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08-18-2015, 12:29 PM
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Join Date: Oct 2007
Location: Novato, CA
Posts: 319
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This would be my choice for an alternative motor!
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RV-6 panel is fine. Just... fine.
2019 VAF dues paid!
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08-18-2015, 04:42 PM
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Join Date: Jun 2007
Location: palm coast fl.
Posts: 945
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Alternative
Some how I think the Electric Motors are going to be the " Go To " alternative
power plant in the very near future . Might not be a cross country motor , but
great afternoon "1 hour Fix" plane motor . Rv3 ????
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Rv8
N 666 TA
First Flight 2-3-2015 🚀
2017 donation paid
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08-18-2015, 10:02 PM
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Join Date: Dec 2010
Location: Vacaville, CA
Posts: 167
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Fuel consumption
My Subaru is very economical for local sight seeing flights. I burn 3 GPH at 100kts on autogas. I took a local Cherokee pilot for a 30 min flight over the local hills and burned 1.8 gallons. He was impressed that our flight cost about 6 dollars in fuel!
-Andy
RV-9A
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Andy Simpkinson
RV-9a Subaru engine.
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08-19-2015, 06:39 AM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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Andy has one of the higher time Egg conversions now, showing that a number of these are still working well years later.
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08-19-2015, 07:38 AM
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Join Date: Sep 2007
Location: Central IL
Posts: 5,516
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Quote:
Originally Posted by rv6ejguy
Andy has one of the higher time Egg conversions now, showing that a number of these are still working well years later.
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I thought one core root cause for the Subie installation failures was the gearbox (PSRU) - what does Andy have? And what is different about it to make it successful?
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Bill
RV-7
Lord Kelvin:
“I often say that when you can measure what you are speaking about,
and express it in numbers, you know something about it; but when you
cannot measure it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind.”
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08-19-2015, 08:46 AM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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The original 4 cylinder engines with Gen 1 gearbox were overall quite reliable. A number of those, including one of the highest time ones is that configuration. The problem was they were only putting out about 125hp at best so performance was a bit weak.
Problems started showing up when the more powerful six cylinder engines came along. The Gen 1 box was not up to the task so the Gen 2 came out and it wasn't so good. Then the Gen 3 was designed which was much stronger. Some people have had good service from the Gen 3s, others have had weld breakages, bearing issues, oil leaks and spline wear or breakage issues. A dual mass flywheel came out on the later 6 cylinder setups which may be better than the solid flywheel used earlier from a TV POV however I know of several solid flywheel sixes with pretty high time and no issues. The solid flywheel setup, Gen 1 and Gen 2 boxes were declared unairworthy by Eggenfellner a few years back now. The welded areas inside the gearbox are hard to inspect and a bit worrisome. Welding in these spots was not a good idea IMO.
There are several known problems with the Gen 3. Alignment of the gearbox on the engine is critical and often not done correctly. Failures due to poor alignment maybe should not be blamed on the GB. There were no dowels used on the GB to properly facilitate this like you'd find in a properly engineered piece but there is a procedure and tool to accomplish this task that works well.
Type of lube used on the spline shaft is critical. The shaft does not engage the internal spline fully as designed, another puzzling oversight.
The Gen 3 box demands at least yearly inspections, especially of the spline shaft and lubrication state. I don't consider it as reliable or trouble free as the Marcotte or Autoflight boxes but it gives decent service for the most part when maintained and inspected properly.
The gearbox issues are known by the users on the Subenews group which is dedicated to highlight problems and experiences with the Eggenfellner packages, find solutions and fixes for them and keep the group flying safely. They distribute inspection and maintenance information which is a very valuable asset to all involved.
Last edited by rv6ejguy : 08-20-2015 at 09:49 AM.
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08-19-2015, 01:38 PM
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Join Date: Jan 2005
Location: Sherwood, Oregon
Posts: 981
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Subie H.P. ?
Quote:
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The original 4 cylinder engines with Gen 1 gearbox were overall quite reliable. A number of those, including one of the highest time ones is that configuration. The problem was they were only putting out about 125hp at best so performance was a bit weak.
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Hi Ross,
Always happy to see your insightful comments. The one above begs the question: Why does an engine Subaru rated at 160 HP at the flywheel, I presume, only put out 125 hp in an RV? Surely the redrive isn't sucking all that power up? The first RV equipped with an EGG could only get around 140kts. Guess that should have been a tipoff. I bailed luckily enough on that whole scene when I criticized the business practices of same.
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Jerry Cochran
Sherwood, Oregon
RV-7a 707DD Bot from David Domeier 12/01/11
Lycoming IO-360 Catto 3 blade Panel upgrade in progress
RV6a 18XP 1st flite 03/21/07 sold to Dale Walter 10/22/2011
Superior IO-360, Hartzell Blended, GRT/Dynon
Happily "autopaying" DR
"Suppose you were an idiot, and suppose you were a member of Congress; but I repeat myself."
Mark Twain
Last edited by Jerry Cochran : 08-19-2015 at 01:42 PM.
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08-19-2015, 04:42 PM
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Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
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Quote:
Originally Posted by Jerry Cochran
Hi Ross,
Always happy to see your insightful comments. The one above begs the question: Why does an engine Subaru rated at 160 HP at the flywheel, I presume, only put out 125 hp in an RV? Surely the redrive isn't sucking all that power up? The first RV equipped with an EGG could only get around 140kts. Guess that should have been a tipoff. I bailed luckily enough on that whole scene when I criticized the business practices of same.
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Was mainly due to changes to the intake manifold and the fact that the engine was not geared for peak hp rpm.
A supercharged 2.5 was introduced to help find some more power and this surprising worked pretty well for many users. It simply added an Eaton supercharger to the basic EJ25 engine and stock ECU.
Then there was the STi disaster. This took the EJ257 turbo engine, removed the turbo, added an Eaton blower and complicated/unreliable boost control system instead and tried to use the very complicated stock ECU for this engine. I believe every single one suffered either a forced landing or scared the pilot enough times with ECU issues to abandon the original setup.
The E6 and H6 engines (EZ30) were reasonably reliable in most cases but quite porky. They were down on power again from stock due to restrictive intake and exhaust systems again, plus mods to the VVT system, probably putting out around 170-180hp.
A few EZ30 turbos made it to market. Most I know of broke pistons but I have a customer in Norway with one having around 400 hours (never touched internally) on it now in an RV7, 170 KTAS on 9.25 gal./ hr. The turbos were not matched properly and they had a funky boost control system because of that but they worked ok at medium altitudes.
At the last was a handful of EZ36 engines, probably putting out close to 200hp but almost all of them blew up (piston failures) in fairly short order due to improper mapping of the ECUs.
Most customers got very good, fresh used engines, others got some pretty bagged out ones full of sludge or rust. The later engines were never even opened up for inspection it appears.
IMO the EJ257 STi 4 cylinder engine had the most potential being light enough to compete with the Lycoming and serious hp potential. The stock ECU and the supercharger were the big mistakes here. I was involved consulting on two RV7s with STi engines converted back to turbo with properly matched Garretts, intercooler and our programmable SDS ECU. These aircraft were super fast- Vne in level flight at low boost and gave decent fuel economy as well. One is still flying up north of me and so far, pretty reliable.
Done right, these are probably the best base engines to start with for an RV conversion. New short blocks are available for around $2800 and you can fit SOHC heads to save about 15 pounds. Good used, complete EJ257s go for around $3500-$4500 usually. Rated at around 300hp stock, depending on year so not working very hard to put out 200hp for takeoff and 150 for cruise.
One thing we've found is that these engines generally don't like a steady diet of 100LL, usually leading to valve problems. That can be an issue on extended cross countries where it's hard to find unleaded fuel enroute.
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08-20-2015, 09:50 PM
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Join Date: Dec 2010
Location: Vacaville, CA
Posts: 167
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Subaru gearboxes
I have the Gen3 gearbox and dual mass flywheel. IMO the dual mass flywheel is the single most important update for any gearbox. It serves as a torsional damper, reducing the impulse from the engine by probably an order of magnitude. There have been no failures of this combination (as far as I've been able to determine). It's also lighter than the solid flywheel.
With the gear ratio of 2.02 it allows all the power potential of the engine. The performance of the engine is comparable to an O-320 with fixed pitch prop. The weight is comparable to an O-360. The advantage of this engine are: ease of starting and operating, ease and cost of maintaining, smoothness of operation and overall fuel economy. Disadvantages are: power to weight, possible future failures that are unknown due to small numbers operating, resale value, might be hard to maintain for a non do-it-yourselfer.
The support of the community on the internet is the only thing that has made this engine option viable. We have chased down dozens of problems and found fixes for them.
Performance in an RV-9 is pretty good. My top speed is 173KTAS. I can climb to 9500 feet in 10 minutes solo. That climb is with reduced power at 110 KIAS and burning under 10GPH. 150KTAS cruise is at 7GPH low altitude and 6GPH at high altitude.
-Andy
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Andy Simpkinson
RV-9a Subaru engine.
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08-21-2015, 08:22 AM
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Join Date: May 2005
Location: Rochester Hills, MI
Posts: 879
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Quote:
Originally Posted by DanH
As noted previously, you don't have a dual mass; Jan removed one of the masses, while retaining the springs. It was a very clever use of OEM parts.
Nor do you have a damper.
I'm sorry, but advancing the art will require at least some fundamental understanding.
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Yeah, you can split hairs on the terminology, but the combination works pretty well as Andy noted. I think he understands, despite the questionable naming. His assessment is spot on.
We should probably be calling it something like a '2 piece spring separated' flywheel. The springs soften the pulses, friction provides a bit of damping, so it does act a bit as a torsional damper - apparently enough to get the job done (so far anyway).
Instead of looking for the negatives, why not look for the positives? That is what advances the art.
I have 400 hours on my H6-Gen3 and the insides of my GB still look brand new, and my (lubricated) spline shaft shows no signs of wear.
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Dennis Glaeser CFII
Rochester Hills, MI
RV-7A - Eggenfellner H6, GRT Sport ES, EIS4000, 300XL, SL30, TT Gemini, PMA6000, AK950L, GT320,
uAvionixEcho ADSB in/out with GRT Safe Fly GPS
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