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  #21  
Old 03-14-2017, 06:10 PM
Jim Slesser Jim Slesser is offline
 
Join Date: Oct 2013
Location: Burr ridge Illinois
Posts: 18
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Vetterman advertises that RV builders never need to modify their planes to install its exhaust systems. This thread seems to be indicating that is not the case with the 14 14a !! What do those with installation experience have to say ?
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  #22  
Old 03-14-2017, 07:07 PM
Av8rRob's Avatar
Av8rRob Av8rRob is offline
 
Join Date: May 2005
Posts: 161
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FWIW, I spoke to Clint today and as of now they are only offering a twin pipe exhaust that does not go thru the tunnel. He said builders will have to cut the bottom of the cowl for the pipes to go thru. Apparently this cleans up all the routing around the nose gear assembly. Personally I think that would look strange having an empty tunnel and pipes sticking my out of the cowl bottom. I guess you could close up the tunnel but what would that do for engine cooling airflow etc?
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Rv-14 Fuse
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  #23  
Old 03-15-2017, 09:37 PM
KeithB KeithB is offline
 
Join Date: Mar 2014
Location: Granbury, TX
Posts: 92
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I built my RV-14A with a Superior XP-400. As discussed, Van's exhaust for the IO-390 will not fit on the XP-400 due to Superior's cold air sump. I contacted Vetterman who provided their 2-to-1 by 2 exhaust (each side has 2 pipes joining to one 2" pipe - separate units for each side). I understand this "trombone" design has been used on RV-7s - it adds a loop in one exhaust pipe on each side before they join together to spread out the exhaust pulses. With this design, the 2" pipes are too large to fit in the tunnel, so the pipes must exit the cowl similar to other Van's models - in the case of the RV-14, this is forward and below the cross hinge on the nose gear.

Here is the right side:


... the left side:


Here is the view from below:


View from the side:


The parabolic cutouts are the only cowl mod I had to make:


These are two views with the cowl installed:



The plane has only flown 13 hours so far, but the exhaust is working great. I was delighted to require such minor cowl mods. I was concerned about clearance between the pipes, the nose gear and the cowl - there is about 5/16" - with engine shake at start up but I've looked at the video of my first start (the most shake I ever expect to have, but that's another story) and while the engine may behave like a wet dog on occasion, the pipes barely move.

Others have expressed dissatisfaction with having built a tunnel that isn't used. I initially felt that way, but now think of it as a cooling tunnel. During my first flight at 25 squared (75% power), the CHTs maxed out at 334 - on a day in the 70s. I now think I will not have any problems in the heat of summer and cowl louvers will be unnecessary.

I did experience some "drumming" on the floor boards, especially at high power settings like climb, but some carpet has helped quite a bit. Observers on the ground have commented the engine is a bit noisier than other RV's. The power is AWESOME!
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RV-14A Builder - kit #136
N314KC - First flight Mar 8, 2017, Phase I compl Apr 3, 2017
RV-6A sold
Sport Pilot (weight-shift control) - Airborne XT912
Dues paid 12/2016
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  #24  
Old 03-18-2017, 11:19 AM
NorrisAir NorrisAir is offline
 
Join Date: Mar 2014
Location: Veradale, WA
Posts: 18
Default Cowl flap in tunnel

I have the same setup as Keith Brown (XP400 with Vetterman exhaust), so I also have the empty tunnel. I had previously purchased a cowl flap from Anti Splat Aero so decided to install it in the tunnel. I had read that the 14 had plenty of cooling so thought that I might be able to reduce the cooling drag by installing the cowl flap in the tunnel. Haven't flown yet so no results data at this time. The cowl flap is electrically controllable and I added a position indicator so I can try different settings in flight and immediately see the impact on cooling and speed. If it doesn't work as expected then I'll just remove it.
I'll post results when she flies (should be soon).
Norris Brown (Interesting that Keith Brown and I went the same route though we have never met)
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RV14A - N14NP
XP400, Dual PMags, G3X System, ThermX Deice
First flight April 11,2017
Flying P210
2017 dues paid
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