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Jerry,
the last time you posted a drawing of your proposed intake
you had the ram air coming in right beside the airfilter.
Just make a box around all of the filter. Feed the ram air
into this box and have the unfiltered air intake beside the filter. Have either
of both intakes selected by a sliding plate. This way you have a chance to get
unfiltered ram air ( in case of filter icing) or filtered ram air. You mentioned
some times you only need 200 hp, but the way you seem to work your set-up, you
will probably see some 250+hp, so why not sacrifice a couple of horses for
the filtered air.
I am flying some 5000+ hours in front of filtered air only
- with the choice of heated air or unheated, but always filtered.
Robinson goes the same approach as you - choose an engine
with "too much" power and downrate it on the paper (Robinson Helicopter power
limits are only limited by max manifold values published in the POH, but all
available power is there when you need in an emergency and the
airframe/transmission can take it as well for some time)
In your case you are at least 50 horses on the wild side
of your needs, why not sacrifice a few for some clean air, no matter
where!
You are in the lucky position to be able to produce a
s$%&load more power than you need at the basically same engine
weight.
In case you want to go for all filtered only you should
have even more space for a bigger filter, but you might consider some way to
supply heated air, just in case...
Thomas J.
----- Original Message -----
Sent: Sunday, April 17, 2005 3:55
PM
Subject: [FlyRotary] Re: Apex Seal Groove
Wear and Air Filters was Re: [FlyRotary]...
On Sunday, April 17, 2005, at 03:41 PM, WRJJRS@aol.com wrote:
In a message dated 4/17/2005 9:27:23 AM Pacific Standard Time,
jerryhey@earthlink.net
writes:
Hi Leon. I am in complete
agreement about the need for air filtration.
On one hand we
have the need for filtered air and on the other we
want the performance
boost from ram air. If we supply ram air to a
plenum and filter it
before it enters the engine, is there a
significant performance
hit? If so could the ram effect be regained by
using a larger
filter, bigger scoop, and so on. I am building my
intake right now
and it will have filtered air with the option of
switching to ram air at
altitude. Do you think this is a good idea?
Certainly
some dust exists even at 10,000 ft.
Jerry
Jerry,
I'll be interested in Leon's take
as well, but I wanted to kick in here. Yes you can ram air a filtered
plenum. If you look at any of the newer motorcycles 600cc + you will find
that all the sports and performance bikes use ram air, and the largest
plemum box they can fit in the frame practically. There is a
noticeable power increase that I tested on the track. Run the biggest filter
you can fit in for the lowest pressure drop. I like the K&N oiled filter
element.
Bill Jepson
Thanks Bill, looks like I have some redesigning to do.
Jerry
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