Return-Path: Received: from [216.52.245.18] (HELO ispwestemail1.aceweb.net) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2629921 for flyrotary@lancaironline.net; Thu, 09 Oct 2003 08:48:25 -0400 Received: from 7n7z201 (unverified [208.187.45.41]) by ispwestemail1.aceweb.net (Vircom SMTPRS 2.1.268) with SMTP id for ; Thu, 9 Oct 2003 05:53:56 -0700 Message-ID: <03a701c38e63$e39c8ca0$252dbbd0@7n7z201> From: "William" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: EWP - Success at last? Date: Thu, 9 Oct 2003 07:50:01 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_03A2_01C38E39.F1AC8040" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4133.2400 X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4133.2400 This is a multi-part message in MIME format. ------=_NextPart_000_03A2_01C38E39.F1AC8040 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Ok, a couple more points to make. 1. Todd has done something very useful, *started* getting performance = data with the EWP. 2. What was the outside temperature? This makes a difference, because = there are two ways you can get enough cooling -- really cool the water = down before it goes into the engine, with a small flow rate, or use a = higher flow rate and a smaller delta T. The first will work in cooler = weather, he may be flow limited in hotter weather. Time and *testing* = will tell. 3. The actual horsepower required to pump water through the system is = *not* all that much. I will post some results later today that I derived = from my *actual tests* on an engine driven pump mounted on the block. = (on different computer). Dale and Jim make a good point about the water = pump thrashing when the thermostat closes -- drives up the power = required. 4. with respect to the quote below, I have long suspected that Davies = Craig would be looking for a measurement of engine power saved that made = their EWP look as favorable as possible. So they *might* quote the = highest power drain that a water pump could absorb.=20 5. As I stated before, when I was testing the stock pump by driving it = with an electric motor, I could easily drive it with my table-saw motor = up to 5400 rpm. Paul wanted to see what it would do at 7000 rpm, so he = sent me a larger pulley, and I tried it. That increased the power = requirement enough that the motor would blow the circuit breaker. The = power absorbed by the pump clearly goes up as the square (or cube?) of = the RPM, so don't overspeed your pumps! As another point to be considered, there has been previously discussed = the need for higher volume flows to prevent local hot spots around the = spark plugs from causing local boiling. I am not sure how to test this = in the EWP case. Bill Schertz=20 <... "up to 30 HP." ... current drain is .134 HP ... Maximum flow rate = of [the EWP is] only 88L/min compared with a maximum of 240L/min for the = same engine using an older mechanical water pump design ...>=20 Beware people with an agenda - like "... figures don't lie, but liars = figure ... Most folks with an agenda will exaggerate to make a point. =20 ------=_NextPart_000_03A2_01C38E39.F1AC8040 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Ok, a couple more points to = make.

1. Todd has done something very useful, = *started*=20 getting performance data with the EWP.

2. What was the outside temperature? = This makes a=20 difference, because there are two ways you can get enough cooling -- = really cool=20 the water down before it goes into the engine, with a small flow rate, = or use a=20 higher flow rate and a smaller delta T. The first will work in = cooler=20 weather, he may be flow limited in hotter weather. Time and *testing* = will=20 tell.

3. The actual horsepower required to = pump water=20 through the system is *not* all that much. I will post some results = later today=20 that I derived from my *actual tests* on an engine driven pump mounted = on the=20 block. (on different computer). Dale and Jim make a good point about the = water=20 pump thrashing when the thermostat closes -- drives up the power=20 required.

4. with respect to the quote below, I = have long=20 suspected that Davies Craig would be looking for a measurement of engine = power=20 saved that made their EWP look as favorable as possible. So they *might* = quote=20 the highest power drain that a water pump could absorb.

5. As I stated before, when I was = testing the stock=20 pump by driving it with an electric motor, I could easily drive it with = my=20 table-saw motor up to 5400 rpm. Paul wanted to see what it would = do at=20 7000 rpm, so he sent me a larger pulley, and I tried it. That increased = the=20 power requirement enough that the motor would blow the circuit = breaker. =20 The power absorbed by the pump clearly goes up as the square (or cube?) = of the=20 RPM, so don't overspeed your pumps!

As another point to be considered, = there has been=20 previously discussed the need for higher volume flows to prevent local = hot spots=20 around the spark plugs from causing local boiling. I am not sure = how to=20 test this in the EWP case.

Bill Schertz

<... "up to 30 HP." ... = current drain=20 is .134 HP ... Maximum flow rate of [the EWP is] only 88L/min compared = with a=20 maximum of 240L/min for the same engine using an older mechanical = water pump=20 design ...>
Beware people=20 with an agenda - like "... figures don't lie, but liars figure=20 ...

Most folks with an agenda = will=20 exaggerate to make a point.

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