I'm wondering what is the best engines everyone is installing or running? Also the pros and cons? I am building the Zenith CH 650 and have just started. I like the UL350iS or the Lycoming 233 but I see quite a few Corvair engines out there, so what are the pros and cons about them. I do not like the Rotax. I want something simple. So any input will be greatly appreciate.

Views: 11397

Reply to This

Replies to This Discussion

I'm very happy with my Jabiru 3300! It's a dirt-simple, 6 cylinder, direct drive engine with 120 hp and only weighs about 180 lbs with all the accessories attached. Jab's are much-maligned as far as reliability and difficult to cool, but I think that's ancient history. Admittedly, the company probably did beta-testing on its early customers, but they've done dozens and dozens of progressive technical improvements over the years and the last few years seem to have a mature, reliable engine. I've got about 3+ years and 360+ hrs on mine with no major problems - and that's installed in a STOL 750 high-drag, low speed airframe. A Jab would work well with the 650's higher speeds - 6 cylinder engines like lots of cooling air and the faster the better!  Last time I checked, it was still a sub-20 thousand dollar engine, so it's quite a bang for the buck. Jabiru USA in Shelbyville, TN is the dealer/distributor.

CAMit, another Australian firm, actually manufactures the Jab engine to Jabiru's specifications. Oddly, they make their own version which is virtually identical except it has even more improvements and I understand is quite cost-competitive vs the Jab. They've just recently developed a US distributor, so no track history there but the factory is quite responsive to information and parts requests. In fact, I buy some of my parts direct from CAMit as most are interchangeable with the Jab's parts.

Just two of many options out there - that's what's so great about Zenith aircraft - youi're not restricted to any one engine!



How do you keep the CHT down?  I have tried just about everything and they still run too hot.  They are all running about the same, but they are just about cooking.

Search the forums and you'll find numerous posts, but in summary, my installation has an extended lip on the cowl (Jab USA has a new design cowl now to eliminate this), ramp inlets, meticulous sealing of ram air ducts, end-plate baffles between cylinders to keep air from leaking out, "butterfly" baffles under the cylinders, and an extended baffle around the back side of #5 (which is usually the hottest.) I actually had really good temps before the butterfly baffles and ramp inlets, but it has become a sort of mind-game with me to see just how low and how balanced I can get the temps.

I don't want to creep the thread further with details, so don't hesitate to send me a message and I'd be glad help out any way I can!


I have a Corvair engine with a Warp prop and it is acceptable. If I had to do it over I would install the 130 horsepower Viking for less money, lighter weight, newer technology. That is my two cents worth. Had an 0-200 in my Long-EZ and it was Grrrrr8 but heavy..

Jeremy, there are several engine discussions on this site that should provide you with food for thought.

On the banner above, select "forums", then "open forums" and do your search (engine CH650, engine CH601, engine zodiac, etc.).

My experience: I had settled on the WW Corvair, as there are lots of good stories about it (from the technical point of view) and it seems to have become a mature solution for a good price. When I made my mind, I sent a note to William Wyne, followed the next day by an addendum. That was Jan 20, 2016. Despite his claims of easy access by email and phone, I haven't received a reply. If this is the reaction I get when there is over US$10K on the table, what can I expect when I need a part, or just an answer to a question? So, Corvair is out (yes, there are other conversions, but I'm not going there).

So I searched and found a used Jab 3300, recent "vintage", for a decent price. Jabiru had teething problems over the years, but it is now a mature product.

That's what I'll have on my Zodie.

There are other very good alternatives out there, but I wanted recent and simple technology (no PSRU, preferably air cooled) and a price that would not break the bank.

Good luck

Hi Carlos, I live in Perth Western Australia and I had decided that a corvair might be the go. I chucked many emaills WW,s way but got very little in return. The amount of core engines in this country are very few and I wanted a ready to go one. I thought he was an arrogant bastard and do not know how he survives. He never gave a price or even said if they were available or not. I then went the Viking way, Jan I think is similar to WW but at least I got an  engine from him and now it is bolted in my 650 and am just doing the cowling. It seems to me that if you invent or make a auto conversion engine you think you are some kind of important person and customer service is for other people. Hope you have a good run with your Jab, and visit the rotec radial website as they make some good bits for Jabs also. Regards Barry. 

Hi Barry

Maybe we should have a beer at Oshkosh some time.  Or go fly together :)  I am the last person feeling important about myself.  

But you are right, I am not the best people person in the world.  I am lucky to have Jordan do that part now.  


Viking has an active forum to discuss any issues regarding the engine and my experience is that Jan replies within a day if emailed personally. Not sure what level of service you are after but if you feel the need to critise publicly then tell people you are from somewhere other than Australia.

Mr Sweeney

Arrogant is debatable, but bastard isn't: my parents just celebrated their 65th wedding anniversary and I am only 53 years old, so maybe stick to calling be arrogant.


I am not in the habit of calling people names because they live 12,000 miles from me and don't focus on the item I want to buy today. We have many builders and flyers in Australia  but almost every one of them took the time to learn about and build their own engine. This makes sense, because the geography dictates that they will be their own front line service department. That system works, and for the same reasons, I don't focus on exporting complete engines to builders. As I pointed out in the longer post in this thread, there is a good match for each set of circumstances, and a Viking is better for yours. Your comment that you find Jan and I similar, says that you really were focused on getting the engine, and the relationship with the supplier didn't count as a large factor. Typically the people we work best with have a different perspective.


I have no false modesty about what I know on my products, teaching builders, and aviation. I graduated from the worlds finest aviation university; In a field where the average life span of a company is 36 months, I am still here at 27 years: I have had many days of joy in aviation and known some of it's bitterest hours; I have a very large commitment to others that follow having a safer, smoother path. You are correct about this: I do think of myself as important, not in the ego sense, but in the sense that I have played an important role in the learning and progress of hundreds of builders, by working with them one at a time. However I will confess that not many of those productive relationships started with a guy who never met me getting on the net and calling me an arrogant bastard. -ww.





I have heard the same about the Corvair conversion guys. Some people send out cases or crankshafts and wait months or over a year to get the mods done and get them back. No phone calls or emails get returned. I plan on using an O-200 I already have or purchasing a used Jab or perhaps other conversion.

Mr Sa,

 Perhaps you missed this, But there is an announcement on my website that Sport Performance Aviation take care of the sales, distribution, and much of the tech support for our products. Your email was sent to my traditional email. We are a mom and pop business, and I spend a lot of time on the road at Corvair Colleges, SPA stores, ships, and answers questions about our stuff 9/5 m-f, I have been friends with the Weseman's for 15 years, the arrangement allows me to work hands on with builders in the field and meet family care commitments to my parents.

I have a very extensive website, every question in your note could be answered with detailed stories that are on my site. Please note that a guy shopping with $10K for a complete motor gets the same consideration as a guy looking to buy a conversion manual, they are both homebuilders, and as a general rule, no potential customer is more important than  a current builder.  Your hint that there are other Corvair sources, is poor advice. There have been a number of here today gone tomorrow LLC's that took the money of zenith builders and folded. 27 years after getting started, I am still here, no LLC, we have a lot of people flying, evidently it works for many Zenith builders. -ww.

Mr Hall,

Some of the stories you have heard of are the same people that Mr Sa is hinting at as alternatives. If it has the word "Corvair" attached to it doesn't always mean that it was done by me or anyone I would approve of. As a simple example, you mention crankshafts, that is an item we don't process, and some people seeking a cheap alternative don't use our recommended supplier. I gladly take responsibility for the time line we have but not for everything labeled 'Corvair'

95% of the builders we are working with are building their own engine. It is a learning process, and the people who get the most out of it are not in a rush. They are planners by nature, and the majority of them are willing to do their homework, send parts in for processing in advance, and take advantage of a Corvair College in their area to assembly and test run it for free. These are the builders who are best matched to the strengths we offer. People looking to buy and engine on short notice have never been the focus of my work. -ww.


New from Zenith:

Zenith Planes For Sale 

Classified listing for buying or selling your Zenith building or flying related stuff...

Custom Instrument Panels
for your Zenith

Custom instrument panels are now available directly from Zenith Aircraft Company exclusively for Zenith builders and owners. Pre-cut panel, Dynon and Garmin avionics, and more.

Zenith Homecoming Tee:

Zenair Floats

Flying On Your Own Wings:
A Complete Guide to Understanding Light Airplane Design, by Chris Heintz

Builder & Pilot Supplies:

Aircraft Insurance:


West Coast USA:

Pro Builder Assistance:


Transition training:

Lavion Aero

K&S Aviation Services

Aircraft Spruce & Specialty for all your building and pilot supplies!

How to videos from HomebuiltHELP.com

Developed specifically for Zenith builders (by a builder) these videos on DVD are a great help in building your own kit plane by providing practical hands-on construction information. Visit HomebuiltHelp.com for the latest DVD titles.

© 2024   Created by Zenith.Aero.   Powered by

Badges  |  Report an Issue  |  Terms of Service