UnPossible

UnPossible

Well Known Member
Hey - I'm finishing my RV-7A empennage and just ordered the QB wings and Fuselage and now my thoughts are turning to engine selection.

So far I am a bit over whelmed with all the different Lycoming engines that are out there. Below are three questions that I'd love some insight on.

1) Is there any sort of "cheat sheet" that would explain what all the different numbers / letters mean?

2) Is there any sort of a concise write up as to the various advantages / disadvantages?

3) What all do I have to know before I order the finish kit?

Thanks,
Jason
 
Last edited:
One thing that makes life easier is to get an engine with the prop governor mount on the front left of the case. If you have this configuration and a glass panel to eliminate the vacuum pump it really opens up the firewall area for ease of maintenance. Don
 
Jason, its good to know what all the variants are, but if you want to buy a new engine for your project it is quite simple in fact.

Make these decisions:

FP or CS prop?
How many horsepower?
New roller lifters or old tappets? (Not sure that is quite the description)
Carb or injection?
Compression ratio?

You will want Dynafocal, though I forget which is standard I or II but the one VANS offers in the catalogue.

Once you have done that you can look up that engine in the VANS catalogue. If you want other than a Lyco, or VANS as a supplier, go to your favourite engine builder and tell them what you want with the answers to the above questions. I think if you approach it that way you will be far less confused.

If it is a -4 there are a couple of other issues, but you are probably not that privileged! If so let me know.

If it is injected make sure you buy the correct lower engine cowl.

If you want a second hand engine....you had better learn the numbers.

You might also want to think about what mags you want on the engine. Conventionally yo uwill get Bendix I think (or is it Slick?), but you may want to think about electronic ignition. (I have P-mags and they work great.)

Hope that helps.
Good luck.
 
LYCOMING

The Lycoming publication Directory of Certificated Engines is what you need. Available in print or online from the Lycoming website. Also tells what production airplanes used a particular model engine.
 
Hey, knock yourself out going through those spec sheets, but they leave a lot to be desired. For example, I never found any indication of which engines are horizontal induction and which are vertical - seems like critical info to me. The listed designation also can depend on things like what fuel injector or ignition system is installed - that can be ignored if you are having someone like Aerosport power build your engine - they will put what ever system you want on it. Similarly, he can install cylinders with a higher compression ratio than spec. In the end, your engine placard may say "IO-360B1B" (like mine) but that doesnt mean it conforms to the spec sheet. Funny eh? Or not.

If you want to make things as easy as possible, go with an engine that Vans sells and has a set finishing kit for. Very straight forward. Many dont do this (I didnt), and thats ok, but you may have to ad lib a little, roll your own control cable bracket, figure out for yourself the best spot for the firewall penetration, get a longer control cable, etc. All very doable, just takes a little care and patience.

My recommendation is to get on the phone and talk to a few of the engine manufacturers as well as Vans to start getting educated. I love Aerosport Power, but there are others that many recommend as well. Ask them for recommendations on engines and features, and then find out their reasoning. When you think you know about what you want, run it by Vans to get an idea of what issues there may be with the finishing kit components. Run it by the folks on this list. It takes time to do the research, but its well worthwhile.

regards

erich
 
Steve Sampson said:
New roller lifters or old tappets? (Not sure that is quite the description)
Click to expand...

Just a side note on this issue. The question or roller tappets or flat tappets can now be posed as this:

If you want a new engine, will it be Lycoming or ECI? With Superior leaving the market, Lycoming is the only company making roller tappet engines and all of their new engines are roller tappet. ECI does not have a roller tappet offering. If you decide to use a mid-time engine or an overhauled engine, you will also only be able to use flat tappets. There is no reliable field modification to convert a flat tappet engine to roller lifters that I am aware of.

Good luck!
 
point of clarification, in case you didnt know:

Both complete engines and engine parts come from Lycoming, ECI, and until recently at least Superior. But, if you have one of the engine shops build up your experimental engine for you, using parts from one of these suppliers, the shop name goes on the engine as the manufacturer. Thus, I have an "Aerosport Power IO-360B1B" engine - even though all the primary engine components (cylinders etc) are ECI.

Whats really weird: Guess what name is on the cover of the manual that came with my engine (supplied by Aerosport Power)? LYCOMING. Seems like Lycoming wouldnt want their manuals distributed with products that they had nothing to do with, but what do I know?

erich
 
You must log in or register to reply here.