From Van's Facebook page:
SELECTING AN ENGINE FOR THE RV-14/14A
The RV-14/14A was designed around (follow closely now) the Lycoming IO-390-A3B6. This is a:
? four-cylinder
? horizontally-opposed (the ?O? in ?IO?)
? horizontally-inducted
? fuel-injected (the ?I? in ?IO?)
? angle-valve
? normally-aspirated
engine rated at 210 hp
This engine is comparatively new and is found almost exclusively in the Experimental market. It hasn?t had the need or time to mutate into the bewildering variety of versions that older Lycoming designs have achieved. The version we sell ? the IO-390A3B6 ? is configured with a standard Lycoming sump, Bendix-style injection, Slick magnetos and a forward mounted prop governor. Because very few IO-390s appear on the used market, we can assume that any IO-390 in an RV-14/14A will have been purchased from Van?s and will fit the RV-14 without trouble.
ENTER THE IO-360
It?s been apparent from the beginning that the IO-360 Lycoming engine is so similar in configuration, weight and power to the IO-390 that it might also be suitable. We decided to try this when we built our RV-14 prototype and have found that this engine is indeed a good match to the RV-14 airframe.
Since the IO-360 is available on the used market for prices far less than a new IO-390, it is an attractive option for builders who are on a more limited budget. It also opens up a new can of worms.
First, we have to define some terms. There are THREE completely different kinds of IO-360:
? the common Lycoming parallel valve four cylinder engine, usually rated at 180 hp. They can be horizontally or vertically inducted.
? the completely different Lycoming angle-valve four-cylinder engine rated at 200 hp. These are always (dare we say that?) horizontally inducted.
? the Continental IO-360 six-cylinder engine rated at 210 hp with the induction system mounted on top of the engine.
For the RV-14 the only suitable IO-360 is the Lycoming angle-valve 200 hp version.
This engine has been production for decades and when we wanted to test a 200 hp version of the RV-14, we installed an IO-360-A1D6 in our RV-14 taildragger prototype ? simply because we already had one. It is working well ? physically it fits fine, produces plenty of power and works well with the weight/balance envelope.
The IO-360 exists in a bewildering variety of versions. Only some of them will work.
One of the most important red flags is the location of the propeller governor. The IO-360-A1D6, like the IO-390, has the governor mounted on the front left side of the crankcase. Many, probably the majority, of IO-360s have governors mounted on the rear accessory case, where it physically interferes with the steel engine mount/nose gear of the RV-14A and causes many ducting/wiring/routing problems for the RV-14. From what we can tell, it is not feasible to convert a rear governor engine to the forward governor configuration. We recommend that RV-14 builders avoid IO-360s with rear-mounted governors.
Some IO-360s have been removed from aerobatic airplanes and are equipped with different sumps and induction systems. We have not investigated, let alone prototyped, any such engine and recommend anybody contemplating putting one in an RV-14/14A do some serious homework before they buy.
There are two or three companies building Lycoming ?clones? ? engines similar to, but probably not identical to, the Lycoming. These engines can come in almost any configuration the buyer wishes, but again, Van?s has never seen most of these engines, and has certainly never investigated which, if any, of the many available versions might work in the RV-14/14A.
To summarize, we recommend that RV-14/14A builders choose Lycoming-type engines that are
? four-cylinder
? horizontally-opposed
? horizontally-inducted
? angle-valve
? normally-aspirated
? forward-governor
? standard Lycoming sump
and rated between 200-210 horsepower.
The only engine that Van?s sells that meets all those criteria is the IO-390-A3B6. The 200 hp IO-360-A1B6 engine we sell for the RV-7/8 is a rear governor engine, and unsuitable for the RV-14/14A.
Builders contemplating buying an engine from some source other than Van?s will be responsible for making sure their engine is suitable. Calling Van?s for information (?I?ve found an IO-360-X4B12?# out of an Egyptian Air Force Malmo-Boero. Will it work??) will not help. Contact Lycoming or an expert engine shop for details of a given model, and insist on seeing photos or examining the engine to determine whether it will work.