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12-15-2009, 06:50 AM
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Join Date: Jan 2005
Location: SC
Posts: 12,887
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Alternative Engine Marketing
Let me start this thread by asking the moderators to delete any post that bashes alternative engines. That horse has been pounded into dust and we don?t need to go there.
I would like to ask what it would take for you to install an alternative ?Packaged? engine in your plane.
Are you looking at price, weight, fuel consumption, power, reliability, what exactly?
Don?t just answer with reliability and weight. Tell us what your measure of ?reliability? is and what is acceptable weight to you. i.e.: It must run to a 5000 hour TBO like the turbine I fly at work and it is OK to weigh 50 pounds more than a comparable Lycoming.
In my case, it is the three legged stool. Reliability, weight, and price. I enjoy building but I also enjoy flying. Once it is done, I don?t want to have to spend three hours of maintenance for every hour of flight. If I wanted that, I would have built a helicopter.
The installed weight should be the same or less than a comparable Lycoming. I can always add weight, if needed, but it is difficult to remove weight.
Price is something that drives me crazy with the alterative engine builders. Whenever a new engine package hits the market they always seem to be priced more than a comparable Lycoming. It seems to me they should be about half the price, at least at first. This will get a number of engines out there and once they prove their value, then they can raise the price.
__________________
Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
SC86 - Easley, SC
www.repucci.com/bill/baf.html
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12-15-2009, 07:48 AM
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Join Date: Feb 2006
Posts: 305
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Proven Reliability
Let me start by saying that I have a real interest in engines, and applaud those that venture into alternative engine development. I used to play with small British "A" series engines, with a goal not of reliability but horsepower so am not entirely unfamiliar with engine design adn development although in a very amatuer and low budget way.
For an aircraft, the choice of an "alternative" engine must always be measured against what it is an alternative to - in our case, a Lycoming or Lycoming clone.
So, for those who are not simply looking to be "experimental" in the best traditions of our hobby and so not driven simply by the desire to see what is possible, the benchmark is a Lycoming.
Someone on this list described the Lycoming as a "Lycosaurus" in the sense of being excellently adapted to its purpose (rather than simply being ancient), so more like a crocodile. I think that is right. A Lycoming has had decades of development, proven and recorded service history within the discipline of a regulatory regime that requires issues to be indentified, published and parts with a proven provenance. And all of this with the primary imperative of safety and reliability.
The result is an expensive, conservatively designed and reliable aircraft engine. It is a known quantity and so has a predictable value at all stages of its life cycle. Parts are available and easily sourced. If one vendor goes under, there are others.
For me, proven reliability is key and the primary measure against which alternatives will be judged. It is trite to say that it is one thing to play with engines that may blow up in a car, and another in aircraft. We have responsibilities to ourselves, our sport, our families and those on the ground. Not at all to say that considering alterntives is in any way irresponsible, but it is a serious matter that needs a thoughtful and careful appoach.
Other factors, like price, vendor confidence, resale value, parts availability, repairability, all weigh in the mix (and likely to the disadvantage of present alternatives).
Technological advances and maximum power are not priorities for me, although having said that the engine I chose is a Superior with roller rockers, fuel injection and one electronic ignition, one mag. Technological advances that actually improve performance if available without compromising the basic requirement of reliability certainly have appeal.
For me, an alternative (to a Lycoming) engine is not out of the question, but given what I consider important I anm not aware of any alternative that at this point in time comes close to a Lycoming or clone.
Bill Brooks
Ottawa, Canada
RV-6A finishing kit
For me, an alte
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12-15-2009, 08:18 AM
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Join Date: Jul 2009
Location: Wilsonville, OR
Posts: 453
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As someone who is traditionally not a big fan of alternative engines, maybe because of ignorance and some experience with an Egg., let me ask this. What is the downside of installing a traditional Lycoming? I'm building an RV-7 and considering all options. I've lost an oil line in a C-150 once and had to make a forced landing, but that wasn't the fault of the engine (mechanic overtighened a hose clamp which put a hole in it). I'm looking at an IO-360 which is pretty fuel efficient, reliable, proven, not terribly expensive to operate and supported long-term by the manufacturer. I know the initial investment is indeed more costly than most alternative engines. What other negatives are there for a Lycoming? I definetly support research and improvement, that's why we are experimental. Not to mention we don't know how long the EPA will let us have 100LL.
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Trevor Conroy CFII, MEI
Airbus Pilot
N781TD
RV-7
First Flight - April 12, 2015
Construction Log
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12-15-2009, 08:42 AM
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Join Date: Jan 2005
Location: Near Scipio, in Southern Indiana
Posts: 1,779
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Deciding on an alternative would be easy for me. Just give me ONE big plus, and no negatives, and I'd switch in a heartbeat. Whether it is TBO, fuel burn, weight, real reliability, cost, whatever, if there are no negative (like lower TBO, lower resale, or higher weight) I would be happy to switch. Not only have I not been able to find an alternative without big negatives, I haven't found one with significant pluses. All things considered, the Lyc is way ahead IMHO. And I started my build with the idea of using a Subaru engine!
Bob Kelly
__________________
Bob Kelly, Scipio, Indiana
Tech Counselor
Founder, Eagle's Nest Projects
President, AviationNation, Inc
RV-9A N908BL, Flying
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12-15-2009, 09:19 AM
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Join Date: Jan 2005
Location: Martinsville, IN
Posts: 2,326
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It's really a simple equation. It has to have the same reliability as a Lycoming but cost less to acquire and maintain. No one is going to pay more for an alternative at double the reliability because the current reliability is sufficient. And only a few will spend less for less reliability because the risk equation doesn't make sense.
In essence, I want to spend less and not pay with my life for doing so.
__________________
Randy Pflanzer
Greenwood, IN
www.pflanzer-aviation.com
Paid through 2043!
Lund fishing Boat, 2017, GONE FISHING
RV-12 - Completed 2014, Sold
427 Shelby Cobra - Completed 2012, Sold
F1 EVO - partially completed, Sold
F1 Rocket - Completed 2005, Sold
RV-7A - Partially completed, Sold
RV-6 - Completed 2000, Sold
Long-EZ - Completed 1987, Sold
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12-15-2009, 09:35 AM
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Join Date: Oct 2008
Location: Schaumburg, IL
Posts: 2,053
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I really considered an EGG. I think the concept is great. If someone is really interested in making one work, I say go for it. I decided on a Lyclone as it gave me the ability to have a tried and true design, still with a little bit of an "experimental" flavor to it.
I'll bet you someone someday soon, will figure out how to make an electric powerplant fit in an RV and will are start getting on or throwing stones at that bandwagon.
__________________
Tony Phillips
N524AP, RV 9 (tail wheel)
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12-15-2009, 09:42 AM
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Join Date: Oct 2006
Location: Garden City, Tx
Posts: 5,145
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The gearbox is what scares me. I know we have many geared engines in service from the major companies, and they all have millions of hours (aka reliability) of experience to learn how to build them. A new shop building a new gearbox worries me - and we've all seen the heartburn that Eggenfelner went through with his gearboxes.
Avoiding a gearbox means running at prop RPM, which means high displacement, which means either running a Lyclone (which is becoming the new definition of "alternative" with a lot of people) or a turbodiesel. The turbodiesel is very attractive to me for several reasons, but there is not currently anyone offering a REASONABLE package on the experimental market.
I can see paying some additional margin (within reason) for an alternative engine, whether that's money to purchase it or time to modify the installation. I can deal with that in order to gain something else, such as the ability to run on fuels other than 100LL, or to have turbonormalizing, or to have quick/easy/cheap rebuilds at TBO.
Speaking of TBO - [RANT ON] What the heck was Thielert thinking with a TBR??? [/RANT]
__________________
Greg Niehues - SEL, IFR, Repairman Cert.
Garden City, TX VAF 2020 dues paid 
N16GN flying 700 hrs and counting; IO360, SDS, WWRV200, Dynon HDX, 430W
Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now.
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12-15-2009, 10:03 AM
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Join Date: Aug 2007
Location: S21, Oregon
Posts: 161
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Efficiency
Would be a key factor for me. I was really eyeing the DeltaHawk, and I hope that they are successful, but I started my build knowing quite well that they may not have something on the market by the time I was ready for it. Initially, their engine price was comparable, weight was comparable, and the fuel flow was lower (with better future availability), and speed potential at altitude is higher. But now that they're quoting a $62,000 firewall forward price (minus prop), that's the final nail in the coffin for me. I like the idea of direct drive and no valvetrain- it SEEMS it should be VERY reliable, but only time will tell, and at $62k, I think it's going to be a long time before there's a significant number in the field 
__________________
Kelly
RV-7 empennage done, wings done, fuselage to QB stage.
1973 Maule M4-220C flying
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12-15-2009, 11:23 AM
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Join Date: May 2008
Location: Houston, Alaska
Posts: 292
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Quote:
Originally Posted by TCONROY
As someone who is traditionally not a big fan of alternative engines, maybe because of ignorance and some experience with an Egg., let me ask this. What is the downside of installing a traditional Lycoming?
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A number of things really:
1. The fuel system isn't hydraulically correct. The auto market went to tank mounted pusher pumps long ago and we haven't had a lick of problems with vapor lock since.
2. They are wildly inefficient. Static timing a 540 cubic inch engine to get 260 HP on 100 octane fuel isn't that great when it would be trivial to make more HP on an engine half the size using 93 octane if it was water cooled and could rev.
3. The size of the engine combined with the thermal expansion causes cracks and other things to happen over time. Some engines are worse than others.
4. A liquid cooled engine doesn't have to deal with a huge temp delta meaning that the machined parts have WAY tighter tolerances which results in better wear.
5. A liquid cooled engine is far better for winter operation since you get a real heater, and you can use a freeze plug heater to prewarm the engine. Plug it in like you car, start it up and your good to go.
6. The lycoming injection system is great in that it doesn't require electricity, but hot starts are a pain because of vapor lock. High pressure fuel injection is far better.
7. Liquid cooled engines can be run on the ground without fear of cooling if they are designed correctly, Also, there is no worry about shock cooling the engine.
8. Playing with the cowl flaps, mixture, climb speed and other things to manage cyl temps wouldn't be a factor on a liquid cooled engine.
There are more but in a nutshell, the difference between a liquid cooled and air cooled engine is pretty huge. Look at any industry where there are both liquid and air cooled engines and you will find that the performance and reliability are tremendously better for the liquid engines. Comparing a lycoming to a modern auto conversion is like comparing a VW bug engine to a 4cyl honda.
All these things said, I bought a lycoming. Here is why:
1. I couldn't find a gearbox that correctly dealt with vibration that was well proven. Designing a gearbox is extremely difficult to do. Those that don't know exactly what the resonance rpm is with a given engine and prop combo didn't do it correctly. Saying that you have bushings, clutches, couplers, or whatever doesn't cut it. EVERYTHING vibrates and has a resonance frequency, and if you operate in that range, then it will come apart sooner or later.
Also, saying that the gearbox has 2000 hours on it doesn't mean anything if you don't know where it resonates at. One guy could fly it around at 2620rpm for decades, and the next guy could fly it at 1721rpm for 2 hours and have it fail.
2. Nobody has a good package that has extensive testing on a specific prop, gearbox, and engine. Many test the engine, gearbox, and prop separately which doesn't make sense. Most PSRU vendors say you can run any prop and engine you want as long as it bolts up, which is bogus. Egg probably tests the combo more than anyone else, and he has his fair share of PSRU failures as well.
3. The prop choices stink. I want a real hydraulic constant speed. I think I can run this on a geared drives PSRU, but that is a heavy setup with the v8, and from what I understand the subaru version wasn't tested on a subaru, rather an adapter that was bolted to a v8. Even then, I want to know the vibration characteristics of the prop, engine, and PSRU as a unit. When I emailed geared drives, I was told that it doesn't vibrate, which is wrong.
4. There aren't that many options for fuel system controllers that have redundancy. I know that Ross's units are reliable, and that adding the fault tolerance would likely add more points of failure, but it does make it tough to sell to an airplane guy that is used to having redundancy in this area.
At the end of the day it really came down to the PSRU. If you go look at those that take an engineering approach to the PSRU (EPI) then you will see that it's not trivial to build one of these and that for small engines it is usually cost and weight prohibitive. It seems that those that are cranking out smaller PSRU units are ignoring or ignorant of the vibration problems.
On the other hand, the lycoming is such a 50's way of doing things that has it's own problems.
What I would really love is a 300 cubic inch 6 cyl rotax. If they can make a 82.5ci engine produce 100hp on 87 octane, then imagine what they could do with 300ci. I also like their water cooled heads, air cooled cyl, and oil cooled case design. It makes the cooling system much smaller while keeping most of the benefits to liquid cooling.
It's unfortunate that the exchange rate (taxes though inflation) has this engine over $26k now. With the level of spending our government has, I suspect it will only get worse.
schu
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12-15-2009, 11:41 AM
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Join Date: Jan 2005
Location: Roanoke, VA
Posts: 306
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Demonstrated reliability
Reliability is number one for me, and the reliability needs to be demonstrated. I would want to see a history of reliability on a number of airframes with greater than 500 hours of trouble-free operation without the need for significant upgrades or modifications to make it work.
I don't want to have any part in an alternative engine experiment. I've made about 60 off-field landings in sailplanes, and have learned enough to know that I want to avoid that risk in airplanes as much as possible.
Of course, the weight and horsepower must be approprate for the aircraft being considered, there needs to be at least one compelling advantage over a Lycoming, and the price should be reasonable.
__________________
Dave Cole RV-7 N97DC reserved
dave.cole@cox.net
Started SB April 2004
Hope to fly in 2011
Last edited by Dave Cole : 12-15-2009 at 11:43 AM.
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