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Best engine for -14

Wingit

Active Member
I am new to the forum and I am sure this has been previously discussed but not sure how to mine previously discussed subjects. But I am looking for input on engine choice. I am sure that I want the Lyc. 390.
Is the Thunderbolt worth the extra AMU?s $ and wait time
Which ignition is the best choice
Is the kit exhaust the way to go

Thanks

Dave
 
I've really enjoyed the Thunderbolt IO-390 with dual PMAG ignitions. Between the EarthX and the PMAGs it starts half prop every time. Engine is smooth and powerful. Would do the Thunderbolt again, definitely.
 
Dave, being new to the forum, here's an important clue...When asking for "best", most of the advice you'll get is based on pride of ownership, not critical analysis.
 
Search...

A good way to mine info from the forum is to use Google...
Use this format to force Google to only show results from VAF: RV14 engine site:www.vansairforce.com

Not perfect, but it?s where I often start
 
If you are going to stick with what is the easiest installation, aircraft engine, as far as I know the only option at this point is Lycoming IO390. I am not aware of anyone putting a auto engine in a 14 and the 400 has been pulled due to issues.
 
If you are going to stick with what is the easiest installation, aircraft engine, as far as I know the only option at this point is Lycoming IO390. I am not aware of anyone putting a auto engine in a 14 and the 400 has been pulled due to issues.

The prototype RV-14 (tail dragger) has an IO-360A1D6, so there are options other than the IO390 as long as they are an angle valve variant and have a fwd mounted prop governor.
 
If you're more interested in the easiest build pathway go IO-390. I have the Thunderbolt version, but if I were building again I'd think a litter harder about going with stock IO-390. I really am happy with the Thunderbolt, but having flown the factory prototype for training with Mike Seager, I'm not sure I can tell a difference. If budget is important, I think the stock engine is great. I did go with one PMAG/one magneto - many options there as well.

Going with the IO-390, in general, smooths the road for a builder: everything in the finishing and firewall forward kits is set up to make this easy. The more "standard" you go in the -14 build, the easier things get. I went with Airflow FM-150 fuel injection which required some minor mods, but the standard system is very good and proven and is easier to install with the Vans supplied kits. I did like working with Don at Airflow to tune my system - Airflow's technology and tech/customer support are superb.

I know builders who've done different fuel systems (fuel return lines etc), fully electronic ignition and fuel injection, and many other changes to the standard setup: these choices are great but no doubt add lots of effort to the build process. Bottom line: how much time do you want to spend adapting your choices versus the smooth and proven pathway of Van's excellent standard kit choices?

Ignition is an interesting question. I recommend you read up on the magneto timing discussions around IO-390, maybe even talk to Lycoming. Angle valve engines have different timing requirements from more common parallel valve engines, which makes the method and programming options of electronic ignition systems an important topic. I went with one PMAG, one magneto mostly because I like the idea of two independent sources of ignition. However with the IO-390 you need to use the less aggressive profile and retard timing a bit, and it's been pointed out to me that in cruise I'm effectively using only one ignition source due the variable timing curve of the PMAG vs standard mag. I may eventually replace the old school magneto with a second PMAG - I suspect this will result in some improved efficiency. If I were building again, I'd go fully electronic with PMAG or another vendor - that would require some added work because (at least at the time I ordered my engine) Lycoming will do no ignition, standard mags, or 1PMAG/1standard mag. I'd have to mount the ignition myself if going with another option: not necessarily difficult but no doubt adding some time/work to the build.

I am happy with stock exhaust: again Van's makes the standard option very easy to go with - Vetterman has a great reputation but from what I've seen, requires some mods to standard setup. IIRC, their system exits the cowling forward of the tunnel that's in place for stock exhaust but don't hold me to that...
 
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Another YIO-390 Thunderbolt here, with one Slick magneto and one EMAG. So far, so good. Pulled the plugs last week and they seemed a bit black (running rich) so I may try lean of peak now that the -390 is well broken in.

Good power and very smooth. Here are a couple screen shots of typical performance @ 9500 ft and 17,500 ft in my RV-14A coupled with the YIO-390. Best performance seems to be around 9500 ft (170 ktas @ 11 gph):

3575-RV-14-A-ALT-AMPS.jpg


N992-RB-175.jpg
 
When I built my -9, I went with an "approved" engine (O-290d2). While a great match for the -9, the engine installation took a long time because the standard parts did not fit and I spent a lot of time fabricating things.

If you want to go fly, build it exactly to the plans with the recommended engine and accessories.
 
Dave,
Welcome. I built my 14-A with a new Lycoming IO390 sold by Van's. It is not the Thunderbolt so I cannot compare. I have flown a 540 and 360 for 20 years prior and will tell you the IO-390 is smoother than the prior motors. Call Lycoming if you want to discuss the differences, great people.

I ordered the IO390 with dual slick mags, starts immediately with the Earth-x 900 and exact same mag drop when tested. 2400 TBO! I will change one of the mags at the 500 HR inspection for a new Sure fly ignition if those prove to be reliable.

Combine the Hartzell c/s prop when you buy the Lycoming and get a nice discount from Van's, especially at Oshkosh. It is pretty hard to beat the value of Van's for the Lycoming/Hartzell combination when considering the TBO and quality. The Thunderbolt is icing on the cake!
 
I went with the standard 390 and a 74 inch Hartzell (72 recommended). I choose one slick, one PMag.

Is Thunderbolt worth it? I obviously did not think so but if you have better finances than me, want a specific colour or the best chance of having a super smooth engine then of course, go for it. :D

I'm interested in your reasoning to go with the 74" versus the 72" prop. I am also looking at it. What do you think the 74" gives you in increased performance?
 
Regarding prop ground clearance (and other things), don't design for nominal. Design for those annoying off-nominal times.

Dave
 
My experience...

I went to Oshkosh in 2017 fully expecting to order the IO-390 Thunderbolt engine for my -14; however after hours of looking and talking and comparing, i could not find the value. So I went stock IO-390, also stock injectors which GAMI test within 0.1 to 0.2 GPH. Engine runs smoothly lean of peak until so lean they all quit. Stock exhaust. One Slick magneto, one pmag. After prop balancing it is at 0.02 IPS vibration. Very smooth. I?d do it the same way if I were to do it again. But Those with T-bolts seem to love them, too. Don?t think you can go wrong either way.
 
I went with the T-Bolt version as I thought it is a one time expense and might be worth it, it may give some bragging rights but not much more.

I might have been wrong with but I don't have any experience with the stock IO-390 to compare with.

However this engine compared to my old IO360, is much smoother and NO oil leak what so ever. I attempted to do a dynamic prop balance after phase one. We found the worse case RPM (2300) was at .017 and at 2500 it was at .013. Nothing was added as the A&P who did the prop balance thought adding anything would make it worse.

But I need to emphasize that vibration is caused by a number of factor and I am not crediting the T-bolt alone for the smooth engine.

The paint job however looks very pretty, I wish I could fly it with the cowl off :)
 
Do I understand correctly that the Thunderbolt spends more time on the test stand and therefore can reduce some of the worry of a proper engine break-in procedure during initial flight testing?

If so how much more time?
 
Do I understand correctly that the Thunderbolt spends more time on the test stand and therefore can reduce some of the worry of a proper engine break-in procedure during initial flight testing?

If so how much more time?

I don't believe so, both my T-Bolt and standard IO-360 came with 1.5 hour of test run with the result and stats listed.
 
That brings up an issue that has been nagging at me since I started my build. My home field is at 6200 feet, with density altitudes much higher than that in the summer, sometimes up to nine or ten thousand feet. There is no way I'm going to be able to generate enough power for a proper break-in and it just grates on me that after spending a boatload of money on either the standard or thunderbolt engine that I'm going to have to live with higher oil consumption and maybe even glazed cylinders simply because of where I live. Does anyone know if you can pay Lycoming to do a more comprehensive break-in on their test stand for people like me? I'd have to dig a hole to get down to the field elevations that most people fly.
 
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