EA-81 information sharing

CLS447

Platinum Member
Joined
Oct 30, 2003
Messages
6,324
Location
Reading, PA
Aircraft
Air Command 503 & Air Command SxS /EJ2.5
Total Flight Time
Aprox 400 gyro
Jon, first let me get a handle on the setup that you are using.

Standard single carb EA-81 engine?

RFI redrive ratio?

60" 3 blade Warp Drive prop ....pitch??

Max RPM at this pitch setting?

Stock Subaru intake?

Any other engine mods?

I'll stop there for now. Thanks


Have you seen pics of my Joe Souza 81?
 
Engine Details

Engine Details

Yes it is a two-barrel carb, I am not sure of the make right now. But it starts easily and does not hesitate in any mode. Helicopter Ed sold it and he had an adapter plate to mate to the stock intake.

I think the redrive is a 2.1.

64” Warp drive prop at about 10 degrees. Length chosen because that is what would fit on the first airframe I built.

Wide open during climb is 4800 rpm.

Standard coil with stock pointless ignition.

The exhaust I have now is just two pieces of stainless steel flexible pipe about 5 feet on each side. It is working very well. I had a Joe Souza pipe for short time but it cracked.

Heads have been shaved .10 mainly to make sure they were flat.

Climb performance is OK. Not breath taking. I am trying to lose more weight myself. I lost 60 pounds and that made a huge difference.


I have seen your pics but it has been awhile and cannot remember the details.
 
Souza exhaust

Souza exhaust

Since you brought it up, let's start with exhausts. The first pipes I tried on my 81 were purchased from Ed A. I believe. They were short straight pipes that I first used. Very simple, but loud. I also heard that short straight pipes could lead to burning of the exhaust valves. I do not know if there is any truth to this statement. I had heard good things about the Souza exhaust, except the price. After talking with Joe, he said he would sell me the parts and I would do the welding myself. For $125 he said he would send me all the parts for the 6" round can and the new oval can.

The round can got lost in the mail and I decided to build the oval can exhaust myself without the confusion of cross country interpretations. I am also having cracking problems, but continue to try because the exhaust is so quiet. The material that forms the oval can around the oval endcaps is quite thin and the cracks are occurring at the edges of the weld bead.

My second hired welder told me that stainless must be purged with argon to prevent the chromium from becoming brittle. I take great faith in his work as he does alot of stainless welding.

Which exhaust can did you buy, how much was it, and where was your cracking occurring?

When my last crack occurred, I was doing temperature testing. To continue testing I reinstalled the short straight pipes. I found that I gained 100rpm and the temperatures dropped due to the fact the exhaust was now nowhere near my radiator.

I am now relocating the radiator because I really want to use this exhaust. I have had a patch plate welded over the seam in hopes of eliminating the problem.

Here is a picture of the repaired exhaust with the radiator relocated to the back side of the vertical motor mount support. It used to be on the front side of that same support, which put the exhaust only inches away and blocking the top half of the radiator. This was in my opinion raising my coolant temps to unacceptable levels.

With your response to this subject I would then like to move onto the subject of the radiator.

Any input you or anyone else can add to the exhaust subject would be appreciated.
 

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i have a ea 81
13 deg pitch
62 inch prop
5400 rpms
350 lbs of thrust at 4800 rpm (ran out of scale)

jonvee whats your all up wieght
 
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EA-81 exhaust

EA-81 exhaust

The Souza pipes were just straight pipes that were criss-crossed under the engine and welded together. They were cracking in the elbow. I think the engine grows during normal heating and the exhaust made of thin stainless cannot take the flexing when welded together under the engine. I re-used the short pieces that bolt to the engine and purchased stainless flex pipe that slipped over it and then brazed it together.
 
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Ben,

You are making some real HP to be able to have that much pitch and get over 5k RPM. All up weight is about 750lbs.
 
Pipes

Pipes

Interestingly, those sound like the pipes Ben has. What diameter are yours Jon?

Ok, assuming your intake is stock, Did you trim off the unnecesary stuff off of it? Are you using the T-stat in the stock location & what temp?

Is your radiator custom or is it from an auto? Is it double row & where are the in & outs located?

What are your normal run temps?

Did you ever encounter carb ice?
 
Another area of interest..... Please tell me about your valve cover breathing system.

Also, what alternator & battery are you using?
 
jonvee,

what kind of rotorblades ya using and how long might they be and what speed is your rotor tach at climb and cruse?? jon vee thanks for your time
 
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Guys, have any of you looked at a aftermarker car muffler called a FlowMaster??? It looks alot like the Oval can Chris is running. I bet a Flowmaster would not crack and would do the trick as far as keeping it semi quiet. Also Flowmasters are high flow mufflers and wouldn't cause too much power loss. All the V-8 powered Ford Mustangs you hear running around with a deep throaty roar use a pair of Flowmasters.
 
The exhaust pipes are about 1 ¾.

I just plugged the holes in the intake. Stock T-stat position (185). Temp only goes above 185 after a couple of minutes of slow flight around 35 mph. Speeding up and drops back to 185.

The breather system has a PVC valve on the intake sucking from the left valve cover. The right valve cover gets clean air from the bottom of the carb air filter.

It is a standard VW Rabbit Rad (plastic tanks) with both outlets on the same side and end.

No carb ice. I think the stock intake has enough heat in it from the water to keep the butter fly clean.

I also purchased the Kubota alternator form Ed A. It is about 13 amps and I use a Black Panther battery. 500 CCA / 13lbs. It works well with the Electric pre-rotator. During test flights I would fly the length of the runway and turn around, pre-rotate and take off again. After about 8 pre-rotates the voltage will drop and the engine starts missing during pre-rotation. During normal flying this does not happen.

25 ft DW blades run about 355-360.
 
Anyone have an opinion re. putting a Super Trap motorcycle mufflers on an EA81? It has been suggested to me as a way to quiet down the EA81 with little or no effect on performance. Thanks. stuart
 
stuart said:
Anyone have an opinion re. putting a Super Trap motorcycle mufflers on an EA81? It has been suggested to me as a way to quiet down the EA81 with little or no effect on performance. Thanks. stuart

Richard "Catfish" Oxnam has a set on his gyro. You may want to email him and see how they have been working for him.
 

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That Catfish sure has a sweet machine, don't he?

Jon, What fuel pumps are you using?

What exactly are the spark plugs you like for the 81?

BTW Jon, I just visited your website for the first time. Very nicely done!

What is your fuel burn?
 
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I have single Facet electric pump. I dont have the exact sparkplug number but it is the Champion plug that is called for at the auto store.
 
Jon, which facet pump? What fuel pressure? Is it fused?

I might convert my KB-2 to CLT .... Any kits or plans to do this easily?

How about a closeup of your front wheel steering system?

Is that funny looking fitting in the stock 81 intake actually the PCV valve?

Can someone explain the PCV system to me again? Someone did a great job of it once on Norm's forum.

Jon Weis, I went to your website.... Still have not seen a pic of your gyro! Does it fly? Do you fly? What's up?
 
jonvee,
did you have taller teeter tower made for your dagon wings? if so how much higer then benson standard are they? and what hole on the hubbar are ya using for your teeter bolt and do ya have any stick shake ??? thanks for your time ben
 
Chris Jonathan Weis is still a student learning to fly gyros. He has a nice Aircommand tandem gyro that had been crashed and rebuilt just before he bought it. He is still working out the bugs from that crash and also the gyro is a tank and weights a ton not to mention Jon is a towering lumberjack of a guy and with Maxies fat butt in the seat training him, the gyro is running out of go go juice. :)

So jonathan is putting on a bigger engine looking for more power and will tinker and tinker and tinker till finally one day he can feel satisfied that the gyro is fine and can focus on training to fly it.

One day, maybe when my son is old enough to give Jonathan some lessons he will join us in the sky!
 
Nose Gear, Fuel Pump, PVC

Nose Gear, Fuel Pump, PVC

I have some pictures now that should help this discussion.

The Nose gear came from Larry Neal and it was from his Falcon fixed wing Ultralight. I think AC is peddling it now. The horn on top is made to have steering cables to the rudder pedals. I tried it but have never liked that type of setup. To sensitive for me and it was hard to make U-turns on the runway. A lot variables come into play with length of pedal arms and such. It now is free castoring and the tube is a shimmy damper.
 

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Fuel Pump

Fuel Pump

I think it is the 3lb. size of pump. It is on a circuit breaker. I have filter on the input and drain cock on the output. It is the lowest part of the system.
 

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