Unique Modifications

Thought I might start a thread here that would be useful for those at the concept stage of their build:

Vans has put together great kits, and just completing an amateur build in a 'standard' manner is certainly one way to go. We also get the freedom to keep the 'E' in experimental. I didn't fully appreciate that until I was well into my first build.

Chime in with your unique larger modifications, maybe new builders will get inspiration for the 'do-able,' or even a better appreciation for Van's Plans.

Things like unique Engines, Air Conditioning, FADEC, Oil System modifications, Cowl changes, unique cockpit mods, etc. If you made a mod that didn't work out, then that's good to know as well. Critical speculative opinions on other people's modifications are not really the ask here.

Maybe provide a few 'Pros and Cons' based on what you learned?

There is probably someone out there that wants to ask you how you did what you did.

I'll start

RV-10
Barrett IO-540 with Cold Air Induction, 9:1, EFII
Dual Alternator, Dual Lithium Battery, Split bus with crosstie architecture
Showplanes Cowl and Induction
3 piece Split lower cowl
Reiff Preheat
Custom Aircraft Exhaust
MTV-9 Prop and 15" spinner
Linear actuator heat/vent valves and oil cooler
Manually controlled heater bypass system
Garmin G3x Touch Suite
Aerosport rudder trim converted to linear actuator control
ER Fuel tanks using a solid state timer relay for control
LED wing root taxi lights
TCW inspired aft avionics tray
Upper forward fuselage access panels
SS Entry/Exit handles
McMaster Door Seals
Plane Around third latch
Aerosport interior
Seat heaters
PH Aviation flap actuator
Matco Brakes and wheels
Desser Retreads
Airward tunnel access panel
All Deutsch connectors
Mostly primed
Aluminum windscreen fairing
SteinAir avionics
Leather glare shield cover
Noctua 120mm avionics fans
Two lever quadrant
Cee Bailey windows

...and hopefully in May, Evoke Aviation Paint!

Mod

Biggest "Mod" has been the cowl. I modified it to connect to the plenum. Basically the inlet portion of the top cowl was bonded to the bottom cowl so the inlets are sealed units. Ohoto.
The smaller mod was installing gates in the louvers to adjust exit air.

A few extra projects on an RV-7

Air Conditioning:

Airflow Systems automotive components adapted for RV installation. A capable cooling option for the hottest days on the ground or trolling at low altitude. Reliable, easy to maintain, and so far leak free.

Pros -
#1 AC...duh,
#2 also nice cabin air circulation even without the compressor running

Cons -
#1 weight, probably >40 lbs when all is said and done.
#2 CG shift aft.
#3 figuring out how you will run the high and low pressure freon lines from behind baggage to front of engine. This can be done externally under covers on the belly. I chose to run them internally and that took some work.
#4 compressor will partially block port side cowl inlet.

Oil Accumulator:

Moroso 1.5 Qt heavy duty. Probably worthwhile, used on every start-up.

Pros -
#1 Pre-oiling. This is a debatable benefit. Warm climate airplanes that run regularly may not see any benefit here. I picture this as more beneficial for my airplane that cold soaks for a month at a time in the low teens - 0F. Aluminum bearing webs in my engine will squeeze most if not perhaps all of my oil film off my crank journals by differential thermal contraction. It's a comfort to replace that film after pre-heating my engine before start.
#2 Extra 1.5 Qt of oil that can be added from the cockpit whenever it is needed.
#3 zero-G, (or negative G if you don't have an inverted oil system) oil pressure drop buffer.

Cons -
#1 Automotive accumulator designers don't really consider the possibility of hydraulic lock bursting (at least not at Moroso). Some thought needs to be given to monitoring its charge and dealing with a piston that may bottom out. You cannot reliably charge your accumulator by referencing engine oil pressure. Most oil pressure gauges measure engine oil gallery pressure downstream of the regulator. If oil is cold the pressure upstream of the regulator (where we typically Tee in the accumulator) can be a lot higher and an accidental overcharge is very possible. Next a reliable safety pressure release needs to be added, and its output routed somewhere safe.
#2 Weight. Probably 8-11 lbs depending on how you mount it and whether you go with heavy duty construction. Could be a 'Pro' if you install AC and need a CG shift forward.

Round engine

I ran way out into the weeds with a R3600 Rotec 9 cylinder and an 84 inch Whorl Wind prop. What has been said numerous times, changes from the plans really add considerably more time to the project couldn’t be more true. Just about EVERYTHING firewall forward has to be custom fabricate. Notice that blue step stool that was one of several prototype engine mounts

Pic way too cool to be sideways

wirejock said:

Biggest "Mod" has been the cowl. I modified it to connect to the plenum. Basically the inlet portion of the top cowl was bonded to the bottom cowl so the inlets are sealed units. Ohoto.
The smaller mod was installing gates in the louvers to adjust exit air.
View attachment 22847

Click to expand...

Pretty cool. The phone that is! Does it work?
How did you get such a nice even cut on the upper cowl?

wirejock said:

Biggest "Mod" has been the cowl. I modified it to connect to the plenum. Basically the inlet portion of the top cowl was bonded to the bottom cowl so the inlets are sealed units. Ohoto.
The smaller mod was installing gates in the louvers to adjust exit air.

Click to expand...

Looks amazing!