Sube vs. Lycoming

In a recent, side by side test, Robert Paisley's Eggenfellner Subaru STI powered RV7 was able to pull past Dan Checkoway's very fast 200hp IO-360 powered RV7 despite Robert's plane having a heavy passenger and Dan's plane having an empty seat. Another myth put to rest now that the Eggenfellner Subes can't keep up with the best Lycomings.

Oh Dan say it isnt so.

Did you hold back for pitty?
Kahuna

It's true

At first he had 2 knots on me, but I messed with mixture and was able to achieve the identical GPS groundspeed, flying side-by-side. But like it was mentioned, he had a heavy passenger onboard. He would take me if all else was equal.

But that's at 8500', density altitude of maybe 12000' due to high temps. And presumably any altitude higher than that, he could easily pass me.

We didn't compare fuel burns, but it would have been interesting.

I think after OSH, Robert and I will go up and do some side-by-side testing at lots of altitudes and seriously record all the parameters. Specifically fuel burns, relative true airspeeds, etc.

I suspect I will be able to take the Subaru setup with my 200hp IO-360 at altitudes UP to about 8000' DA...at which point the Subaru will probably start kicking my butt. But I also assume it will come with a price, that being higher fuel burn.

But let's go do some testing and see exactly how it plays out.

)_( Dan
RV-7 N714D (560 hours)
http://www.rvproject.com

Dan Dan Dan Dan, tell me it was all dream

Oh my Gosh, the Subie Guys are going to be more out-O-control.

Good for Robert Paisley's, congrats. Uhaaa I would love to hear from Robert on what improvements he might have made or not made over a stock Eggie, what kind of prop did he used?

Actually this is not new news. Usually the turbo Subie will start to give an advantage only around FL100 to FL120 and above. This was proved out in a Custom turbo Subie vs. Lyc side by side fly off.

http://www.sdsefi.com/rv14.htm

From what Dan stated it sounds like the speed was matched at DA of 10,500-12,000 feet. That is to be expected. It would be interesting to take it up even higher. I wounder it there is TIT (turbo inlet temp) limit?

As far as Gross weight factor: According to Van's aircraft specs, solo weight vs. Gross weight is worth (1) MPH. So that is not an issue.

So for the Subie to do "Butt Kicking" they would need to fly above 10,000 -12,000, if kicking butt means a matched or 1-3mph.

Flying high is great if you plan on flying at that altitude and using O2 to get the advantage of the Turbo. If Dan where to turbo/intercool his Lyc than we would have a different result. It is not as much as the Subie is making more HP it is more that the Lyc is loosing HP. From the charts Dan's Lyc was around 65% or 130-122hp. (Of course no one mentioned RPM?)

I flew turbo'ed Lyc's before at FL250 in a TS Aerostar TS61. It was a mid-wing twin with turbo/injected Lycs (6 cyl). This model was not a pressurized, so this is where I grew to hate sucking O2 from a mask or cannula. Flying at FL100-FL120 all day without O2 can give you a headache.

Any way not to take anything away from Robert's turbo charged Subie powered RV-7, but it is now time to do some real side-by flight testing and get real comparison with all the numbers: RPM/MAP, weights, temps and fuel burn.

I like the side-by-side comparison, which is great way to level the field. The way Van compared two factory Demo RV's to two Rotary powered RV's was interesting. (In this test the 200 hp Lyc was slower than the 180 HP lyc, no doubt due to the fact the 200 HP lyc was tired from a few thousand demo flights. Also the Rotarys had a very slight edge, but burned huge gas doing it.) To determine the fuel burn Van's test started with full tanks and after flying a set course, landed and refilled, comparing use like we do with our cars. Also a side-by-side climb test was interesting. This is just the kind of thing the Cafe Foundation should be doing.

Oh boy Dan we will never hear the end of this. Cheers George

The issue between the two is not HP- it is torque. The Lyc has more displacement and a long stroke- much like a diesel engine. The Lyc generates significant torque at low engine speeds, which falls off rapidly as rpm increases.

The Subi is a smaller engine with a short stroke and limited torque output; it converts high rpm HP to the needed torque levels through a reduction drive.

I suspect the Lyc has a significantly higher fuel burn rate because it is less efficient (wastes energy generating friction, vibration, and heat). The Subis have a big advantage in smooth operation, durabiity, and part replacement costs.

BTW, head to head speed comparisons are a terrible way to comapre engines- there are way too many variables involved. The only reliable comparison would be to test both engines in the same plane, same prop, or tested on the an engine dynometer under identical conditions.

Actually, Robert's Sube is not normalized. It makes its max power at sea level just like the LYC, it looses power at the same rate in the higher altitudes just like the LYC. Robert has the STI engine from Subaru/Eggenfellner. It is designed for max HP at all altitudes. The 2.5l single cam that Egg also sells is normalized. In other words, it's max MP is 34 inches, and it can sustain that to somewhere in the 14,000 foot range. Robert's supercharger is maxed out at 50 or so inches at sea level, and drops off at the rate of 1 inch per 1000 feet just like the LYC There is no doubt that the 2.5l with the normalizing supercharger gains power relative to a normally aspirated LYC as they climb, but that is not the case with Robert's engine as I understand it.

Nathan Larson
N217JT RV9E
310 hours on Egg/Sube 2.5l single cam normally aspirated. Looking forward to learning more about Robert's engine at Oshkosh

I disagree

cobra said:

I suspect the Lyc has a significantly higher fuel burn rate because it is less efficient (wastes energy generating friction, vibration, and heat).

Click to expand...

Uhaaa you are guessing, no one reported FF, MAP or RPM, and you are correct, all you can do is suspect. However I disagree that the Lyc is burning more gas. From the Lyc IO-360 (200hp) power chart, fuel burn, best power @ 2600 RPM at 65% is around 11 gph. From http://www.sdsefi.com/rv14.htm a Turbo subie was measured at 70lbs/hr or more flat out, or approx 11.7 gph (at high pwr @ 5,000 ft, 14 gph was recorded). There is no free lunch, and stroke and torque has little to do with it. You need so much thrust to go and that cost gas. A Subie is an internal combustion engine folks. Electronic fuel injection, overhead cam 4-valves and water cooling is more for car issues and of only little advantage in an airplane at constant power. BTW in a diesel , fuel efficency comes more from the high compression than stroke/displacement (piston dome and positive displacement supercharges).

cobra said:

BTW, head to head speed comparisons are a terrible way to compare engines- there are way too many variables involved. The only reliable comparison would be to test both engines in the same plane, same prop, or tested on the an engine dynometer under identical conditions.

Click to expand...

I disagree there are no excuses and heads up is a tried and true way to test and eliminates variables. Who cares what a dyno says, as installed in actual conditions is the best way. Real performance not numbers. Also it is hard to get the same airplane, but the consistency of RV's from accurate kits is pretty equal. Dan's RV is nice but unpainted. If it was panted and waxed it would go 2 mph faster (verified by the cafe foundation BTW ). Installation and props is the main part of the issue. I always said the draw back of the Subie is electric props (required) and poor cooling drag from work around heat exchanger installation. Installation is every thing, form, fit, function, weight, systems are all relevant.

With variation in the atmosphere testing in the same place at the same time is fair and accurate. With out side-by the Subie's small advantage would not be possible to detect, because measuring TAS with in a few mph with GA instruments is more than the tolerance can allowed. Are you scared? "Heads-up or shut-up" is what they say at the track. Right now the Subie has the bragging rights, so let the games begin (fun). By the way I like Subies and this is all in fun, but lets move the discourse further than beating the horse over again about opinion and preference.

cobra said:

The Subies have a big advantage in smooth operation, durability, and part replacement costs.

Click to expand...

This has nothing to do with performance and is subjective. The cost of a new O-360 has dropped over $4,000 over the last few years due to the clone market. Lets just talk performance. A turbo Subie Eggy kit engine is way more than a Lycoming to purchase, so let's not go there. The cost of owner ship is only a guess at this time. All I know is I flew my light twin everyday for 3 years and never did any thing other than oil/filter changes and plug cleanings. After three years I sold the plane for more than I payed for it. Sam with my RV-4. My O-360 core I just overhauled for my RV-7 cost me a total $13,000 with dual elec ignition. What does a total Eggy set up cost? What is the resale of Subie RV's vs an O-360 Lyc RV? Again cost of ownership and smoothness are subjective. Side-by performance is not subjective.

Yes auto engines can match or get a slight speed advantage at altitude but they are working real hard (high RPM and MAP). A Lycoming is rated at 100% with no limitation except CHT/OIL Temp. Not that Dan's plane is slow, but with a Sam James style cowl and sealed cooling pressure plenum his RV-7 would go up to 10mph faster. Cooling drag is an issue the water cooled engine crowd must address. The URL I referenced twice above is an example of a builder really experimenting with different ideas, including a fuselage radiator. Worth a look. I would love to see how fast his RV-6 Subie turbo (big turbo with intercooler) is against Robert's RV-7 Eggy Subie.

Cheers George

Robert's engine

Robert's engine has a supercharger, not a turbo. I believe the prop is the MT Propeller MTV-7 - at least that's what Eggenfellner delivered with my STI engine.

From what Robert posted on another list, the main work he has been doing on the installation is to improve the airflow efficiency through the cowl.

My original post was merely to inform of the progress being made by Eggenfellner and Robert on the supercharged STI package. Robert's RV7 uses an Eaton supercharged Subaru 2.5 with a barometric controlled compressor bleed system. This is quite a different animal from a turbocharged engine. Robert has done some experimentation with radiator ducting and cowl flap modifications plus some testing on the intercooler setup.

Racetech owns the Turbo Sube 6A GMCJETPILOT refers to here which is held back from performing better by the IVO propeller currently fitted. This prop is unable to absorb even modest power (over 30 inches/ 4600 rpm) above 10,000 feet. If we were willing to spend the money on an MT C/S, we have no doubt that this aircraft could exceed 200 knots+ TAS at fairly low power settings. Currently top speed is 182 knots TAS running 34 inches/5000 rpm 15,000 feet with the IVO at full coarse pitch and quite unhappy. There is much conjecture on how good/ bad the IVO is working with this combination of redrive ratio, airspeed and pitch and whether the airfoil is well matched. Only way to tell would be the fit a different prop and see. Our cowling radiator setup has high cooling drag in our view as well which is why the new RV10 project will use a P51 style scoop. For the time being, we use the 6A as a testbed for the SDS EFI, redrive, turbocharger testing, cooling system testing plus staying current. The lessons learned will be applied to the -10. We'll continue to improve all aspects of the Subaru installations just has Eggenfellner has with his as we learn more.

The Egg Subes tend to have relatively high fuel flows at high power settings due to the use of the OE ECUs and the fact that they jump into open loop mode at relatively low power settings. The default air/fuel ratios (AFRs) in open loop are around 13.0 to 1. Recently, Egg has added a new fuel pressure regulator to drop baseline fuel pressure and leaning the AFRs in open loop to lean the mixture at higher power settings. This appears to be working although there are unknowns with the self learning features of this ECU and whether the AFRs will be eventually return to what Subaru intended. Testing will soon prove this out.

We currently feel that the frictional losses are relatively higher on a Sube turning at 4500-4900 than a Lyc at 2600 rpm. This negates some of its advantages in the fuel flow department. The RV10 will use a different redrive ratio and an MT C/S prop in an effort to get cruise rpm down to about 4000 rpm where volumetric efficiency is highest and SFCs are lowest. We also raise the compression ratio to the 9.5 range to boost thermal efficiency. We hope to recover more work from the turbos to reduce pumping losses by cruising at lower rpm and higher manifold pressures. Current leaning experiments have not been carried to peak EGT or LOP operation at this time as no one has previous experience running these engines under boost in cruise. With EGTs currently limited to 1450F, we see the SFCs similar to a Lycoming. This represents an AFR of 14.2 to 1 so there may be 10% improvement in SFCs possible. Our current feeling is that a turbocharger is superior to the Eaton type blower for power, reliability, fuel flow and noise reduction however many might disagree. Both have been shown to work well and I welcome further testing of both strategies.

We feel that side by side testing is the best as there are too many variables with cooling drag, altitude performance, exhaust thrust and propellers to do useful terrestrial testing. I'd have to agree with GMCJET here.

GMCJET is right, sucking on O2 is a drag. While the RV10 will have built in O2 and the turbos will be well matched up to 18,000 feet, we want equal or better performance to the IO-540 installation in the normal realm of 8000-12,000 feet cruise altitudes. If we decide to use the nose tubes, we expect to see 190-200 knots cruise at 75% and 18,000 feet.

As far as these engines working hard, no. The piston speeds are actually lower on the Sube so 4600 is no harder than a Lyc at 2700. The STI 2.5 and EJ22T are engineered to operate under boost for extended periods with piston oil sprayers, stronger pistons, pins and blocks. The basic longblock has been shown capable of making over 900hp for short periods at over 100 inches hg Ab and 8500 rpm. Cruising at 150 hp is far below any critical stress levels. Of course there are coolant temp, oil temp and EGT limits just as on any engine.

As a sidenote I've observed a few cases now of 180hp O-360s, outperforming 200 hp IO-360s on several RVs now. What is up with that?

Hey George,
I always enjoy your counterpoints. My only comment regarding plane to plane comparisons is that (I understand) at full power, top speed operation, the aerodynamics of the specific planes have more effect on top speed than the engine/prop combo does. The plane is near a point of fast diminishing returns as far as speed is concerned. I suspect that pilot skill is every bit as important there too. How else can you explain the race result differences from seemingly identical planes with identical motors/power ratings.

I fully agree with you that various engines produce similiar power/ fuel flows when they operate at PEAK output. My thought is simply that the Lyc is closer to full power output at 2300 rpm than the Subi would be at 4500 rpm- the Sub is still building up to its peak. BTW, the Subi should be good for more power thru tuning than the Lyc, simply because it is capable of higher RPM- we only need to flow a little more fuel and air through.

Ive been kicking these ideas around wondering what effects might be expected from mounting a Mazda Renesis rotary in a 7A (capable of 250+ HP in a lightweight package). Im guessing faster climb rates, maybe a little more load capacity, but not a whole lot more top or much faster cruise speed than the 200HP setups. I like the Renesis because it is newer and refined, more efficient, and quieter than earlier rotaries were, not so much for the extra power on tap.

A turbo Subie Eggy kit engine is way more than a Lycoming to purchase, so let's not go there

Click to expand...

Actually the turbo (supercharged) subie and a 200HP io-360 run about the same price. A quick look around shows the io-360-a1b6 to be about $31k, just for the engine. A e-subie is about $29k, for the engine. Add up prop and all the accessories and you end up about the same...

I know you can get rebuilt 180hp o-360's a lot cheaper, but for comparison's sake, that's what Dan has in his plane. And for that matter, there's cheaper (non-turbo) subies out there, too...

cobra,
I'm right there with you on your last thought about the Renesis. Although, I'm not sure you will save much in the weight department. The engine (block) itself will be lighter, but when finished with accesories, it will be just as heavy as a lyc/clone. That being said, I am still planning on a Renensis installation with a Catto three blade. A friend of mine is a couple of years ahead of me on his -7 project, and has his Renesis mounted, and should be ready for his first start later this summer-his business keeps him away from the project a lot. I'm really looking forward to this, and learning more for when I get to that point.

I can't say enough about rotory power. Everyone will argue with me, but IN MY OPINION (that's all it is), there is no better engine out there from a reliability, durability, and technological standpoint. I will probably burn more fuel...big deal. I can save money by running auto gas if I want to--it will burn either. I'm not looking for the cheapest way to go somewhere fast, I just want to go fast, safely. I am a fan of Lycoming (I've owned two) or clone engines, I just feel that all those moving parts COULD cause a problem sooner than a rotory with 3 parts that move.

I have some descent experience with rotories in cars with three RX-7's in my past, and they are just great engines.

Again, this is my opinion, and I completely respect everyone's thoughts on this forum, and I love the never ending battles on this issue!!

cjensen said:

cobra,
I'm right there with you on your last thought about the Renesis. Although, I'm not sure you will save much in the weight department. The engine (block) itself will be lighter, but when finished with accesories, it will be just as heavy as a lyc/clone. That being said, I am still planning on a Renensis installation with a Catto three blade. A friend of mine is a couple of years ahead of me on his -7 project, and has his Renesis mounted, and should be ready for his first start later this summer-his business keeps him away from the project a lot. I'm really looking forward to this, and learning more for when I get to that point.

I can't say enough about rotory power. Everyone will argue with me, but IN MY OPINION (that's all it is), there is no better engine out there from a reliability, durability, and technological standpoint. I will probably burn more fuel...big deal. I can save money by running auto gas if I want to--it will burn either. I'm not looking for the cheapest way to go somewhere fast, I just want to go fast, safely. I am a fan of Lycoming (I've owned two) or clone engines, I just feel that all those moving parts COULD cause a problem sooner than a rotory with 3 parts that move.

I have some descent experience with rotories in cars with three RX-7's in my past, and they are just great engines.

Again, this is my opinion, and I completely respect everyone's thoughts on this forum, and I love the never ending battles on this issue!!

Click to expand...

Chad,
The rotary is an excellent engine and to stay sort of close to the point of this thread, is so for the same reasons as the Subaru, modern technology. The Lycs are FINALLY starting to show up with modern accessories which helps. The rotary really makes a better aircraft engine than car engine! It has no problem with high % power operation. The fuel burns are also very reasonable for the same power level. The engine becomes more efficient in the upper half of it's operating range. The are several sources working on aluminum side plates for the rotary, which if successful will really help as the engine will be 25-30 pounds lighter! Be sure to get a high reduction ratio PSRU for the Renisis model like Tracy Crooks 2.85:1 unit the rotaries LOVE high RPM.
Bill

"The fuel burns are also very reasonable for the same power level."


sound track: strange bubbling noise followed by a sudden inhaling noise...then coughing....

Rotaries burn much more fuel per power, even with turbos than Lyc's as recent tests have shown...heck even in auto racing, the rotary was unusable in series where fuel burn was controlled. They are thirsty by car racing standards, when compared to other racing cars....

Yep, they burn more...oh well. I won't deny that.

I still think it's a better engine. So what if I burn 13 or 14 to your 9 or 10. That's not a huge issue for me, or most of us who are going to run these.

No valves, rings, push rods, push rod covers, springs, bearings, lifters, rollers, con-rods, pins, valve covers, o-rings, etc.

Like I said, I do like lycomings, and their counterparts. I just think that there are better options out there for this application.

Jconard said:

"The fuel burns are also very reasonable for the same power level."


sound track: strange bubbling noise followed by a sudden inhaling noise...then coughing....

Rotaries burn much more fuel per power, even with turbos than Lyc's as recent tests have shown...heck even in auto racing, the rotary was unusable in series where fuel burn was controlled. They are thirsty by car racing standards, when compared to other racing cars....

Click to expand...

Testing by Tracy Crook has shown comparable fuel flows to a Lycoming at the same TAS when aggressively leaned. John Slade's initial tests with a turbocharged 13B with high CR rotors also show comparable fuel flows when properly leaned using the same ECU. It appears that the Wankels are capable of LOP operation with no ill effects. I would like to see some side by side testing to verify these claims. Any takers?

The Power Sport Wankels tested earlier this year against Van's demonstrators use a different ECU. Not sure what AFRs they were running but their fuel flows were quite a bit higher for the flight. I like Van's idea of filling all the planes up, do the mission side by side then fill them up again afterwards to see what the total fuel burn was. This demonstrates the efficiency of the engine during the whole mission, idle, climb, flat out, cruise etc.

Tracy C. reports 6.0-8.2 gph (172/202 mph) in his RV-4 w/1987 Mazda 13B, his redrive, and ecu. Thse rates seem pretty close to the rates Ive seen published from leaned out 360 Lycs (at least before the heads get too hot...) as do performance comparisons.

Supposedly, concerns with fuel burn are related to cost. The fuel burn rates are so close that they are not significant. Value life engineering suggests the more important cost factors between the Lycomings, Continentals, Egg Subarus, and Mazda's involve initial cost, the estimated TBO, and overhaul costs. The Mazda rotaries win those comparisons, but involve a more difficult install since a complete kit is not available.

Not new

zsadecki said:

Actually the turbo (supercharged) subie and a 200HP io-360 run about the same price. A quick look around shows the io-360-a1b6 to be about $31k, just for the engine. A e-subie is about $29k, for the engine. Add up prop and all the accessories and you end up about the same...

I know you can get rebuilt 180hp o-360's a lot cheaper, but for comparison's sake, that's what Dan has in his plane. And for that matter, there's cheaper (non-turbo) subies out there, too...

Click to expand...

FYI, my engine was $28,260. Would have been around $25,700 stock. It's technically an overhauled engine with new crank, new cylinders, etc. Practically the only thing "used" was the case, basically. I had looked at brand new engines but in the end decided that overhauled was the way to go -- with AeroSport Power at least.

I spoke to Robert yesterday, and he and I will go flying together after OSH (he's going, not me). I hope we can come up with a whole spreadsheet of data points of altitudes, airspeeds, and fuel flows. I think it will be pretty clear where the high & low points of each powerplant are.

I will be extremely surprised if the Subaru runs as economically as my IO-360 at any airspeed. I have an open mind, though! We'll see in a few weeks.

)_( Dan
RV-7 N714D (564 hours)
http://www.rvproject.com

As Mr. Burns would say- eeexcellent. This will be very interesting. I had a great time doing the fly off against my friend's Lyc -6A. We await the cold hard facts... and thanks for lending yourself and aircraft for this test and having an open mind.

Aerosport doesn't list any rebuilt 360's on their web page, but I imagine a phone call might give different results.. Anyways, from their web page:

New Aero Sport Power IO-360-A1B6 (200 H.P.) Engine:
Outright $ 32,900.00 US

Ouch! I hate to even think about that, as it'll probably be the engine I end up with, and it sure to be more in the year or so when I order it...

180HP is the way to go for me

rv6ejguy said:

As a sidenote I've observed a few cases now of 180hp O-360s, outperforming 200 hp IO-360s on several RVs now. What is up with that?

Click to expand...

zsadecki said:

Aerosport doesn't list any rebuilt 360's on their web page, but I imagine a phone call might give different results. Anyways, from their web page: New Aero Sport Power IO-360-A1B6 (200 H.P.) Engine: Outright $ 32,900.00 US

Ouch! I hate to even think about that, as it'll probably be the engine I end up with, and it sure to be more in the year or so when I order it...

Click to expand...

Why spend $10,000 to $13,000 for and extra 20HP an 30lb's more weight? (no offense Dan). The 180 vs 200 Lycoming debate is as never ending as the automotive alternative engine debate. If you can stand a 180HP O-360, you are looking at $19,200 new.

What speed does 20 HP make? Ans: About 7-8 MPH in theory. I say theory because that is not always proven out in service. So for all that extra weight and purchase price you may only gain 4 to 7 MPH, all things being equal. HP is one of the least efficient and most expensive ways to go faster. Reducing drag gives you speed with out burning more gas. I mentioned an example of adding a Sam James style cowl and sealed plenum (or modification of the stock cowl and baffle kit) as being worth 7-10MPH, which is equivalent to adding 20-25 HP. A 180HP engine can go as fast as a 200HP RV by just reducing drag and weight a little.

Also the 180HP clone engines on the dyno, in stock config, are consistently making more than the min 180HP. Now add electronic ignition, 4 into 1 pipes and 9:1 or 9.5:1 pistons you can make 190HP easy. Also rebuilds on the IO-360 (200HP) will cost more. Nothing wrong with 200HP but a RV can fly better than 99.9% of the GA SE fleet on just 150HP, so 180HP is plenty. Trust me. You never can have too much HP, but at the expense of cost and weight to get 20 more HP, the 180HP is ideal bang for buck the RV in my opinion. This is way cheaper than any of the highe end supercharged/turboed Subaru kit engines by a wide margin.

Cheers George

gmcjetpilot said:

Why spend $10,000 to $13,000 for and extra 20HP an 30lb's more weight? (no offense Dan). The 180 vs 200 Lycoming debate is as never ending as the automotive alternative engine debate. If you can stand a 180HP O-360, you are looking at $19,200 new.

Click to expand...

George,
Where did you see that price for a NEW O-360? Vans lists the O-360 (180 HP) at $23,925.00 new, and you have to have bought a kit from them to get that price! That is a difference of $4,500.00 bucks people might want to know.

Bill Jepson
Rotary10-RV

Here ya go

Rotary10-RV said:

George, Where did you see that price for a NEW O-360? Vans lists the O-360 (180 HP) at $23,925.00 new, and you have to have bought a kit from them to get that price! That is a difference of $4,500.00 bucks people might want to know. Bill Jepson Rotary10-RV

Click to expand...

New Lycoming engine prices, (ECI or Superior)

http://www.aerosportpower.com/Prices.htm#NewEngines
New Aero Sport Power O-360 Engines:
Fixed Pitch (A2A) Outright with ECI Components $ 19,800.00
Constant Speed (A1A) Outright with ECI Components $ 20,300.00
($500 cheaper for the O-320 fixed/constant speed)

http://www.mattituck.com/
Selection Engine Description Price
Standard TMX O-360 180 hp Engine for Fixed Pitch $ 19,490.00
Standard TMX O-360 180 HP Engine for Constant Speed $ 19,790.00

True above are not a Textron Lycoming, but than this is for an experimental. Prices have gone up from $19,200 about $190.

--------------------------------------------------------------------------

This is what I paid for my O-360A1A (180HP) Textron Lycoming $9,500

For entire firewall forward including constant speed prop and all required accessories, about $14,500

I bought an O-360A1A (firewall fwd) with 700hours since major (about 2600 total).

I paid $2500 for engine with extra parts and sold the exhaust, wet vacuum pump, generator (yes a generator), two magnetos, feathering prop and prop governor (came off a Piper Apache twin with a 180hp conversion). I ended up having about $1500 into the engine after I got rid of all the stuff. I did not have to rebuild it but there was a suspected prop strike with the engine shut down (long story), but I had it checked out. The crank was fine, but decided to overall it why it was open.

Overhauled O-360A1A new EVERYTHING required/recommended by Lycoming during overhaul, valves, pistons, rings, etc & (overhauled cylinders and Carb) Crank inspected checked out, stress relieved and re-cad plated.

Core Cost of Lycoming O-360A1A core $1,500
Cost to Overhaul above Lycoming per above $8,000
Purchased overhauled used Hartzell HC-C2YK constant speed prop $2,500
Purchased yellow tagged Prop Gov Woodward 201105 $300
Purchased New ND alternator and brackets $225
Purchased new Custom 4 into 1 exhaust to my specs w/ heat muff $700**
Purchased new SkyTec starter (eBay special) $250
Purchased used Stewart Warner oil cooler and overhauled at POC, $250
Purchase Misc parts, throttle, mixture, prop controls, Vans airbox, brackets $250
Purchase dual electronic ignition, est. approx price $2000
Freebie, almost new mechanical pump & spin on oil filter adapter $0

TOTAL
Just for the engine with all the accessories except carb, taken out $9,500.
Approx price $ 14,500 for Zero time O-360A1A with new accessories and dual electronic ignition, constant speed prop.

Now for autoengines:
I would like to see an auto engine do better than that. What does a scrambled Egg sell his Subaru engine for? OR PowerSport Rotary cost?

I think a Egg goes for close to $30,000.00 You can by a whole Subaru Outback or Forester for less than that. That is crazy money. Plus you have to go thru the monkey motions of adding extra batteries, fuel pumps (including a $400 6-port fuel selector) and plumb all that plus the radiator stuff. That does not even include an expensive electric (sucks) prop, which cost another $8,500. What happened to cheap power? Also if you have a special Egg part or Real-World-Solution rotary engine part/accessory, only Egg or RWS can sell it to you. You are stuck with their price, if they are still in business.

I can get Lycoming parts (pistons, cylinders, valves, cranks, cases,..) and accessories (Props, governors, ignitions, fuel pump, oil coolers, etc..) from 1000's of retailers, shops and maintenance facilities.

There are 3 manufactures of "Lycoming" engines. For Lycoming parts and accessories there are: 4 manufactures of electronic ignitions, 2 manufactures of fuel injection, 5 manufactures of hydraulic constant speed props (and at least 5 fixed pitch prop makers), 4 manufactures of light wt. starters, 4 manufactures of exhaust (recommend Aircraft Exhaust below) and the list goes on and on.

I hope that answers your question, for those who want the cheaper, easier to install and more parts availability of Lycoming power. You get what you pay for.

Cheers George


**http://www.aircraftexhaust.net/
Highly recommend them. They can make custom exhaust (which cost $1200 normally but got mine by special intro purchase a few years ago). They also have stock off the shelf RV exhaust systems and the best cabin heat system around. They have standard cross-over exhaust also for much less than the custom exhaust. Call them before you buy and exhaust. Tell them RV-7, 4-into-1 George sent you. (I have no interest in the company except being a very happy customer who appreciates quality work.)

Well if you overhaul yourself and start with a used engine, my turbo Sube was $8700 US. New prop, new reduction gear, overhauled engine, new turbo, new intercooler, rads, mount, alternator, starter, hoses, 321 SS tubing. Of course my labor was free.

Comparing new to new, ready to fly, the Lyc clones with Hartzell prop are cheaper than Eggenfellner or other similar auto conversion which are ready to bolt up using the MT prop.

All depends how handy you are with the wrenches or how deep your pockets are.

Apples and apples

rv6ejguy said:

All depends how handy you are with the wrenches or how deep your pockets are.

Click to expand...

Not many folks have your abilities, skill, resources and experience. Most builders are lucky to finish. However I agree with you 100%, apples and apples. If you are willing and able to put some sweet equity into it you can save money regardless of what engine you use. With the auto conversion you have to make many of the installation items, which is a notch up on the skill level meter but not impossible.

The Rotary guy's (Tracy) seem to have a leg up on the do-it-yourself method of auto engine conversion with critical parts and well documented conversion techniques. I think the number I heard was about $15,000 for a fixed pitch rotary set up, all do-it-yourself. However with that said I know of two guys who bought firewall fwd O-320's off of planes (one salvaged one upgrade) with all accessories (including prop) for about $15,000, in flying condition.

My point is when you compare NEW off the shelf firewall forward engines (kits), Lycoming, Subaru or Mazda, the auto engine kits do cost more to buy and install. Auto engines do have the potential for the most savings for the 100% do-it-yourselfers, but the performance they get will not likely be anything close to your efforts or a Lycoming. Your conversion is not run of the mill, but very refined. I have seen a few custom subies (RV-4, Long-EZ) that where also very well done, but most builders will match your attention to detail.

With that said I doubt your aircraft and all the work and money you have into it is less than if you went with a Lycoming outright, but you are doing more than building a plane to fly. You are actually a true experimental builder and pilot, unlike us pretenders who just build planes to plans like 1000's of other RVs. I appreciate and admire all the work you have done, but most (like me) just want to go fly; If you want to be a tinker (inventor, experimenter) the auto engine is a great hobby and learning tool, but if you just want to fly than a Lycoming is the best option in my opinion. To satisfy my experimenter/engineer side I am spending my tinker time in cutting cooling drag with cowl and airframe mods. The engine is stock but played with electronic ignition, 4 into 1 exhaust and special (secret) oil cooler installation. For racing I may look into a dry Nitro system? (Any thoughts on that, dry wet?)

Being a cheapskate, bargain hunter I put my time into finding a good used Lycoming and doing the rebuild myself, and I also learned a lot. You can find a used flyable Lycoming, but even if you go all new, you can get a clone for less than $20K. The other point is there is a lot of competition for parts and accessories, so for less than another $5,000 you can get all NEW bits and pieces to bolt on. With a constant speed prop may be $8,000 for all new stuff. The part of the equation is there are lots of used parts and accessories for Lycoming, so the used & overhauled market is there to save money. You really don't find many good cheap used special parts, like a PSRU's, that are made for your auto engine project.

George

PS for anyone who wants to know how to do a Subaru installation right and how to do flight test, check out rv6ejguy's web site. It is the best I have seen. May be he will tell us his secrets?

I'll second the recommendation for RV6ejguy's site. There is a lot of excellent information applicable to cooling any automotive conversion.

George,
The cost for a basic rotary DIY conversion is more like $6000 + whatever propeller you choose, and even bigger savings come at rebuild time...

1200 for good low mileage Japenese motor (maybe less in used car)
~600 for overhaul kit
~2500 for the redrrive
another 1000 for the ECU. The rest of the parts are insignificant cost, available from autoparts houses and/or junkyards, or are fabricated (some welding required).

That is cheap

cobra said:

George, The cost for a basic rotary DIY conversion is more like $6000 + whatever propeller you choose, and even bigger savings come at rebuild time...

another 1000 for the ECU. The rest of the parts are insignificant cost, available from auto parts houses and/or junkyards, or are fabricated (some welding required).

Click to expand...

It is hard for me to predict the cost of a homebuilt Rotary. I believe your numbers.
I was going on this good site, http://members.aol.com/vp4skydoc/

From the above RV-6 (rotary powered) builder site, list of FW cost:
First Engine Pick up ('91 turbo, with xtras) $1300
Engine Rebuild (myself - a great experience) $600
Second Engine with manifolds and coolers $7500
RWS RD-1B PSRU $2800
RWS EC2 Engine Computer $900
Re-make Engine mount $900
Mount Coolers and Make Ducting $500
Plumbing and wires $800
Fuel Pumps $200
AC-Delco Coils $125
Cowl Modifications
Propeller with spinner $700
Sensors $300
Second Engine Rebuild $100
Miscellaneous Welding $500
Making intake Manifold $50
Making Exhaust $200
Turbo Re-Build $600
TOTAL $18,075

If you took the $7500 engine, $700 prop and $200 turbo off you have a total about $9,675, which seems reasonable for a non turbo engine. This is about half the cost of a NEW Lycoming. I think this is what experimental aircraft (auto) engines are all about, doing it yourself. The Kit auto engines seem to be too much money, when their performance is not a leap forward. However I do like the powersport Rotary kit engine, which may go back into production, but we are talking about $28,000 for the whole kit, plus (electric) prop ($9,000). Expensive but nice. Van's had an article on this in the RVator a while back.

Obviously he had a re-do, duplicates and boo-boo's in the price list, but may represent this is more like the real cost of a do-it-yourself engine?

Clearly an auto engine, if you do all the labor, represents savings.

As far as rebuild, I think I have said it before, I had 3 Lycomings go over TBO of 2000 hours, knock on valve covers, I hope the forth will do the same.

2000 hours is a long time from now. Compared to fuel, hanger, tax, insurance the $10,000 rebuilds are not a big cost ($5.00/hr), but I agree the auto rebuild will be much cheaper in theory. Of course you have to wait a long time before you realize this savings/cost (10, 15 , 20 years?). In the rebuild equation for an auto engine, does that include the PRSU? Still the auto engine should be much cheaper to rebuild by a factor of 5 to 10 times.

Cheers George

I agree George that for 90% of people who can't turn wrenches on an engine, a Lyc or Lyc clone is the way to go. Bolt it on and go flying. For the other 5-10% who want something different and have the $$, the Egg Sube kits are easy to bolt up and go flying with all the engineering done for you. For the ones who like more of a challenge, Tracy Crook's PSRU, parts and ECUs make installing a Wankel easier at a low cost.

Finally for the very few with the knowledge and skills to engineer the installation, systems and building the engine, you can certainly be flying for under $10,000 firewall forward with an auto engine conversion if, as you correctly point out, don't count your labor.

I have agonized a good 50 hours already on various installation and system problems with our turbo Subaru RV10 project and have yet to cut much metal so far although the airframe is coming along well. Again, the turbos, cooling and intercooling systems present major packaging problems on this airframe compared to an atmo Lyc or even atmo auto engine but I think I have the plan now formulated in my head now. At one point I actually was thinking that this was not going to work out and a 540 was looking pretty good!

For me, this is the essence of experimental aviation but this is certainly not for everybody. Building the airframe is enough for most and a major accomplishment in itself.

Some friendly advice to those contemplating their own engine conversion- be prepared to spend a lot more time getting into the air, and more time testing and solving problems when you do. You will have some setbacks. This is not a project to take lightly. Be patient, use only the best judgement while doing your test flying. Learn from other's experience and mistakes. We want to see you and your creation around for a long time.

I just got to fly my friend's new -7A yesterday with an O-360 and Sensenich fp prop. Worked very well. Takeoff acceleration was not as good as my IVO/ Sube as expected but still very adequate. Ambient was +28C or so the two of us were around 350 lbs. (not each) and 20 gallons of fuel. ROC was around 1200-1400 fpm at 90 knots.

We wound it up straight and level at 7500 feet and saw right around 170 knots TAS. I was pretty impressed. Fuel flows were slightly lower than my Sube at the same speeds. He is a good 10 knoits faster at this altitude than my 6A turbo Sube at my normal power settings.

Vibration was slightly higher and noise levels were similar. We both have extensive soundproofing.

Overall, it worked well and flew well. Simple under the cowling and simple to manage.

hey dan or robert,

you guys done anymore comparison flying since OSH?

Whenever Robert's ready

I've been emailing Robert here and there, asking if he wants to do the side-by-side fuel burn comparison. I guess he's not ready yet. Last I heard, he's putting in yet another engine.

)_( Dan
RV-7 N714D (643 fast, economical, trouble-free hours)
http://www.rvproject.com

dan said:

I've been emailing Robert here and there, asking if he wants to do the side-by-side fuel burn comparison. I guess he's not ready yet. Last I heard, he's putting in yet another engine.

)_( Dan
RV-7 N714D (643 fast, economical, trouble-free hours)
http://www.rvproject.com

Click to expand...

Dan, Robert is doing a lot of research for Eggenfellner and that's why he has done the engine changes. It isn't as if he has had any troubles, which is sort of implied by your post. The Eggenfellner Subaru conversions have proven very reliable. The fact that they are continuing to do research is a GOOD thing, is creates a better alternitive product. I am continually perplexed by the Lyc defense crowd. I think it's a fine engine it should just cost 1/3 as much as it does. Many of the auto-conversion crowd are way too enthustastic about their choices, true. But they are THEIR choices, that are in no way forced to be YOUR choices. I won't be running a Subaru in my aircraft, but I don't worry as much about those who want to since Eggenfellner is providing a good FWF package. I also don't want your Lycoming to break down Dan and I hope it provides you with a easy 2000 hr TBO. General aviation is such a small segment of the population that we need to hang together (or as Ben Franklin once said) we will surely hang seperately. I like to see alternitive engines with the HOPE that somebody can get it right and improve the number of acceptable engines. I don't think blind devotion, (or even well-sighted devotion for that mater), is a wise way to make an engine choice.
Bill Jepson
RotaryRV-10

No implications

I agree completely with everything you're saying. I'm 100% in support of the spirit of development. Didn't mean to imply that he was having trouble with his current (previous) engine setup. BUT -- I do want to observe that maybe all this tinkering is keeping him from doing what a lot of people have been looking forward to seeing -- the side-by-side fuel burn comparison, developing a baseline with one configuration, then moving on to the next. As opposed to a continuous stream of changes.

I would think Robert and others would want to do the baseline comparison before moving on to another powerplant setup. Document it, then move on. Not saying it's not already documented in and of itself, but the type of side-by-side spreadsheet thing I'm talking about will be very interesting for Subaru powerplant customers to look at in helping them make a choice. I think such a thing will definitely help show where exactly the Subaru shines and where it doesn't. This can factor into builders' decisions based on their mission profiles.

I can obviously wait, and I'll just keep flying the crap out of my RV-7 in the meantime!

)_( Dan
RV-7 N714D
http://www.rvproject.com

Rotary10-RV said:

Dan, Robert is doing a lot of research for Eggenfellner and that's why he has done the engine changes. It isn't as if he has had any troubles, which is sort of implied by your post. The Eggenfellner Subaru conversions have proven very reliable. The fact that they are continuing to do research is a GOOD thing, is creates a better alternitive product. I am continually perplexed by the Lyc defense crowd. I think it's a fine engine it should just cost 1/3 as much as it does. Many of the auto-conversion crowd are way too enthustastic about their choices, true. But they are THEIR choices, that are in no way forced to be YOUR choices. I won't be running a Subaru in my aircraft, but I don't worry as much about those who want to since Eggenfellner is providing a good FWF package. I also don't want your Lycoming to break down Dan and I hope it provides you with a easy 2000 hr TBO. General aviation is such a small segment of the population that we need to hang together (or as Ben Franklin once said) we will surely hang seperately. I like to see alternitive engines with the HOPE that somebody can get it right and improve the number of acceptable engines. I don't think blind devotion, (or even well-sighted devotion for that mater), is a wise way to make an engine choice.
Bill Jepson
RotaryRV-10

Click to expand...

Very well stated Bill, whether you have a Lyc RRRRRRRRR, Sube EEEEEEEEE or a rotary HMMMMMMM turning your prop doesn't matter too much as long as we are all up their enjoying flying. And yes, Robert has been very busy lately with testing, setting up a new hangar and just back from Copperstate. I wish I had the time to fly as much as Dan!

rv6ejguy said:

I wish I had the time to fly as much as Dan!

Click to expand...

don't we all!


nice post bill.

nice post dan.

re: Aerosport power and overhauled 360's.

I called them about this very question about 2 weeks ago. Basically they said that they're more than happy to overhaul a 360 core IF you can find one, but the rules have changed in the last few years:

1) 360 cores are nearly impossible to find
2) when you find them they're overpriced
3) by the time you've bought the overpriced 360 and finished with the overhaul, you're only a couple thousand $$$ short of a new engine.

They said that occasionally they do get some 360 cores, but as a rule they just don't get them in like they used to.

FYI: I spoke with them for about 30 minutes. She was very patient, answered all of my questions, and took the time to really explain all the differences between the various engines and options. Totally good experience from beginning to end. I can say the same about Mattituck. They're both just really pleasant companies to deal with. I can't say diddly about their products (others have talked to that at great length), but I know what I'm looking for in a company and those two have it nailed.

-John