View Full Version : Radial or Opposed?

11-14-2004, 10:58 AM
Am trying to choose a powerplant for my PA-18 experimental project. I'm thinking either a plain vanilla O-320 or a Rotec radial. www.rotecradialengines.com the rotec only puts out 110 Hp but claims that with the added torque of a radial it performs more like 140hp and it does it at about 6gph.

Price is of course a factor here. What can I expect to pay for a descent O-320 including all of the accessories. The selling price of the Rotec is $12,500 including ignition system, alternator, starter, and carb. That seems like a lot of engine for the price.

Any wisdom is appreciated.


11-14-2004, 11:46 AM
by all means, go with the radial!! We already know how a plain vanilla 0-320 performs in a Supercub. This way you'll get to be our guini er ginni er gineau er tester. :D

11-14-2004, 11:59 AM
I think the radial would be very cool, kind of like the old Faust PA-12. I would be very interested in seeing the performance results. Getting it cowled appropriately may be the most interesting aspect. What is the weight difference between the two? Good luck.

11-14-2004, 12:11 PM
I corresponded with the first importer, Brian Henneman, about 18 mos. ago, its about 220 lbs. Since then, they have come up with a nice collector ring. They have done several batches of motors and always sell what they bring to Oshkosh. I'm going to give them 2 more years, and then buy one for my Renegade biplane. Don

mit greb
11-14-2004, 01:43 PM
Put a 985 on it! :o Now that would be something! :onfire:

11-14-2004, 03:07 PM
You would have to be careful with a 985 on runup to keep the torque from flipping ya over.

11-14-2004, 05:51 PM
Well, even though I think the Rotec radial is cute, and appears well made, I wouldn't go that route. Have you thought how hard parts would be to get? If you blow a jug in the middle of nowhere, you are stuck. In addition, with only a handful of engines now running, are you sure you want your life riding on its reliability?
For my money, I'd buy a XP-320 or XP-360. They are comparitively cheap, and all of their parts come from the same exact bins as the certified engines do. Their reliability has certainly been proven, and there are lots of parts out there for them.


11-14-2004, 07:30 PM
Last time I checked those XP engines were around $20K :o

11-14-2004, 07:59 PM
Last time I checked ECI's 320 engine was 11,500 so up and running would be in the 15K range depending on accessories. 360 kit would be closer to 20K depending out who's kit and accessories.


11-14-2004, 08:20 PM
Do you have a web site for the eci? I would like to look into that.

11-14-2004, 08:36 PM

11-14-2004, 08:55 PM
I would go with a Lycoming type powerplant of somekind. You have enough work building the airplane. My father inlaw is building a Bushmaster with a car engine of somekind and it set him back 10 years figuring it out. Since your in Sioux Falls you should contact Bob Smelser, he built a PA18 from scratch a few years ago and it won an award at OSH. He keeps it in Brandon on a farm.

11-14-2004, 09:28 PM

If that's the Cub clone that's at Marks, it is quite nice.

11-14-2004, 09:55 PM
Yep, thats the one.

11-15-2004, 05:13 PM
With only 172 cubic inch displacement, I don't see how it would have the torque of a 320 cubic inch O-320-150. Also with a TBO of only 1000 hours, where is the savings. Manufactured "down under", I bet parts are going to be hard to get. The engine is the second most important part of the plane, don't skimp. Go with something that is proven. Crash

Frank T
11-15-2004, 07:13 PM
That little radial looks and sounds real cool...but I agree...I'd go with an O320/360 clone or OEM.

What do you think one of those radials will be worth used with 50 hrs on it, vs an O-320/360?


11-15-2004, 10:27 PM
the rotec has a 1.6 planetary reduction in the nose, so they can claim a bunch of torque, but its still only 110 hp. And the parts.... I'm seriously thinking of putting one in my local joyriding exp bipe, because they seem to be a perfectly good motor (compared to the go-kart, motorcycle, lawn mower and snowmobile motors I have trusted my butt to in the past) but..... I'm also thinking about an SC and there's no way I would ruin a perfectly good widely supported tool with a handmade motor from such a small outfit. If I build or buy an SC, I'll be dreaming of flying it to AK someday. But I'd never dare to with a boutique exp motor. I picture myself sitting in some remote FBO with some minor valvetrain problem. It wouldn't take much. It wouldn't have to be dangerous. I've already talked myself out of it without picturing a crank failing over an endless forest. Don

11-21-2004, 07:13 PM
Thanks everyone for your input. Some of those points I did not consider. Fortunately I have some time to make up my mind. So far I'm in the process of welding up the fuse.

11-21-2004, 09:52 PM
There used to be a PA-12 that sat on Philo's strip in Wasilla (Alaska) that had a radial engine. I remember being told it was an STC installation. Warner rings a bell. Any Alaska guys remember that plane?


11-22-2004, 10:09 AM
Faust PA12, has a 165 Warner. Its in Bozeman MT now.

12-06-2004, 07:00 PM
Has anybody looked into using the 125HP Franklin motor?

12-07-2004, 10:49 AM
I am a Rotec dealer here in Michigan. We have motors and parts here in stock. The price of the motor in Australia is $12500 but it takes allot of time and money to get one here. We are putting them on J-3 frames with Sensenich propellers amphib floats. Great engine all the way around. Can't beat the price now but it's going up. Contact me anytime if you have any questions or want to see one run. We currently have some spares on Ebay.


12-08-2004, 08:43 PM
I would love to see one in person. If you ever get around to the Sioux Falls area look me up. E-mail is storm_pilot@hotmail.com