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  #11  
Old 11-01-2014, 11:10 AM
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rvbuilder2002 rvbuilder2002 is offline
 
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Originally Posted by RV7ator View Post

A wife's happiness also has a proportional baggage component. The -14 desperately needs a baggage door to take advantage of the capacious baggage volume. It looks silly without one. It's a clumsy and awkward struggle up the wing with anything clunky and/or heavy, maybe passing it through the seat-roll bar gap in the bag area. Tip the seat forward and it's now in the way of stepping in. Try all this with a loaded, but melted ice, ice chest!

The tip-up slider on my -7 makes loading oh so easy. Stand on the ground and directly drop in The Big Bag. Maybe Van's can devise an open-able rear window. Something!
Actually, the RV-14 is the easiest to load baggage in of any of the 2 place side by side models. With the lower cockpit side rail, the opening between the rear seat support structure and the roll bar, is proportionally taller than all of the others. This makes it much easier to get most anything into the baggage area (including a cooler with water in it), and you don't have to lift it as high because of the lower cockpit side.
For this reason, and with the added weight, build complexity, and cost that would be induced by adding a baggage door... it is not likely to happen.
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Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #12  
Old 11-01-2014, 11:21 AM
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Originally Posted by kamikaze View Post
"negative comments in the past regarding the decision to choose the IO-390 as the focus engine for the RV-14"

Indeed ... one of the issues for me is not just the engine itself, but the lack of alternatives that will fit relatively easily in there. The XP-400 is the only one AFAIK.

Thing is these days there are plenty of engines like the IO-375, X-371 or X-409 that could also fit the bill ... if it weren't for the weight issue ...

Finally, the IO-390 is avgas only, an issue for some in north america, and an issue for everyone outside north america ... a strange choice from that point of view ... At least the XP-400 or whatever BPE will build for you can have mogas friendly low compression configurations ...

A FWF kit that will support the lighter engines (appropriate engine mount and cowl?) would certainly be a great seller I'd expect ...

This whole engine business is really driving me bonkers about choosing the RV-14!
Designing an aircraft for optimal performance and utility is a juggling act of compromises.
The engine choices for the RV-14 was narrowed to optimize the kit for the major majority of people.
Yes, that pretty much locks in the use of an angle valve derivative of the 4 cyl. Lyc. (because the parallel valve versions are too light) but that still leaves a lot of choices. The majority of the 200HP angle valve models can be used in place of the IO-390.
With creativity, it is possible to build up a just slightly lower compression version of the IO-360 engine to enable worry free use of mogas, and still have very good HP output.
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Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #13  
Old 11-05-2014, 10:55 AM
GigAir GigAir is offline
 
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Are there any cooling issues with the IO-390 in the RV-14a? What kind of CHT and oil temperatures have you witnessed? Thanks for all the great info and perspective, it helps tremendously.

Greg Novotny
Gig Harbor, WA
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  #14  
Old 11-05-2014, 11:10 AM
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Guilhermepilot Guilhermepilot is offline
 
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As a skinny guy I am glad to have bought a 7A with an IO360
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  #15  
Old 11-05-2014, 12:00 PM
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DanH DanH is offline
 
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This is probably a fair comparison, dead stock 390 in a clean RV-8. The photo was taken in the last hour of a non-stop from OSH this summer, so remember, light on fuel, and solo. Anyway, 11,500, WOT, slightly lean of peak, cowl door shut.

Thoughts...

The 390 is not a fuel hog when operated with an eye toward conservation.

There is a penalty to be paid for the larger RV-14 airframe. If you need the space, pay the bill. If you don't, well, don't.

I'll bet RV-14's cruise cooling drag could be cut by half. Then if we put the little wheel in the back....

I wouldn't want less engine in an RV14. As noted, it would burn the same for the same speed in cruise. However, it would climb slower...and the cool air is up there.

I'd probably like a Superior/BPE 400 even better.

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Last edited by DanH : 11-05-2014 at 12:04 PM.
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  #16  
Old 11-05-2014, 04:21 PM
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rv9av8tr rv9av8tr is offline
 
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I've found running 2300 instead of 2400 will dramaticly drop fuel flow with little speed penalty. Should be able to get 24-25 mpg instead of the 22.
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  #17  
Old 11-05-2014, 04:39 PM
joatmon joatmon is offline
 
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I'm wondering if the lighter weight issues with a higher performance IO360 that matches the horsepower of the IO390 could be helped by use of inverted oil and smoke systems. Not sure how much weight these add but could it keep the CG within limits?
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  #18  
Old 11-05-2014, 05:29 PM
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Quote:
Originally Posted by joatmon View Post
I'm wondering if the lighter weight issues with a higher performance IO360 that matches the horsepower of the IO390 could be helped by use of inverted oil and smoke systems. Not sure how much weight these add but could it keep the CG within limits?
You would need to make up for a weight difference of 35-40 pounds at the arm position of the engine C.G (~ 20 inches fwd of the firewall).
Any optional equipment added aft of that point would obviously have to be even higher in weight to get enough of a moment.

Some have suggested that enough compensation could possibly be made by installing air conditioning since the compressor is mounted out on the front of the engine. I haven't done any math, but I don't see how it could work. The compressor is no where near heavy enough to compensate for the lighter engine, and there are other components of the system would likely be reversing any gain from the compressor (in aircraft the condenser is typically mounted aft of the C.G.). Not to mention the extra money spent for the A.C. system, that would offset any savings gained by using a different engine.
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Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #19  
Old 11-05-2014, 05:38 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by GigAir View Post
Are there any cooling issues with the IO-390 in the RV-14a? What kind of CHT and oil temperatures have you witnessed? Thanks for all the great info and perspective, it helps tremendously.

Greg Novotny
Gig Harbor, WA
The trip I just made with the airplane had me flying in OAT's of 95 F. while in the Phoenix area. I can't give you specific #'s because in those conditions, with the flight profile that I flew, the temps were more than acceptable so I didn't take specific note.

The prototype currently has the same oil cooler as is used on the RV-10, remotely mounted and fed air with a 4" SCAT hose.

We have done gross weight climb tests at Vy, all the way to 10K ft in the same temp conditions and recorded acceptable CHT and oil temps.
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Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #20  
Old 11-05-2014, 09:01 PM
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erikpmort erikpmort is offline
 
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What does acceptable mean ???
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