ECI IOX-320 Stroker!

[cjensen]

Originally Posted by RVbySDI

...I am sure the only individual interested in this dissertation is writing it so I will put an end to this. Should there be, however, anyone interested in commenting on my writings I would greatly welcome your opinions and/or thoughts.

hmmm...i think you'll find there are plenty of interested individuals from what you've written here. i'm right there with ya on choosing an engine. i lean this way one day, and the other the next. i am very interested in the -340 engine, and i'm also very interested in the Egg H-6. i have a production slot reserved with Egg, but have not made any sort of committment to it, other than a small insignificant refundable deposit. i also really like the innodyn turbine, but even though i have high hopes for this alternative, it may be too good to be reality.

watchin' and waitin' with ya!

[Joey]

Originally Posted by RVbySDI

If small bore engines are not so prone to running low octane fuel such as mogas tends to be, then what fundamental problems are there in placing smaller bore engines with appropriate configurations to produce adequate HP in our airplanes?

Propeller RPM is the main factor. A small-bore engine with more cylinders has to spin faster to produce the power we need. Since we are limited in how fast we can turn a propeller, that puts the small-bore at a disadvantage, as it would need a redrive.

Why are air cooled engines "better" than water cooled for aviation

Air cooling is lighter, cheaper, simpler, and more reliable than liquid cooling. By far, the lightest and most reliable radiators, hoses, water pumps, and coolant are the ones we don't install. It can't break or weigh down the plane if it's never installed in the first place.

(Has anyone noticed how many water cooled high performance airplanes were built during WWII that we revere even today)? What happened to the idea that water cooled engines would work well in the flight environment?

We started to use more horizontally opposed engines rather than radials. Liquid cooled engines allowed us to have nice slim pointy noses on our airplanes, but at a cost. The horizontally opposed engine is a good compromise since it is a lot narrower than a radial, but still allows us to use air cooling.

Some would argue that Eggenfelner's Subaru engines are more complex than the typical Lyclone installation, yet, so far, these engines seem to be performing quite well in the planes flying them.

There is no absolutely no question that a Subaru installation is more complex than a typical Lycoming installation. That isn't necessarily a bad thing; I don't mind a little complexity as long as it doesn't break all the time.

Why are they able to use a small boxer 2.5 L engine to produce the needed HP to fly our babies? Something seems to be working with them.

They use a redrive. It does work, for some of them. Is it better? I don't think so. Is it at least as good? We'll see... but I still don't think so.

We are convinced that the only solution to powering our birds is to stay with the "standard" aviation large bore Lyclone engines?

If you took an engineer that had never seen an airplane before and asked him to design a 180hp aircraft engine without being prejudiced towards any particular design, he would likely come up with something that looks an awful lot like an 0-360, with probably some sort of two-stroke diesel not far behind. Everything about an aircraft engine is a compromise. The current aircraft engines are a result of all those compromises being tested and experimented with for the past few decades.

Hmmmmm, I am seeing a pattern in my perusal of this subject that is bringing up a non-technical question that I also seem to always be asking. Why do all of these engines cost 2 or 3 times more than an engine costs for any other internal combustion application?

Economies of scale. If there were a market for a million recip engines a year, then you would have cheap aircraft engines. If you have a machine that costs a million bucks just to make pistons and you only sell one piston a year, how much are you going to have to sell that piston for to make money? What if you sold 10 million a year? That's the difference between your car engine and an airplane engine. Boat engines come in somewhere in between, and so does their price.

[RVbySDI]

Joey,
Thanks for the informative replies. I agree for the most part with everything you have said here. However, I do think that it should be possible to build a powerful lightweight engine that does not cost 1/4 to 1/3 of the overall cost of the entire airplane. I am wrestling with all of the afore mentioned ideas when trying to decide what to do for an engine in my RV9A. As of today, I still do not have an answer. Reading these forums helps a great deal in allowing me an opportunity to learn about what others are doing and thinking about their engine choices.

Hopefully I will come up with a compromise that will end up working best for me eventually.

RVBYSDI
Steve

[pierre smith]

Hi Steve,
I sold Agwagons and Agtrucks for a Cessna dealer in the mid seventies. By 1980 the prices had escalated from $35,000 or so to $100,000 and a Cessna Rep told us that ONE THIRD of the cost of the airplanes was product liability insurance!! I suspect the same is true for the engines,
Pierre

ps Buy a used 0-360 and rebuild it yourself to save a bundle.......trust me, if you can build the plane, you can build the engine. Another option is to buy a runout takeout and fly it for several years to around 2500 hours or more and overhaul it ONLY if it needs it. Many Lycs run almost to 3000 hours. My next door buddy has a Skyhawk with over 2800 hours and still runs strong and has high compression and low oil consumption too.

[Joey]

Originally Posted by RVbySDI

I do think that it should be possible to build a powerful lightweight engine that does not cost 1/4 to 1/3 of the overall cost of the entire airplane.

With the growing popularity of experimentals, we might be headed that direction. We already have a lot more options than we did even 5-10 years ago. I personally think you could do pretty well with finding a run-out 150hp O-320 and overhauling it yourself, perhaps with someone looking over your shoulder. This could be done fairly inexpensively and would run like a top on car gas.

On preview: Yeah, what pierre said. The last O-320 I pulled for overhaul had 3400 hours on it.

[RVbySDI]

Pierre and Joey,

I have been thinking about the idea of building an engine for a while. However I am interested in fuel injection instead of carburated engines. I would like to find an IO-3XX that perhaps I could rebuild. As I stated I am just not sure yet what I will be able to end up doing.

Thanks for the comments.
RVBYSDI
Steve

[Joey]

Do you any specific performance goals in mind? The factory RV-9a pulls off 180mph at 6gph with a carbed o-320... That's pretty freakin good in my book.

That kind of performance makes you wonder if the extra cash and weight of fuel injection and/or electronic ignition in this case would even be worth it.

Not trying to talk you out of it, of course. Just thinking out loud.

[RVbySDI]

Originally Posted by Joey

Do you any specific performance goals in mind? The factory RV-9a pulls off 180mph at 6gph with a carbed o-320... That's pretty freakin good in my book.

That kind of performance makes you wonder if the extra cash and weight of fuel injection and/or electronic ignition in this case would even be worth it.

Not trying to talk you out of it, of course. Just thinking out loud.

I agree that the RV9A should perform exceptionally no matter what engine is placed in it. However, my desires for what type-size engine to use are based on my ideas concerning utilizing efficient design and economics more than for extracting the most speed out of the airframe. I do not buy into the notion that using carbs and mags is a better fit for an airplane engine. True these are simpler systems. But they are not totally without their problems. If we wanted to always "stay with what works" we wouldn't be flying anyway. We would still be sitting on a horse riding to work and shoveling manure to avoid stepping in it. I fervantly believe in striving to improve things. I absolutely do not believe that carbed, magneto driven Lycosaurs are the best engine alternative to choose from just because that is the way it has always been done.

Ok, my desires for an engine:

1.) I do not want a carburetor on anything newer than a 1965 Ford Mustang because I think that component of engine operation can be more efficiently managed by fuel injection. It has been unrefutably proven over the past 50 or 60 years that fuel injection is a much more efficient means of providing fuel to an engine. I do not want to have to deal with carb icing for one but I also think fuel injection is much more efficient.

2.) Another aspect of the engine setup I desire is electronic ignition. Again, mainly for effieciency and managability of the engine. I believe in new technology, even if it takes the aviation industry 50 years to accept it.

3.) Of course weight is a primary concern. I have been going back and forth on whether it is worth putting a CS prop on the airframe or going with a FP cruise prop. I don't think this airplane "needs" a CS prop to perform and since the CS does weigh more I am leaning toward the FP. Just haven't made up my mind yet.

The weight issue has me looking at the differences between the IO-320 and the IO-360 (and now the IO-340). I have been informed there is a 12-15 lb. difference between the IO-320 and the IO-360. I am concerned about an aft CG if I go through with my plans to modify the baggage compartment as Norman Hunger has done to carry two sets of golf clubs (click here to see his mods). If I make the modification, the weight difference of the IO-360 would help with CG when the baggage area is loaded down.

4.) Fuel used is also important to me. Not only is 100LL getting more and more expensive to the point that I wonder how I will afford to put fuel in my airplane but it will also be going away in the near future. I do not want to have to concern myself with figuring out what to do as a replacement. I like auto fuel. I think it is a perfectly good fuel. I think Ethanol is a perfectly good fuel source also. In fact with its high octane level (120-130) I think it could be a good replacement for 100LL even. It does take more of it than gasoline to get the same mileage but it does burn cleaner. I think it can work well in our engines when they are designed for it. Because of these things I do not want an engine that is "forbidden" from using anything except 100LL.

5.) Another issue is price. Although I don't like the price of any engine package if I buy new, the difference between the IO-320 and IO-360 in price is negligable. The difference between the O v IO versions of these engines is not enough to keep me away either when I consider the conveniences I can gain by using FI.

6.) My plans for flying this airplane include flying into the Rocky Mountains of Colorado, New Mexico, Wyoming, Montana, Utah, etc. Given the additional 20 HP the IO-360 will provide if I go with the 180 hp version over the 160 hp IO-320, I lean toward the IO-360 for having the extra hp for getting out of high density altitude mountain airports.

So those are the major determiners for what engine I desire. The IO-340 sounds very interesting because it is lighter than an IO-360 while providing equal to or perhaps more hp. However, the requirement for using 100LL only has me concerned. I still don't know yet what I will end up doing. One of these days I will have to make a choice and commit to something. For now I will continue to evaluate all the options including auto conversions.

RVBYSDI
Steve

[rgbewley]

Re: ethanol, can someone who is a fuel expert verify - I have recently heard that corn based ethanol requires .9 to 1 gallon of fossil fuel to manufacture a single gallon. Why then, would we look to corn based ethanol as an alternative to our gas price/supply issues?

[Mike S]

We shouldn't, it is happening beacuse of government interference, "fueled" by enviornmental wackos.

Mike