# Stinger drives just priced me out of a conversion...

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#### pfarber

##### Well-Known Member
HBA Supporter
Just checked the web site, $5500 for a PSRU in an AC. That would put my auto conversion over$10k.

NOPE.

Time to start looking at airboat engines.

HBA Supporter

#### pfarber

##### Well-Known Member
HBA Supporter
Its the only unit they sell. Airboat use is $3k, E/AB use is$5500. For the exact same part.

My budget was around $3k for a PSRU. This was really the only option. Now with a motor/psru/mods pushing$10k there is no savings over a used certified motor. The only reason I ever considered an car motor was because the initial outlay should have been less than $10k (I figured about$7-8k, but $10k was my limit). Even if a buy a certified core, the cost to put into service would be less than an auto conversion. Unless there are some other$3k PSRUs that I didn't discover?? I doubt there are, but someone may know.

#### BJC

##### Well-Known Member
HBA Supporter
Its the only unit they sell. Airboat use is $3k, E/AB use is$5500. For the exact same part.
I would build a (flying) boat.

BJC

#### pfarber

##### Well-Known Member
HBA Supporter
I would build a (flying) boat.

BJC
Yeah but then I support a company that pulls nonsense like this. Maybe if the PRSU has SOMETHING to differentiate it, extra NDT, premium parts, anything to justify a $2k increase. #### Aviacs ##### Well-Known Member Any known examples in flying airplanes? Looks like they are for large engines? Link i used did not show option for aviation use, have to look harder later. smt #### ScaleBirdsScott ##### Well-Known Member The fact it's for an E/AB may just be seen as extra headache on the part of the sales and support side of the equation. I gotta imagine most guys strapping an engine to the frame on an airboat have very few questions. Or if they do, few are for the people making the engine or parts. It'll be some hours in a boat shed wrenchin' till it works. They're guys out there getting in hard hours on their machine and are just workin' on it. Meanwhile the people anticipating that engine putting them in the air better make sure they've crossed all those i's and dotted all of the t's before they take to the skies and that may historically have led to customers that expect a much higher standard, who ask more questions, need more assurances and hand holding, and generally are not the sort of guy out there crankin' on stuff until it looks right, but someone who may or may not know their way around the engine bay more than where the oil goes, and have ventured out on some experience to build an airplane. So, call it discrimination or whatever, but I can easily imagine the the price is higher just due to all of that. #### Victor Bravo ##### Well-Known Member I still didn't see a clear answer to what engine and what airframe he's talking about... this is a redrive for a Tee Dee. 049 on the Cox PT-19... right? I understand it's the only redrive they sell, and I understand that they have two different prices for the same unit. Their insurance cost on the ones they sell for airboats is probably five times less than what their insurance cost is for the same one sold for E-AB airplanes. EDIT: 10 minutes later... this is absolutely amazing. I went to the Stinger Drives website, and THEY don't say what engines or airframes this product is for. There's nothing that mentions any type of aircraft either. So besides pfarber above, even the company itself doesn't want anyone to know what their product is for, what it fits, or what the value proposition is. Last edited: #### pfarber ##### Well-Known Member HBA Supporter But they also have a unit specifically for aircraft. So its either a better unit, or simply a money grab. I'm not going to lie to get a cheaper price. I have other options. I hope they have enough airboat sales to keep them running. Ballistic drives is also on my list, but no emails were returned when I asked for information. #### pfarber ##### Well-Known Member HBA Supporter I still didn't see a clear answer to what engine and what airframe he's talking about... this is a redrive for a Tee Dee. 049 on the Cox PT-19... right? I understand it's the only redrive they sell, and I understand that they have two different prices for the same unit. Their insurance cost on the ones they sell for airboats is probably five times what their insurance cost is for the same one sold for E-AB airplanes. EDIT: 10 minutes later... this is absolutely amazing. I went to the Stinger Drives website, and THEY don't say what engines or airframes this product is for. There's nothing that mentions any type of aircraft either. So besides pfarber above, even the company itself doesn't want anyone to know what their product is for, what it fits, or what the value proposition is. I read a few reviews and the mount will work for standard chevy/ford bellhousings. Stinger does have distributors... but none of them seem to specifically point out AC use. Here's a stinger on an LS3. That's some HP to handle. I don't think these units are whimpy... but at$5k its just out of my budget.

http://www.aerotechllc.net/ls3-aircraft-engine.html

The site makes this statement:

They have thousands of these boxes out in the field, from airplanes to airboats. Although the airplane gear box has been modified with specially cut gears from their original tried and true, all their gears have been highly machined. The gear design that we use holds up to the tractor configuration. Stinger has also added chip and temperature sensing for your comfort. Other companies have not taken the time to redesign their gears for this airplane setup. This creates a harmonic imbalance, high thrust loads on bearings and an unsafe situation.

Not sure if that's $2k worth of upgrades. Here's a stinger on an LS3. That's some HP to handle. I don't think these units are whimpy... but at$5k its just out of my budget.

Looking at $2k for an engine core,$5k for a PSRU, $2k for a motor mount and radiator and add on$1-2k for 'stuff'. Even at a very budget built you're at $10k. This is used certified motor range... and the certified motor would just bolt right up on the first try. The only reason I even considered a car motor was cost. But at this point I can't see a 180-200hp car motor installed for less than a used 360. Last edited: #### TFF ##### Well-Known Member I think you are lucky you are having a reality check. If you have ever been around airboats, there are some nice professional boats that are out there. Most are home conversions, that shall we say, are farmer engineering at its best, with as much rusty angle iron to make a junk dealer jealous. Those guys whine about the price, but they don’t whine about installing. The only real reason to go auto conversion is because you want to be different. The only people that an auto conversion is cheaper are the ones who can machine their own redrive ,but find it cheaper to buy someone else’s time than do it themselves. Someone who can build their own EFI but want to use that talent on their ham radio. People who just want to hot rod an engine or just want to experience the process of an auto engine plane. Even at buying everything at$10k probably has another $5k of learning curve. They are not consumer engines; they are hobbyist engines. It’s like owning a race car. One week you make all the laps, but some times down the road you will not have to change the oil because there is a big hole in the side. It’s not the place for someone who wants to just fly. Hobbyists want to play with their toys. A conservative pilot wants to forget there is any mechanical necessity associated with them flying. They are just diametrically opposed positions. #### pfarber ##### Well-Known Member HBA Supporter I think you are lucky you are having a reality check. If you have ever been around airboats, there are some nice professional boats that are out there. Most are home conversions, that shall we say, are farmer engineering at its best, with as much rusty angle iron to make a junk dealer jealous. Those guys whine about the price, but they don’t whine about installing. The only real reason to go auto conversion is because you want to be different. The only people that an auto conversion is cheaper are the ones who can machine their own redrive ,but find it cheaper to buy someone else’s time than do it themselves. Someone who can build their own EFI but want to use that talent on their ham radio. People who just want to hot rod an engine or just want to experience the process of an auto engine plane. Even at buying everything at$10k probably has another $5k of learning curve. They are not consumer engines; they are hobbyist engines. It’s like owning a race car. One week you make all the laps, but some times down the road you will not have to change the oil because there is a big hole in the side. It’s not the place for someone who wants to just fly. Hobbyists want to play with their toys. A conservative pilot wants to forget there is any mechanical necessity associated with them flying. They are just diametrically opposed positions. I am 100% into the 'do my own thing' and 'hobbyist' mentality. I have restored antique vehicles and also made parts unique to a specific truck that sold worldwide. I'm convinced that an auto engine would work with a modest amount of ECU programming.. its done all the time in the race world. Not saying that every idea they have is a winner.. but they run 100LL, have stand alone ECUs, and reprogram them. For me its simply cost. I agree that even with$10k of parts, there's still going to be a few grand of 'learnin' to do as even though I have read and examine everything I can find, its still new territory.

But the PSRU costing an additional $2k just crossed the line. I set a budget, and its over. I have nothing against auto engines, PSRUs, and tinkering. When I find a good IO-360 core I will rebuild it myself and test run it. I may still get to that$10k mark.. but there are simply a lot less unknowns. No radiators, not fabbing a cowl, no welding a mount.

The E/AB desperately needs a 180-200hp FWF kit that doesn't cost $50k. Look at the Corvair folks, strong community and a solution to a problem. But sadly not in the HP range for a 4 place high speed XC machine. And if I learned anything from this forum (well, I learned many things) is that I wouldn't want to deal with 'the public' as even a group of people who actually want to convert auto's are more trouble than they are worth. #### BJC ##### Well-Known Member HBA Supporter The E/AB desperately needs a 180-200hp FWF kit that doesn't cost$50k.
You are correct, there is a need.

And if I learned anything from this forum (well, I learned many things) is that I wouldn't want to deal with 'the public' as even a group of people who actually want to convert auto's are more trouble than they are worth.
Same here. Unfortunately, the E-AB world is full of people who are ready to tell others what they should be doing, who expect of others what they are unwilling or unable to do themselves, and who believe that something complicated should be easy.

BJC

#### pfarber

##### Well-Known Member
HBA Supporter
You are correct, there is a need.

Same here. Unfortunately, the E-AB world is full of people who are ready to tell others what they should be doing, who expect of others what they are unwilling or unable to do themselves, and who believe that something complicated should be easy.

BJC
I have hippopotamus thick skin. I was in the Navy (Submarines), a Corrections officer, and owned an ISP dealing with 1000's of customers. But even on this forum I've been emailed and warned about dealing with 'old heads' who I properly called out for their BS. But hey, this is a kid safe zone lol.

I'd be more than happy to talk and come up with ideas.. but this is just not seem to be the place to do it. I with held supporting membership because of it. I run a site to, and there were many, many great battles.. the engine color debates, the proper screw head war of 2007, and many other great debates (of varying intensity) so I know moderation of a board can be a time suck.

But the real issue for me is money. I have $3k in an airframe. My goal is up to$10k for an engine. That's my no-go line. And the budget is shot. Can't do it with a car motor. Buying used PRSU's doesn't seem to be a thing (is there??? Anyone know of a used stinger on the market??)

But when I see core/prop strike IO-360s for $5k I am much more willing to gamble on rebuilding them.. the core value is still there, and I can get lucky and get used parts that pass inspection. And then I'm in 'it just bolts up and works' territory. Not as fun or sexy as saying I have a car motor out front. #### Victor Bravo ##### Well-Known Member Is this engine/redrive combo intended for the BD-4 that is in your signature file??? I've heard of BD-4's with auto conversions. Don't know about a BD-4 with anything the size of what is shown on those websites in the posts above though. #### Dana ##### Super Moderator Staff member The E/AB desperately needs a 180-200hp FWF kit that doesn't cost$50k. Look at the Corvair folks, strong community and a solution to a problem. But sadly not in the HP range for a 4 place high speed XC machine.
The fact that it doesn't exist would indicate that it's not an easy thing to do.

#### xrfred

##### New Member
Aeromomentum sells just the redrive
Might be worth looking in to

#### pfarber

##### Well-Known Member
HBA Supporter
Is this engine/redrive combo intended for the BD-4 that is in your signature file??? I've heard of BD-4's with auto conversions. Don't know about a BD-4 with anything the size of what is shown on those websites in the posts above though.
Yes, there is (was) a BD-4 flying with a V8.. but it was more of a custom race engine than an off the shelf motor. This was done to get an all aluminum motor installed. Ran well, had the typical cooling problems. This example was well over $15k. 180-200HP fits my mission profile - 4 place high speed XC. I'd live with 150hp O-320 for the right price, but I would rather be closer to 200mph than 150mph. #### pfarber ##### Well-Known Member HBA Supporter The fact that it doesn't exist would indicate that it's not an easy thing to do. The price point is the issue. As soon as you look for FWF packages they all seem to want$20k+. When you can get a certified motor for less.. why mess with a conversion?

The only reason I considered autos: cheaper install price. Note: on high HP engines autos are still the clear winner.. but the need for 400+hp motors is tiny compared to the need for a sub 200hp powerplant.

But now that there are no affordable (again, my cut off is $10k) packages, why mess with it? Its not that auto conversions don't work. They do. But there are no tangible benefits. Before I could rationalize the extra weight/work with a large savings on initial install. Say$5k-$7k. Now that's not viable. I cannot come up with an install for less than$10k, and I still need to iron it out.

I'll still keep an eye on the auto conversions... but I don't see a realistic solution. The key was a \$2-3k PRSU.

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