 hp raf

for pictures go to RAF forum/begining/threads,article is on the first page,thanks.eddie;;;

I found them !

A very interesting read here.

Tim your comments are certainly eye opening for a new guy.

Are there many users of the HKS700E? Any thoughts? (Just realizing now it's no where near the hp range of the engines mentioned above.)(Apples/oranges)

Jim

hks turbo charged

hks turbo charged

the other day carl schneider came down to fly with me in his gyro he has the 80hp turbocharged engine, it is really a nice setup and a really nice engine, runs and sounds great. eddie...