# AutoPRSUs engine discussion

Discussion in 'General Auto Conversion Discussion' started by pfarber, Aug 29, 2019.

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1. Aug 29, 2019

### pfarber

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They mainly sell a $15k PSRU but also offer a FWF package in the$40k range

I'm surprised to see many of the same faults. I'll time code the video since it jumps around

On the clutch at 7:56 the bolts are flush with the nuts, not locking mechanism visible. None of the nuts/bolts appear to have locking mechanisms

At 8:22 he talks about the starter size. Um... geared starters are a thing. OK, not a real issue but 'salesmanship'??

0:48 at the bottom there is a container (yellow) with a hose. Hose not secured with a clamp.

0:57 white K&N filter (for PSRU? Engine?) not lock wired, nor does there appear to be a method to wire it.

Overall no safety wires. Most of the bolts appear to be the proper length, but I see some lock washers against aluminum. They need a steel washer under them. Note that the prop governer IS PROPERLY LOCK WIRED. Most likely because its a certified unit and its required. But the rest of the $40k motor? NOPE. One one piece of lock wire anywhere. This is a HUUUUGGGEEE tell for me. They bolt a certified part to the E/AB motor and INSTANTLY you can tell that its done to a much higher standard. BBUUUTTTT at 2:27 they show a close up of the governer. You can see the actuation cable..they went with a jamb nut. HARD FAIL. Read AC 20-71: 6. DUAL LOCKING DEVICE. A dual locking device on a fastener consists of any two separate locking features described in paragraph 5. (note jamb nuts are not listed) 7. BOLTS SUBJECT TO ROTATION. A bolt is considered to be subject to rotation ·if it serves as an axis of rotation producing relative motion between the bolt and one or more components attached to the bolt. e. Bolts which are subject to rotation must have at least one nonfriction-type lock. The other lock, if dual locks are required, may be either a friction or nonfriction-type lock. If they replaced one of the jamb nuts with a self locking nut (a$.15 part) they are golden.

3:22 The upper radiator hose. I get that they don't have a molded custom hose, but that splice in the middle with hose clamps... who wants to bet that the metal insert is not properly beaded for hose retention?

3:24 on the firewall, there is a hose fitting that bothers me (its red and blue) on the firewall.. but its probably for the test stand.. but still... its a tell that they are not thinking up to certified AC standards.

I did like that they went to with AN fittings for hoses and cable clamps were properly insulated. These two items, out of a $40k motor are the only aircraft level of build I can see. And if they charge$15k for the gearbox, that's a $25k motor (lol really? For an LS3?.. sorry, I digress) without any of the proven techniques of airplane maintenance/construction. Again, I have NOTHING against AutoPSRUs, I'm just looking for 'best practices' from companies with products out there to compare them against certified engine best practices. 2. Aug 29, 2019 ### TFF ### TFF #### Well-Known Member Joined: Apr 28, 2010 Messages: 11,903 Likes Received: 3,402 Location: Memphis, TN Bombardier missed lots of safety wire on new CRJ200s on engine installations. It’s going to be rare to find what you are after, I believe. The auto engine people come from a different direction. Many seem to have never seen a Lycoming or Continental installed. They have already run away because of the price to roll their own. They just have no experience. At least as owner operators. It’s a broad statement, I know, but seems to be true. The installations that are good, are massaged by the builders. Renting a 172 was probably as close as they got. 3. Aug 29, 2019 ### rv6ejguy ### rv6ejguy #### Well-Known Member Joined: Jun 26, 2012 Messages: 3,749 Likes Received: 2,812 Location: Calgary, Alberta, Canada Counterpoint. You have to remember that most auto engines don't shake like a Lycoming and while those certified engines have hundreds of millions of hours collectively on them, auto engines have trillions. I haven't seen anything fall of any of my cars for the last 20 years. I only have lock wire on 3 turbo bolts on my aircraft. Nothing has fallen off in the last 16 years. The auto OEMs can't and don't have bolts and nuts falling off their cars and there is no lock wire on anything. Proof is in the pudding. There are minimal cotter pins used on modern cars and Stover and tab and slot type lock nuts are in places where they are deemed necessary. Works very well. I know A&Ps can rack up the hours lock wiring stuff on a plane or engine but I don't want to be wasting my hours on that stuff. Just because lock wiring is common on certified aircraft, doesn't mean it's applicable or better on auto conversions in aircraft. Con rod nuts are REALLY critical I think you'd agree but they are not lock wired, cotter pinned or generally use any type of locking nuts. Ditto with oil drain plugs. wsimpso1, Himat and spaschke like this. 4. Aug 29, 2019 ### pfarber ### pfarber #### Well-Known Member Joined: Feb 21, 2019 Messages: 389 Likes Received: 26 Location: Pennsylvania "Just because lock wiring is common on certified aircraft, doesn't mean it's applicable or better on auto conversions in aircraft." But these additional measure are BEST PRACTICES. And there are very good reasons for it. Cars and AC live in different worlds of preventative maintenance. A car motor goes 100k before you have to do anything to it (other than oil). An AC engine may go a few 100 hours before it is tested/inspected. If you fly ZERO hours, that annual condition inspection is going to look over the motor. This all comes down to if a car motor breaks, you pull off the road. An AN motor breaks, not so much. Look at race engines. They do many of the things that certified engines do. Why? I mean a NASCAR motor will run at most 3 hours? A drag motor 5 minutes? And they still go the extra step of lock wires, thread lock etc etc. Not because Threadlocker Red is going to make 1 more HP, but because that bolt NEEDS to stay put. And really, if you pay$35k for a car engine and all you get is a car engine, not even up to the best practices of certified motors, isn't that insane? I mean auto conversions have had a crappy past. Yes, a few lucky ones 'made it' but a car motor is 1/10th the cost of an certified motor yet their implementations fail left and right. Its not the basic engine design, but the implementation of the motor in the airframe.

Cotter pins are used in suspension all the time, when needed. They also use OTHER locking methods like Torque to Yield bolts and nuts. My Equinox does not use cotter pins on the CV shafts, they are held into the hub with one time use torque to yield nuts. So while safety wire may not be used, there ARE locking methods employed when needed.

And we can agree that the FAA simply holds AC to a much higher level of preventative maintenance. Do you preflight your car EVERY day? When was the last time you checked the oil? Or do you just wait for the oil light?

I think, that an engine that is being sold for aircraft use, or even being a one-off conversion, should be held to the higher standard the FAA requires. Its it more work? I can't see lockwiring an engine to be more than an hours time. Even if you just to the drain bolts, filters and bolts without locking mechanisms.

Its just not that much to ask when the flip side is a dead motor when airborne.

5. Aug 29, 2019

### TFF

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I also think you are missing the cowboy effect. A lot, not all, who do auto engines are giving the middle finger to Lycoming; that is why they are doing it. Its really the wrong reason. Auto engine people can tend to be outer rim of how they want the maint done. They tend to want less, like less government. Their belief is they dont need it or want it, and they defiantly dont want certified standards. The US graciously allows it. Being a consumer who fought to keep an Aerostar in the air is not where these people are comming from. Think too cheap to overhaul a C-65 and you hit the target audience. A few gear heads, but most seems to be against the man. Its like the build or fly analogy, build an auto engine because you want to do an auto engine. Also if you think about it and you have to love them, because anyone selling an auto engine conversion as a business really needs to be examained in the head. Its a joke, kind of.

6. Aug 29, 2019

### pfarber

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For me the failure of auto conversions is similar to what you said. The people that do it really don't put out a 'how to'. Their conversion is a family secret now.

I will give props to rv6ejguy for posting alot of what he did with his radiator. He did validate the Meredith effect of his install, and I'm sure he's a busy guy, but who wouldn't pay $5 for an in depth article about the design, construction and results? I would. I've been trying to get back issues of Contact! magazine but they 'editor' is just not making any effort to fulfill back issue orders. I'm not giving the finger to Cont/Lyc. I'd buy one in a heartbeat if I could afford it. But the prices they ask are just not based in reality. I can get a custom forged crankshaft for$2k. Yet a crank with a Lycoming PN is magically $8k? They just don't care about growing the market. Even the 'experimental' versions of certified motors are what,$5k less? really?

Conversions are like real estate. You make the money at the buy. Shave $25k-$30k off the cost of an engine and even if you have more scheduled maintenance, the parts are low cost, readily available and last a long time.

I said above that rarely does an auto engine fail. It's the implementation of that engine in the airframe that fails. But if you step up the install game... think it through and adhere to best practices.. build off of proven designs you should increase the odds of a successful install.

My airframe cost me $3k. I think I can get an engine and avionics done for less than$10. The world needs more $15k airplanes. 7. Aug 29, 2019 ### rv6ejguy ### rv6ejguy #### Well-Known Member Joined: Jun 26, 2012 Messages: 3,749 Likes Received: 2,812 Location: Calgary, Alberta, Canada I think many people considering an auto engine lack the knowledge to make a good judgement on how it could turn out. Too many have stars in their eyes. The smart folks know that the benchmark is a Lycoming or Continental. We have guys like Ray Watson who's planning to manufacture LS conversions. He bases that on 3 years of flying his successfully. I think it could succeed. Time will tell. Aero Momentum is doing things right. The VW companies have been successful for many years. Do it right and it's a viable business. Even Viking with their questionable past is selling lots of engines, whether they last a long time, we don't know yet. Last edited: Aug 29, 2019 wsimpso1 likes this. 8. Aug 29, 2019 ### pfarber ### pfarber #### Well-Known Member Joined: Feb 21, 2019 Messages: 389 Likes Received: 26 Location: Pennsylvania Yes but the world sorta runs off 150-200hp motors. That's the HP you need for a decent xcountry 4 place plane. Sure, you do so a sonex or some other tiny VW two place.. but in reality you have a one place plane that isn't really xcountry ready. An LS conversion? Its already done (see the first post of this thread). Now make it$10k with a PSRU and you have something. Another $50k car motor is not what the market needs. As for the Moose mods? I would take another look at some of the hoses and routings. Also safety fastners and lock wire. Its a$50k motor you put in an AC, it should follow the same practices as one.

9. Aug 29, 2019

### Himat

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Or if you check when the A&P “Best practice” started it may be that it was, not is best practice. The Lycoming/Continental engines design dates from the 1950’ies to 1960’ies. Now, oil change in a 1960’ies car was every 5000km? (In miles maybe 3000?) Rebuilds before 100k miles was not that uncommon either.

A different explanation than the operation conditions could be the design and build standard of a modern-day auto engine.

10. Aug 30, 2019

### TFF

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People like Ross are exactly who should be doing a conversion. Versed enough to know it’s not a free ride. VW fits very well. Any LS or like that is not destine for a mini warbird gives me suspect when there are plenty of Continental 470s with life at a reasonable cost compared to a V8 conversion.
If you knew me closer, you would think I would be the first to go V8. Be the defender of auto engines. I actually think it would be fun to have one. The way I see it is if you can not touch every part and correct defects and are willing to do such, auto is a bad idea. You don’t know what any failure point will be. Ignition wire to crankcase. Headbolt to drive gears. Some systems have better success, but none are equal in testing to certified. I’m not blind that Lycoming don’t break. I make a living fixing them, but if you want blind bliss of operation, come on. It’s not going to be auto. If you are fascinated by being apart of the chain of operation, auto is perfect. I have an aquatint that had a twin with two Blanton V6s. Not my choice. First engine failure was hour 2. He had a few more. He had engine and drive problems. He was a perfect auto engine owner, he loved the challenge. He sold his plane a couple of years ago. He kept the engines as the new owner put two Lycomings on it. It really made the difference of becoming useable vs a project. He bought a Velocity with an airplane engine.

11. Aug 30, 2019

### rv6ejguy

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The Blanton V6 conversions were crap. Tons of things done wrong to the knowledgeable eye and so many other conversions are equally so. Don't blame failures on the basic mechanicals when lay people are involved in the process.

As I said in another thread, there have been numerous successful auto conversions like Russell Sherwood's Glasair, Reg Clarke's Dragonfly, Gordon Wardstrom's Bearhawk, Jeff Akland's P-85, Ray Watson's Moose, approximately 500 Subaru EJ powered RAF 2000 gyrocopters, Gordon Shirley's glider tug LS Pawnee (replaced the troublesome 540 Lyc), Robinson SeaBee, Gary Spencer LongEZ . The list is a lot longer of course.

These show that they work just fine IF done correctly. You can't blame the engine when things are done wrong by the guy designing the other parts or doing the wrenching.Tarring all auto conversions with the same brush because of failures you know about is unfair.

OEMs like Hyundai/ Kia and most others today exceed the FAA required testing done to certify aircraft engines:

Auto engine design really started to improve in the mid '80s because the OEMs were applying newer technology like CFD studies on coolant, air and combustion areas and really stepped up torture testing levels while going after lighter engine weights.

Last edited: Aug 30, 2019
12. Aug 30, 2019

### ScaleBirdsScott

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If there was suddenly demand for 1,000 high-powered auto-conversion engines a year, you would see a complete LS conversion down below $30k in months. But since there's no big market for 450hp experimental aircraft engines based on a LS crate, even at$30k, even if you started selling them tomorrow at that price, the demand would never meet the supply needed to recover those costs.

Since it seems like the actual market is like 2-5 per year at current prices; and maybe would be, I don't know, 50 that would actually shell out for a $30,000 LS engine every year for the forseeable future; lets be generous and say that you setup a factory for capacity of 50-100 engines a year @ 30k USD standard price per engine, negating add ons and other options, and it takes 3 years to reach the target minimum 50/year volume... how much does it cost to keep running and how much was spent in R&D and facilities to produce them? How much margin is there to pay that off when volume is low? I can see if someone was willing to put money in up front, wait out a tumultuous and potentially long-winded ramp-up phase, and could work with some airframe kit makers or create a demand for the product, that eventually there might open up an option for such an engine to exist on the market at a reasonable cost. I've considered it because of the nature of what I've been designing for an aircraft, that someday it would be nice to have a V8 or similar that was at an attractive price point with good engineering behind the entire package. In the meantime, this AutoPSRU option is an option that I've been following with some interest though not particularly recently. 13. Aug 30, 2019 ### TFF ### TFF #### Well-Known Member Joined: Apr 28, 2010 Messages: 11,903 Likes Received: 3,402 Location: Memphis, TN Successful; I'm agreeing with you. How many of those bolted and went? None. All owners took the special care to make it work. The slap a FWF kit from Vans on anyone of them is not possible, which is closer to what the point of this thread is. Who makes something certified quality like a Lycoming where you don't have to think about the engine but hooking it up. Like I said, it takes someone like you, or hire someone like you to make it work. Did not say it will not work. Most people think a Lycoming is like a Swiss Watch when it really is a B&S. proppastie likes this. 14. Aug 30, 2019 ### pfarber ### pfarber #### Well-Known Member Joined: Feb 21, 2019 Messages: 389 Likes Received: 26 Location: Pennsylvania I'm not bashing certified or auto conversion. But while there are a FEW successful auto conversions most fail. 80%, 90%? These auto conversions are literally just the same old car motor in an airplane. Your only real addition is a PSRU, and those don't cost$15k (you can pay that much, but that's not what they cost).

So how do you increase the viability of a conversion? Well the motor and PSRU are are what they are. The units out there work, and work well. I would say that one possible way is to follow the best practices of motors that DO work well. Those need to be installed/built to a higher standard.

You can find a reg or rule for every part of an AC motor. How often you have to tie a harness, proper bolt length, how many washers to use, when you can't use a washer, certain parts need special or double locking mechanism etc etc. The throttle cable in my car is a plastic ball that snaps into a plastic retention device. Would you trust that in an E/AB? I wouldn't. Certified engines go far beyond this with specific requirements to keep it in place. A FWF package that costs $40k should have a robust, fault tolerant way to keep the **** throttle cable connected to the **** throttle body. Its literally$0.50 to do it right.

I think that by learning the good, and the bad, these things can be avoided. I am not a backyard bubba. My life, and the life of my wife/family/friends etc will be at stake when I ask a conversion motor to pull us into the sky. And my main goal is to learn as many of the best practices to keep the motor running.

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15. Aug 30, 2019

### rv6ejguy

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I think Aeromomentum and Moose Mods are working towards properly developed bolt on FWF auto engine packages which is how you sell real numbers. We'll see in 5 years whether they make the grade.

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16. Aug 30, 2019

### Winginitt

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An engine doesn't know what its in or attached to. I continually read about how an auto engine won't work properly in an airplane yet there are lots of successful examples of just that kind of thing. Something as simple as a Model T ford engine can be made to power an airplane, and many have. Steve Wittman built his Olds powered version almost seventy years ago, and even won races with it.

Now here we are these many decades later, with abundant data at our fingertips, machines that can produce parts automatically, flying examples easily found........and yet we still have people bemoaning the fact that some people really want to do things like this.....not just because of financial considerations, but because they believe in themselves enough to try.
When these individuals are successful, they often exceed performance of standard aero engine installations. Usually the people who are very successful with conversions are the people who show a willingness to work thru problems rather than the ones continually referenced by naysayers as willing to spend money to have someone else solve the problems for them and just throw money at the "bolt in conversion". We need to get away from the idea that conversions have to "only" be something you

Yep, there are people who are willing to try instead of buy.....

Last edited: Aug 30, 2019
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17. Aug 31, 2019

### Dan Thomas

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No, the Tailwind design might be 70 years old, but the Olds didn't get installed until 1974.

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18. Aug 31, 2019

### Dan Thomas

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How many Lycoming cranks are made every year? How many small-block Chev cranks are made every year? There's one factor for you.

What happens when that Chev crank breaks? You coast to the side of the highway, and maybe Chev will give you a new crank. What happens when your Lyc crank breaks? Lyc gets sued for a LOT of money. So they have to buy lots of insurance. There's another factor.

Is that Chev crank nitrided? Don't think so. One more factor.

A homebuilder gets the Lyc crank cheaper because he assumes all the liability by building the engine. Gets a lot harder for the estate to sue Lyc when the guy kills himself behind an engine he built himself.

Nothing magic about it. Low volume, huge risk, extra manufacturing processes. They all add up.

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19. Aug 31, 2019

### Winginitt

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Winginitt Quote: . Steve Wittman built his Olds powered version almost seventy years ago, and even won races with it.

Dan Thomas: No, the Tailwind design might be 70 years old, but the Olds didn't get installed until 1974.

Winginitt Reply: Yes, you are correct. I believe he upgraded from an O-320 Lycoming because it wasn't providing the performance he desired. If memory serves/fails me again, I believe he set some speed records with the olds. However, the technology of using auto engines to successfully power airplanes actually predates Wittmans Olds conversion. Model A Ford engines were used successfully to power Pietenpols. Don't know of any earlier engines, but almost a century (90 yrs) ago someone was able to figure out how to make a crude cast iron engine work in an airplane. Today with lighter, more refined, and more powerful engines, the technological improvements seem to present the biggest impediment.If a Model A engine can provide successful flight, then there is no reason just about any decent auto engine built today should not be usable.

The thread question though is NOT about engines but about PSRUs. (or the lack of them) Lets not drift the thread away from that type of info............I'd really like to see stuff about drive systems of any type.

Last edited: Aug 31, 2019
20. Aug 31, 2019

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