Subaru Reality

A forum to alternate source of power to include Eggenfellner and other conversions.
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rv6ejguy
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Post by rv6ejguy »

John, I wasn't commented on what Jan was saying in the early days- most people know today that the "160 hp" engines were never putting out anywhere close to this as evidenced by the performance people were getting. Many people were calling for dyno tests to back up the claimed hp when it was obvious to anyone who knew anything about engines that they couldn't possibly be doing this at the rpms they were turning. One look at the factory Subaru torque/ hp curve would show this.

NSI was turning out "220 hp" versions of their EJ25 packages about the same time with people swearing up and down that this was so despite their crazy "dyno" figures with unmatched hp vs. torque vs. rpm and SFCs as low as .285! Lay people believed this nonsense along with claims that an NSI Glastar was exceeding 200 mph in level flight! NSI is gone of course not because they didn't have enough gullible customers but because they didn't deliver anything on time.

Crossflow also made claims of 50% lower fuel flow than Lycomings at one time.

So yes, you are right that unsubstantiated claims were being made by all of the Sube converters. The results for the modern Egg conversions are now there on the forum for all to see.

Weight of the early Egg atmo EJ25s with the Quinti prop were usually within 30 lbs. of a typical O-360 C/S Hartzell installation. Performance was not anywhere close however. The STI was developed in response to customers wanting more performance. It was unfortunately a relatively complicated solution and heavier still and it would have benefited from more flight testing as any engine would. I feel an intercooled 2.5 turbo would be the best choice for RV6-RV9 airframes but I don't run Jan's business. HP when properly set up, was not in doubt after Robert Paisley blew off Dan Cs. 200hp RV7 much to the chagrin of Lycoming advocates. The fuel flow to do this could only be speculated at of course! At least this shut up the Lyco group for a while lamenting the lack of speed from the Subaru world.

The H6 was probably seen as the solution to complexity of the STI offering comparable hp. It is unfortunately even heavier. Given the factory 250hp at 6600 rpm, the current Gen 3 drive ratio and the 2700rpm prop controller setting, there is no doubt that the engines (EZ30-R) produce in excess of 200 hp at 5000-5400 rpm. The factory rating shows 175hp at 4200 rpm which would be a nice cruise power setting.

The new ECUs will permit closed loop operation at whatever power settings Eggenfellner deems appropriate. The bigger key to getting the best SFCs is in reducing rpm. Fuel atomization is actually just fine at the lower pressures used on previous generation H6s on both types of injectors used in these engines. I know, because I have flow tested them.

The hp question is not really settled in flight as the two designs are so different from a drag and prop perspective. This would be best settled on a dyno. This is a moot point in my view. The performance questions ARE best settled in flight where a straight speed vs. fuel flow contest would show the relative differences and is what most people really care about. I'm as anxious as anyone to see a side by side Egg H6 test and an O-360 in the same airframes. I hope someone with all the latest kit will do us the favor and post the results.

Many Egg buyers went for rides in Egg powered aircraft and liked what they experienced so they plunked down their money. We've read many a glowing review of how much they like the engines. These are not all newbies with limited experience, many of these reports have come from pilots with tens of thousands of hours in many aircraft types. They are not a bunch of mindless idiots. As I've said before, not everyone is interested in the last knot, many other things enter into the buying equation. Nobody had a gun to their heads to buy into the Subaru world. I'm glad that Jan is around to offer people an alternative who don't want a Lycoming.

About the time Jan's sales really spiked upwards, Lycoming was going through its various crankshaft troubles. Their magazine ads never admitted any serious problems were afoot. All was well, you could expect the same quality and performance you'd come to expect from them over the years-blah blah. Pure BS of course. What else were they going to say? We used to build good engines but now they aren't so good anymore. Marketing my lads and lasses and they didn't want to admit anything in the wake of several multi million dollar lawsuits while they tried to shift blame. Hardly noble behavior. I'm equally glad that the new head of Lycoming is cleaning house and making things right with some pretty major changes. It will be good for them and aviation as a whole.

I hope everyone is skeptical of manufacturers claims in aviation. Ask questions. If you don't get the good answers look elsewhere. Chad has done this. He is waiting and seeing how new developments pan out in both camps. Until we see otherwise, at this moment, the only way to see 170 knots in cruise with an RV on 9 or so GPH is with a Lycoming. If that is your sole criteria, the decision should be easy. It is nice to have the Lycoming advocates so interested in how others spend their money on engines where we just feel oh ok John is putting a Lyco in his RV- that's great!

I say to everyone in business (or politics for that matter) tell the truth, own up and find a solution. While it might be painful initially, things will be easier in the long run and you will earn respect. The other way does not work too well in most cases- at least not in the long term.

As far as my -10 goes, I have wished many times that I had just stuck the Lycoming in but I have dug a very deep hole which only I can climb out of. I just hope it was all worth it when (if) it gets done. :) Sanding cabin top and prepping the engine mount today. :(
Last edited by rv6ejguy on Sun Jun 17, 2007 10:07 am, edited 1 time in total.
Ross Farnham

Flying RV6A turbo Subie
Building RV10 twin turbo Subie

yukon
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Post by yukon »

Thanks for the great post, Ross. You are a good source for Subie developement history. Sounds like we both agree that ALL Subie marketers have exaggerated their performance in the past. The question remains, though, is the H-6 making anywhere near 200 hp at this time.
Even though it's a 6, it is only 3 Litres, and the weakling 4 cylinder Subie is only 50 CC shy at 2.5 litres. Question is, can the H-6 make about 90 more horsepower on that 50 cc? If so, how?

You seem to take great solice in Robert Paisley's victory over Dan Checkoway's normally aspirated RV-7. I believe this contest took place at
8000 feet, where Robert's supercharged airplane should have been developing 220 hp, Dan's about 150. Fuel burn??? Of course we don't know, but I'm sure it was in the neighborhood of 16 gph. Why do you consider it a victory when a superchargered airplane bests one that is atmo????

You say that the 2.5 Subie is only 30 lbs heavier than an IO-360. Trouble is it is only making about 110 hp. 30 lbs heavier for 70 less hp???? Those are really bad numbers.

Well, back to my canopy!


John R
RV-9 QB

Spike
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Re: Not the Best, Just Another Engine

Post by Spike »

Great conversation gentleman. Though, I offer up a pre-emptive reminder to keep your debate a friendly discourse.
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yukon
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Post by yukon »

Spike,

I think our conversation is friendly, even though we don't always agree!

Why does your signature say "Lindy Bound"?

John

Spike
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Post by Spike »

yukon wrote:Spike,

I think our conversation is friendly, even though we don't always agree!

Why does your signature say "Lindy Bound"?

John


I would agree, hence my use of "pre-emptive." A few statements did however read somewhat accusatory.


Putting "Lindy Bound" in my signature is a motivator for me. I enjoy building, however sometimes I need a reminder to take my time and strive for excellence. Nothing speaks excellence, in my mind, like the Lindy awards given out at Osh for well built aircraft. Hence being "Lindy bound."
http://www.rivetbangers.com - Now integrating web and mail!
Current Build: 2 years into a beautiful little girl

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rv6ejguy
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Post by rv6ejguy »

yukon wrote:Thanks for the great post, Ross. You are a good source for Subie developement history. Sounds like we both agree that ALL Subie marketers have exaggerated their performance in the past. The question remains, though, is the H-6 making anywhere near 200 hp at this time.
Even though it's a 6, it is only 3 Litres, and the weakling 4 cylinder Subie is only 50 CC shy at 2.5 litres. Question is, can the H-6 make about 90 more horsepower on that 50 cc? If so, how?

You seem to take great solice in Robert Paisley's victory over Dan Checkoway's normally aspirated RV-7. I believe this contest took place at
8000 feet, where Robert's supercharged airplane should have been developing 220 hp, Dan's about 150. Fuel burn??? Of course we don't know, but I'm sure it was in the neighborhood of 16 gph. Why do you consider it a victory when a superchargered airplane bests one that is atmo????

You say that the 2.5 Subie is only 30 lbs heavier than an IO-360. Trouble is it is only making about 110 hp. 30 lbs heavier for 70 less hp???? Those are really bad numbers.

Well, back to my canopy!


John R
RV-9 QB
I'm thinking you mean 500cc more in the case of the EZ30-R compared to the EJ25? The latest EJ25 with AVCS is rated at 175hp, the EZ30-R at 250hp. Yes, I have little doubt that at the 5400 rpm takeoff power setting, the EZ30-R is making in excess of 200hp.

The Paisley/ Checkoway thing merely put rest to what the Lyco guys were erroneously claiming that NO Subaru powered aircraft was going to beat a Lycoming powered one. Absolute nonsense of course since it doesn't take much of a supercharged or turbocharged Sube to make 200+hp. The stock STI is 300. You don't need to be a brain surgeon to figure out who will win that contest. Dan's plane was not at its best speed altitude but I submit that Paisley would have won even at SL although by a lesser margin. Dan would have been burning between 13 and 14 gph at SL at a rich setting so the fuel flow wouldn't have been too different. I burn 12.5 or so at climb power (35 inches and 4600 rpm).

Most auto conversions are not geared properly to take advantage of the engine's max power rpm range so they have tended to be lame in many instances. No real surprise there. With a 2.1 to 1 ratio, I think the modern EJ25 would duplicate O-320 performance in an RV. I did a detailed weight analysis of this engine with a custom cowling and radiator setup, mount, oil cooler, exhaust, Sensenich C/S prop, alternator, starter, fluids and redrive. FF weight was about the same as an O-360/ Hartzell. Hp should be close to 165 at 2700 prop rpm. The revised cowling/rad setup should reduce cooling drag substantially over cheek mounted rads. This would be a better setup for the RV9 than the H6 in my opinion. Could be done if someone wanted to.

John, I'll do your canopy if you do my cabin top. I thought the canopy on the 6A was a bear. Nothin' compared the the RV10! How I wish Van had put a slider on the -10 a la Tiger or Navion! I've just dusted myself off after another 3.5 hours of sanding after about 30 previous hours of trimming and sanding.
Ross Farnham

Flying RV6A turbo Subie
Building RV10 twin turbo Subie

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