Done two of them, first on the -10 and the second on a friends -7. Both where installed in James cowls, the -10 was a near "drop in fit", the -7 (200hp, forward intake) was a perfect fit.
I'm planning a 3rd on my -8.
Did it on my -10. It goes together well. Modified my vertical to a horizontal intake with an elbow from Rod and have the intake forward right behind the prop. A bit of fiberglass work on the cowl but it came out fine. Rod's video is very helpful. Not flying yet so no info there.
...... Is it providing any measurable benefits? ...... but added work to the build.......
Mike, is that between Ram and Alternate Air? Also is it harder to install the RB mod on standard cowls? (RV10 specifically)
Mike, is that between Ram and Alternate Air? Also is it harder to install the RB mod on standard cowls? (RV10 specifically)
I get at least an 1" or more MP over my friend's 8 with stock Vans intake.
That's the whole idea of ram air induction, you can switch it to unfiltered ram air at altitude. You might get more MP taking the filter out of the Van's snorkel but you can't do it in the air. The Mooney 201 had the same type of system.Typical quote, but again, a comparison of filtered (stock Vans) to unfiltered (Bower with butterfly open). Take the filter out of a stock snorkel and compare, or compare filtered performance for both.
is there a smooth version of the RV-10 cowl
Steve and/or Dan,
So if I dispense with the idea of ram air (Bowers or otherwise), is there a smooth version of the RV-10 cowl from Vans, or is my only option the Sam James Cowl? Also, am I correct in thinking that the main (perhaps only) difference between the two would be the shape of the inlets??
Steve and/or Dan,
So if I dispense with the idea of ram air (Bowers or otherwise), is there a smooth version of the RV-10 cowl from Vans, or is my only option the Sam James Cowl? Also, am I correct in thinking that the main (perhaps only) difference between the two would be the shape of the inlets??
I dug up one of my Dynon data logs.
altimeter setting 30.19
DA 10591 indicated altitude was 9000 using the standard snorkel and filter.
PA 8765
OAT 13c
TAS 169kt
FF 8.6 gph
MP 21.5 In Hg
RPM 2605
I looked up the standard altitude and found that at 9000 ft the std pressure is 21.4 inches Hg.
.The showplanes cowl looks nice. I wonder if there have been similar issues with inadequate cooling that Sam ran into..?
I dug up one of my Dynon data logs.
altimeter setting 30.19
DA 10591 indicated altitude was 9000 using the standard snorkel and filter.
PA 8765
OAT 13c
TAS 169kt
FF 8.6 gph
MP 21.5 In Hg
RPM 2605
I looked up the standard altitude and found that at 9000 ft the std pressure is 21.4 inches Hg.
The Dynon log does not record indicated airspeed. A question for the Engineering gurus, do the pressure to airspeed charts relate to indicated or true airspeed?
The chart that I have has 150kt at .5358 psi and 180kt at .7786 psi
1 psi = 2.0362 in Hg so .5358 psi should equal 1.09 In Hg and .7786 psi should = 1.58 In Hg. Yes / No ?????
I am quite certain that filtered vs unfiltered air in the Bower system will yield 1" of difference due to the fact that the pressure in the lower cowl is lower than the upper cowl (my pressure differential is about 10 inches of water) as well as the airflow restrictions due to the reed valves and filter.
Has anyone removed the filter on a snorkel and done a comparison flight?
I set up my flow bench to flow 250 cfm with nothing on the vacuum side, then placed several items on it to see how they flowed.
33-2060 std snorkel filter with a square plenum = 243cfm
RU-2520 Bower filter with plate on open end. not installed in can. = 250cfm
In can with valve open = 249 cfm
in can with valve closed = 225 cfm.
The Bower reed set up is about 5.76 sq inches area with reed open, but they cover a large portion of the filter.
a 2 15/16 hole has an area of 6.77 sq inches. This is the ID of the Bower valve.
I like the Bower install. the scoop is nice, the can fits nice, but I think that a better set up would be full time filter with an efficient alternate air.
I performed a condition inspection last week on an RV-10 with the Rod Bower setup that has an air filter hanging off of the engine mount and a long scat tube down to the intake. I was shocked at the loss of performance on takeoff. It is noticiably different by a huge amount. I performed another takeoff and opened the bypass at 10 feet in the air and the engine surged, and I mean REALLY surged. There is at least 2-3" of MP loss from what I can tell. I have another RV-10 now that I am doing a condition inspection and it has the filter removed, so that it is ingesting unfiltered WARM cowl air for takeoff.
I do not like this set up. My opinion only.
Vic