Induction air setup with Airflow Performance

[cduster]

Hello gentlemen,
I am thinking about doing away with the ram air setup on my HR2 and going with something that includes a full time filter. This would be with the forward facing Airflow Performance induction. Has this combination been done much before, and if so, whats it look like on the exterior of the lower cowl?
Thanks,
Craig

[titanhank]

Originally Posted by cduster

Hello gentlemen,
I am thinking about doing away with the ram air setup on my HR2 and going with something that includes a full time filter. This would be with the forward facing Airflow Performance induction. Has this combination been done much before, and if so, whats it look like on the exterior of the lower cowl?
Thanks,
Craig

I have the rear facing injection system on my rocket. I talked to john harmon a few months ago and he mentioned he had a kit to turn it around and connect to the existing air intake. I have not pursued it yet, but i would like to get rid of the unfiltered ram air.

[I-TERA]

Hallo Craig,
I modified my lower cowl to accept an inlet and a reversed conical filter mated with a canister providing an alternate air intake and a flange to be connected with the Airflow Performance metering unit via a short flexible silicon duct.
The inlet and filter are removable from outside to inspect and clean.
A strong lip avoid any movement of the filter toward the engine also if pushed by foreign object.
The sump is a Barrett cold air.
Here some pics and drawing:
https://www.dropbox.com/sh/1o57quevc...-Lqi4bV6a?dl=0
Claudio

[cduster]

Thanks Claudio, that looks like a very clean and compact design. Am I safe in assuming that you see manifold pressures very close to barometric pressure?

[I-TERA]

Yes, if WOT at 200kn , the manifold is a little higher than the static ( difficult to appreciate ). At low speed and full power ( take off ) the pressure is a bit greater than static due to the proximity of the inlet to the propeller.

[Aden Rich]

While the original HR2 inlet was never really "RAM" air because of the way the alternate air source selector was made. If you had the selector on outside air, the gate was parallel to the sidewalls and allowed any excess air that the engine was not pulling in, to bleed out the side that was attached to the alternate air ducting. Any excess was just blowing into the side of the cowling.

F-1 Rockets had a scoop with an air filter and you can buy the inlet that needs to be mated to your cowling with their filter.

You can also use something in between and is a nice product that Rod Bowers makes that is true "RAM" air and has sprung flaps that in the event of blockage, the suction of the engine will pull them open. The RAM air pushes them closed and all the forward motion of the airplane plus the prop pulses are compressed into this induction. I know folks that have this and get 1.5 inches increase over stock at cruise.
I like the looks of the Rocket myself so you could remake the Y inlet to have two gates with two control cables that would have to be used when using alternate air. The 2nd gate would fully close off the alternate air throat and then all the "RAM" air would go into the engine. http://www.ramairforhomebuilts.com/products.html

[DanH]

https://vansairforce.net/community/s...t=44856&page=2

[titanhank]

Originally Posted by titanhank

I have the rear facing injection system on my rocket. I talked to john harmon a few months ago and he mentioned he had a kit to turn it around and connect to the existing air intake. I have not pursued it yet, but i would like to get rid of the unfiltered ram air.

When ram air cable is pulled, i get .5” hg rise. Not worth the trouble in my opinion.