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I seem to have missed a lot of posts. When I'm going to be out of town for more than couple of days I stop the list. That could explain some of it. 12 GPM and 34 GPM is a pretty wide window of stuff that apparently works. 34 is like cycling your whole coolant supply through the system every 4 seconds or so. That just seems really really fast to me. It was 40+ years ago last time I studied this stuff, so all I've got is intuitive guesses.
Which is, of course, exactly what I keep complaining about :o) ... Jim S.
Bob White wrote:
Hi Jim,
Bill Schertz has made the acutal flow measurements by driving his EDWP
with an electric motor. The EDWP can push 34 GPM thru two parallel
evaporator cores at 5600 rpm. Todd Bartrim is seeing over 9 gpm with an
EWP (Davies- Craig) only system (but that was at 12 V). I have measured
the flow in my engine with two EWP (Meziere WP136) and two GM evap
cores at about 11-12 GPM. I have "calculated that a WP336 should give
me about 16 GPM.
That sums up the measurements I know about. I have just about decided
to get the WP336 and run my system on 16 GPM. I am a little cautious
about the 12 GPM flow even though Todd is doing OK with less. Living
in New Mexico, I might encounter harsher conditons. :)
Bob W. (Working hard at collecting hard data.)
On Sun, 20 Mar 2005 14:40:46 -0600
Jim Sower <canarder@frontiernet.net> wrote:
Wasn't someone talking about the 12-16 GPM his EWP was pumping through his [not running, no EDWP] engine? Assuming 2-3 gal capacity, that circulates every bit of coolant through the system 5 or 6 times per minute. That's an entire cycle of coolant every 10 seconds or less. That sounds pretty fast to me.
Does anyone actually know what the flow through a rotary is with EDWP? I mean, like measured (the other list can be relied upon to calculate stuff). Just as important, does anyone actually know how far open/closed a thermostat is in our applications. I know some folks don't have thermostats installed. Is it possible that EDWP might be circulating coolant so fast it doesn't have time to cool off much in the radiator or heat up much in the block? That the same system would work as well at lower flow? Or something like that? It seems to me that all this quibbling about Beemer power levels on the autobahn ignore the obvious fact that as Leon has attested, EWP works quite well on the race tracks of Oz. I would hazard a guess that the stress on the system (WOT nearly all the time, maybe 1/3 the Q through the cooling system, SL summer temps rather than cruising much faster (3x the Q) at 80% at much higher/cooler altitudes) would hold a lot more water than a bunch of Beemer marketing brochures. The other list is forever making pronouncements about what will or will not work. Their math is impeccable. The premises they operate from are not Is it not possible that we are overlooking or underemphasizing some important factor? That the hybrid (EWP and EDWP) systems we have online now are distorting the data? Leon's experience cannot ignore any of the factors. Our estimates can ignore as many as we want to (or are unaware of). I can't help but think that a little morel hard data gathered from a purely EWP system will put a lot of the controversy to rest.
A flawless line of reasoning, based on a false premise leads us right through the lookin' glass ...
Jim S.
Leon wrote:
----- Original Message -----
From: Al Gietzen
To: Rotary motors in aircraft
Sent: Sunday, March 20, 2005 5:45 PM
Subject: [FlyRotary] Re: BMW and EWP
In a message dated 3/18/2005 11:24:08 PM Pacific Standard Time, ALVentures@cox.net writes:
Let’s say the rated hp is at 4800 rpm. The only time you approach rated power with this car is WOT at 4800 rpm at sealevel on a 60F day. How long would you ever sustain that condition.
Al
Al, How about 100mph for 20 minutes on the autoban?
Bill
Ah-h-h-h; you’re getting close now. That‘s probably about 80% power. But you’d probably have to stop once to pay a toll, and slow down for the Opal that’s driving in the left laneJ. Or maybe they don’t sell the EWP version in Germany.
All
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