Is the subaru ea-81 history?

helicopter ed

helicopter ed
Joined
Nov 8, 2010
Messages
210
Location
Hamilton, Oh
Aircraft
Gyrochopper1/Air Comm. single/AC side by side/AC tandem. All powered by Subaru EA-81 100 HP
Total Flight Time
4000+ all rotorcraft.
FOR 1000'S OF HOURS ON GYROS, ALL 2/STROKES ARE POT METAL JUNK...

Not hardly a soul doing anything with the EA-81 any more. Here are the rules to make the EA-81 a good choice. Pilot wt 180, [less is better]. Empty weight 350, [less is better]. Prop, Warp 60" set at 6* on tips. Prop RPM 2600 climb, 2200 cruse. Rotor, 24" Rotordyne or Skywheels or Extruded [[8 H -12] rotor. No other rotor I have tried will give good climb. The secret to marginal power is a good rotor. Stock carb and manifold, holly 1920, or Pinto holly 2 barrel progressive work okay. I like the Pre 1980 1700 cc point dist. for ignition, stock elec. ign do not have hot enough spark for hand prop.

In thousands of hours on my own 3 engines, only a .67 cent expansion freeze out plug one time has been my only expense. Near 30 intallations over the last 20+ years, with a 2 year guarantee, never had to replace anything for all those men. A most perfect engine has never been, till the 912, but that baby is above our pay grade. No prop hubs left anywhere. Herman Yates' said he got Ora Cooks' last one...
 
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Mike Hook

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Navarre, Fl
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Dominator
Ed
I have a 83 ea-81 that I intend to have for a long time. Just getting started on ordering new seals and bearings.

How did you set up the holley carb on Dougs gyro?

Thanks

Mike
 

BUD ONEAL

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Nov 2, 2003
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Ider, Al. 35981
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Dominator
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600+
I have a EA 81 100 hp with the jugs bored 10 thousands over,new rings and all rod and main bearings new seals all around. Has chevy 350 solid lifters with the standard 100 hp cam. areo flight redrive 2-1 I believe. Jake built the intake . This engine is a little power house. I have about 10 hrs on it now.
 

Mike Hook

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Dominator
Bud

Did you have to modify the engine for the chevy solid ifters?

I see that Ed uses the stock intake but I also hear the the ea-82 intake has larger intake passages, Stilltrying to figure out what intake to use.

Mike
 

BUD ONEAL

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Ider, Al. 35981
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Dominator
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It had hyd. lifters in it but kept leaking down when it set overnight and I replaced them with solid. Yes the lifter holes had to be bored out to accept the chev lifters. It now is a little power house.I have only once had it to full power for take off.
 

WHY

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miami,oklahoma
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HI Bud

Would be interested to know if you kept the original cam that was used with the Hyd. lifters. Way back when the EA-81 was just starting to be used I knew 2 guys from up Northeast way named Jim Bauder and Herb Clark, both had essentially the same gyro, weighed close to the same, same blades. same prop and carb. But one gyro would noticeably out perform the other. For a long time I could not find out why and they did not have any idea. I looked at several overhaul manuals and could find no reason,-------until I finally got a hold of a Fuji factory shop manual and there it was. One engine came from a vehicle with a manual transmission and the other from a vehicle with a automatic transmission. The engine from the car with the automatic transmission had hyd lifters and a had a different cam grind that raised the torque about 200 rpm higher on the curve chart, this was the one that had the performance, subsequent conversion have confirmed this feature, in fact some of the "aftermarket" re-grinds are very close to the one used on the hyd lifter set up.

Tony
 
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WHY

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miami,oklahoma
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Ercoupe and Cessna 150, 152, 172, 140, Aeronca,7ac, Citabria,Chief,Piper PA11,PA12
Total Flight Time
215
If there is anyone out there who is a "new" PRA member and interested in converting a EA-81 for use on their gyro,---- go the the PRA website and search around the mid 90's in the magazine. In the early 90's I produced a conversion package for the EA-81 and a manual to do the conversion, Ed Alderfer marketed it thru "Whirlwing". There was quite a bit of interest then so I turned the manual over to the PRA and the editor published the entire conversion manual in the magazine as a "series" of feature articles over a span of about 5 or 6 issues (I think ?) The conversion package is no longer in production but the info on the conversion procedures would still be available to any PRA member as a down load.

Tony
 

Mike Hook

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Thanks Tony
I will try and find that series. If I can locate it I will save it in one document for others to use.

Mike
 

Mike Hook

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Just checked the pra archives for those issues that year. They have not been scanned in yet. Maybe someone with a stack of back issues could find the article and post them here for all to use.

Thanks Mike
 

BUD ONEAL

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Ider, Al. 35981
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HI Bud

Would be interested to know if you kept the original cam that was used with the Hyd. lifters. Way back when the EA-81 was just starting to be used I knew 2 guys from up Northeast way named Jim Bauder and Herb Clark, both had essentially the same gyro, weighed close to the same, same blades. same prop and carb. But one gyro would noticeably out perform the other. For a long time I could not find out why and they did not have any idea. I looked at several overhaul manuals and could find no reason,-------until I finally got a hold of a Fuji factory shop manual and there it was. One engine came from a vehicle with a manual transmission and the other from a vehicle with a automatic transmission. The engine from the car with the automatic transmission had hyd lifters and a had a different cam grind that raised the torque about 200 rpm higher on the curve chart, this was the one that had the performance, subsequent conversion have confirmed this feature, in fact some of the "aftermarket" re-grinds are very close to the one used on the hyd lifter set up.

Tony


Tony,
When I got the engine from Larry Johnson it had the Greg "Vallaish" conversion on it.Ceramic coated piston tops,teflon skirts,and a reground cam.It ran for about 10 hrs and the ceramics came off and ruined the engine.
When I rebuilt the engine I put a original 100hp cam that I had on hand. and replaced the hyd. lifters with solid. I have about 5-8 hrs on the engine before the fuel pump decieded to take a dump and put me down. I learned real quick what was ment about high wind and down wind. Was not nice!
I gave the ground cam to James O'Neal of Paint Rock, Al. for use in his machine.
 

automan1223

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Oriental, North Carolina
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Not a model "T"..

Not a model "T"..

Ed,

Do not want to disagree with you but I think you are missing the boat with what is out there in the way of the EJ series EFI subaru engines. Sure back in the day the EA 81 sure beat a vw or drone mac engine or early rotax...but I think the extra trouble required to hot rod a 81 till its a performer is not worth it.

My reasons are that the 81 is just not that strong an engine to begin with.. For starters even with a cam and intake the heads are a handicap. Sure you can get the hi po heads which rework valve locations but they are rare and cores are getting rarer. Second a direct drive engine is anemic performer even for a light pilot. With a redrive its better but not going to blow your doors off. And on a hot day it might not fly at all....

My opinion, the EJ 2.2. or 2.5 could be setup stock as a direct drive and I think with the right prop, could be a good solution for a to the aging ea 81. As it is the early EJ engines are 22 years old now and the EA even older than that.

Not to be disrespectful in any way but I think the EA 81 best be left alone unless one has a large number of good cores and parts. Even updating to EFI proved interesting because the donor cars are rare. Of course aftermarket can supply almost anything for a fee.


Yes the 81 is a cute little boxer engine but that is about where is stops for anyone over 180 lbs.

J
 

dinoa

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Joined
Apr 3, 2007
Messages
765
Location
florida
Ed,

What's the differance in performance between an EA81 with 60" Warp drive prop at 2600 rpm and a Tenessee 52" X 26" at 3500rpm?

Dino
 

earthbnd misfit

Biggles
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465
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Swan Hill Victoria
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Paramotor. 30m2 wing, had benson gyro
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Thanks Mike.
I have a EA81 Turbo. Great engine, bullet proof. Hand cranked, no problem.
Needed a manual for a long time.:D
 

helicopter ed

helicopter ed
Joined
Nov 8, 2010
Messages
210
Location
Hamilton, Oh
Aircraft
Gyrochopper1/Air Comm. single/AC side by side/AC tandem. All powered by Subaru EA-81 100 HP
Total Flight Time
4000+ all rotorcraft.
Ed,

Do not want to disagree with you but I think you are missing the boat with what is out there in the way of the EJ series EFI subaru engines. Sure back in the day the EA 81 sure beat a vw or drone mac engine or early rotax...but I think the extra trouble required to hot rod a 81 till its a performer is not worth it.

My reasons are that the 81 is just not that strong an engine to begin with.. For starters even with a cam and intake the heads are a handicap. Sure you can get the hi po heads which rework valve locations but they are rare and cores are getting rarer. Second a direct drive engine is anemic performer even for a light pilot. With a redrive its better but not going to blow your doors off. And on a hot day it might not fly at all....

My opinion, the EJ 2.2. or 2.5 could be setup stock as a direct drive and I think with the right prop, could be a good solution for a to the aging ea 81. As it is the early EJ engines are 22 years old now and the EA even older than that.

Not to be disrespectful in any way but I think the EA 81 best be left alone unless one has a large number of good cores and parts. Even updating to EFI proved interesting because the donor cars are rare. Of course aftermarket can supply almost anything for a fee.


Yes the 81 is a cute little boxer engine but that is about where is stops for anyone over 180 lbs.

J
All due respect to you Jon, My formula for success was disregarded by you, you failed to get the true story. If you tried the EA-81 without my formula to the letter, I admit it was less then you expected. How can you discount 25 years of doing it right and 4000+ hours and no cost to fix anything, Why would you ever need extra cores? You didn't read my post.
Again due respect, that is what is the main problem with RF, low hour experts discounting experience, what you low time guys say dosen't amount to a hill of beans, Any time you want a good show with a 2600 RPM EA-81, I be ready and waiting to make a beliver out of a skeptic. Tony started the success with the EA-81, I kept tweeking his brain child. I repeat what I org. said. A good rotor is paramount, and pilot weigh 180, Thanks Jon for letting me tell you, that you don't know a thing about the most simple best engine yet. Its bullet proof, has proved it to me ever since I joined Tony back in 1987, 25 years now...
 

helicopter ed

helicopter ed
Joined
Nov 8, 2010
Messages
210
Location
Hamilton, Oh
Aircraft
Gyrochopper1/Air Comm. single/AC side by side/AC tandem. All powered by Subaru EA-81 100 HP
Total Flight Time
4000+ all rotorcraft.
Ed,

What's the differance in performance between an EA81 with 60" Warp drive prop at 2600 rpm and a Tenessee 52" X 26" at 3500rpm?

Dino
Thanks for asking, The 52 X 26 is what we all used at first, same as VW and the Mac. It is a club and not near as effceient as a thin sharp lead edge longer 60" Warp 2 blade prop. The difference is really noticable. I put the 52" back on every once in a while just for old time sake, it turns 3400 and makes lots of noise, use 25% more fuel, and acts like Jon talked about...
 

helicopter ed

helicopter ed
Joined
Nov 8, 2010
Messages
210
Location
Hamilton, Oh
Aircraft
Gyrochopper1/Air Comm. single/AC side by side/AC tandem. All powered by Subaru EA-81 100 HP
Total Flight Time
4000+ all rotorcraft.
Ed
I have a 83 ea-81 that I intend to have for a long time. Just getting started on ordering new seals and bearings.

How did you set up the holley carb on Dougs gyro?

Thanks

Mike
Thanks for asking. I always use the stock intake manifold, I have a machine shop make a 3/4'' thick adapter from the org carb holes, to any carb you use. I used the 77 Pinto Holly on Dougs set up, he has not stopped smiling since. You can use the stock EA-81 carb, it works great too...
 

dinoa

Junior Member
Joined
Apr 3, 2007
Messages
765
Location
florida
Ed,

You're still providing the answers after so many years.

I'm thinking of changing to a two blade 60" Warp Drive to check out the differance. Is the stiff carbon prop compatible with the EA81 crank. I heard VWs were breaking cranks with two blade Warps.

At 35hrs after installing my EA81, crankshaft end play measured at 0.002" as I wanted to monitor if the propellor thrust loads were causing excessive wear on the journal bearings.

At each oil change very fine brass dust could be found in oil samples held up to bright light.

70 flight hours later the endplay had increased to 0.0035" and the fine dust is still there. My Haynes Subaru maunual lists standard endplay at 0.0016-0.0054" with a service limit of 0.0118".

Is the increase in endplay a result of the bearings bedding themselves in to the propellor thrust loads or is it a sign of impending bearing failure? Otherwise the engine has been running smoothly with no rumbling or other unusual noises, oil pressure steady at 60 psi, low oil temperatures, no crankcase smoke. Except for the brass particles the oil comes out normally used with no burning or unusual smells.

Dino
 

helicopter ed

helicopter ed
Joined
Nov 8, 2010
Messages
210
Location
Hamilton, Oh
Aircraft
Gyrochopper1/Air Comm. single/AC side by side/AC tandem. All powered by Subaru EA-81 100 HP
Total Flight Time
4000+ all rotorcraft.
Ed,

You're still providing the answers after so many years.

I'm thinking of changing to a two blade 60" Warp Drive to check out the differance. Is the stiff carbon prop compatible with the EA81 crank. I heard VWs were breaking cranks with two blade Warps.

At 35hrs after installing my EA81, crankshaft end play measured at 0.002" as I wanted to monitor if the propellor thrust loads were causing excessive wear on the journal bearings.

At each oil change very fine brass dust could be found in oil samples held up to bright light.

70 flight hours later the endplay had increased to 0.0035" and the fine dust is still there. My Haynes Subaru maunual lists standard endplay at 0.0016-0.0054" with a service limit of 0.0118".

Is the increase in endplay a result of the bearings bedding themselves in to the propellor thrust loads or is it a sign of impending bearing failure? Otherwise the engine has been running smoothly with no rumbling or other unusual noises, oil pressure steady at 60 psi, low oil temperatures, no crankcase smoke. Except for the brass particles the oil comes out normally used with no burning or unusual smells.

Dino
Thanks for asking Dino, here is a good rule of thumb, most things we worry about never happen. The VW crank breaks were always the pully end of crank, we who ran prop hub on flywheel end, never knew of that end failing. Now, on the EA-81, rest eazy, the crank is bullet proof. I have seen high milage engines with .012 You have a long way to go yet. You will never wear that down unless you add sand to your oil. The 60" prop will not hurt your crank. Use the best 15-40 HD diesel service oil & 25% Mistery Marvel, [if available in Greece], and you will never wear out any engine that is specs...
 
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