X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qw-out-2122.google.com ([74.125.92.27] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3819181 for flyrotary@lancaironline.net; Thu, 20 Aug 2009 08:49:33 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.92.27; envelope-from=rwstracy@gmail.com Received: by qw-out-2122.google.com with SMTP id 3so1576678qwe.25 for ; Thu, 20 Aug 2009 05:48:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=y3WilriMljpx2kaxnwu4TsHqKoPsSKUT9XWAzQBqWIg=; b=U961adgB+JLQszMeWI5ssXYMK3gclflG+5LeTRPg444TyxiWldm8kPtrIptL0YXu8m CdmAgtPyQQz/EL/jyKbZTJaiH2SOMFueDDs818fH4U6Cjlc5T2wmZX76w77CJk4fS/C2 e4dsnr4OEUkWYTJkrKCmWdA0c4CHfQnfEdBOE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=gC9nz16ujmkJbYbH8tXJQg7lgwTc8N6h8O7LXyZLXpvFxcSJWAbzgrtWA2mcQoEouV VJBYyXXfndd6B/QM4Q2ST5mqIm89+ERGbK15tekuWIO/7wraM7qJEWJAvKPjpWrMB9C8 zZ5oys6bSGaRiTL10KngkSVEF2JC5kJb1bmYo= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.42.75 with SMTP id r11mr7399736qae.321.1250772536582; Thu, 20 Aug 2009 05:48:56 -0700 (PDT) In-Reply-To: References: Date: Thu, 20 Aug 2009 08:48:56 -0400 X-Google-Sender-Auth: 34b29abd476039b0 Message-ID: <1b4b137c0908200548v693afffdxa1947ca47dc5c3b3@mail.gmail.com> Subject: Re: [FlyRotary] Re: back in the air From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000feaf1dc99bce39f0471922cf9 --000feaf1dc99bce39f0471922cf9 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit "So far its looking like I could stand to shrink both inlets a little - maybe a lot. " Mike, Glad your EC2 & cooling issues are under control. I'd go with a cowl flap to restrict air flow (and increase exit velocity) rather than reduce inlet size. Probably less fiberglass work for the cowl flap as well. Won't go into the mind numbing formulas and laws that govern the principal but here is what I have boiled them down to: It is not the absolute SIZE of the cooling inlet that determines drag but the *amount of air that goes through it*. Main thing is to make sure the air that is diverted around the inlet has a clean path. (you've done a good job there). Restricting the inlet will also restrict the flow but why reduce your options for other conditions (hot weather, max climb, etc). Tracy On Wed, Aug 19, 2009 at 11:30 PM, Mike Wills wrote: > I seriously considered a water oil exchanger. Fluidyne also made some of > those that looked really good. Dont know if they still do. > > Ultimately decided not to go that route. So many people were having cooling > issues when I was designing my system and it seemed that using seperate air > oil exchangers would ease potential debug hassles. > > I'm mostly happy with my choice. Its working well so far. And using a $25 > wrecking yard RX-7 oil cooler was about as cheap as it gets. My only > complaints so far are that I am not real happy with the looks of the extra > scoop I added for the oil cooler, and my braided stainless oil cooler lines > are fairly long and heavy. > > I probably will redo the cowl somewhere down the road after I get a good > handle on just how well the cooling is on hot days. So far its looking like > I could stand to shrink both inlets a little - maybe a lot. On my flight the > other day coolant temp never went over 180. And that included taxi from the > extreme west end of the airport to the other end of an 8000' runway. > > Mike Wills > RV-4 N144MW > > ----- Original Message ----- > *From:* MONTY ROBERTS > *To:* Rotary motors in aircraft > *Sent:* Wednesday, August 19, 2009 6:58 AM > *Subject:* [FlyRotary] Re: back in the air > > Mike, > > Great to hear you are flying again. > > I don't know if you have seen some of the new water/oil heat exchangers?. > They mount in the tank of the water radiator. The preferred installation > would be a dual pass water rad where the front tank is divided. The water > flows through 1/2 of the radiator and gets cooled off. Then it flows through > the end tank past the oil cooler picking up heat. Then it flows back through > the second half of the radiator and gets cooled off again and finally gets > returned to the engine. This solves the "which hose do I put the oil cooler > in" dilemma. It also can greatly simplify the ductwork and make the radiator > more efficient. If you are thinking about re-doing your cowl, it might solve > some of your problems. > > Monty > > ----- Original Message ----- > *From:* Mike Wills > *To:* Rotary motors in aircraft > *Sent:* Wednesday, August 19, 2009 12:01 AM > *Subject:* [FlyRotary] back in the air > > Finally. I'm confident that the reseat of the B controller chip solved my > problem with spontaneous loss of data. I flew for 1.5 hours last friday. > Engine running great and staying cool. Minor issues with the radio, landing > gear shimmy on the landing, and still dont have the rudder trim right. But > getting closer. Hope to get serious now about getting this thing working now > that summer (and the soaring season) are winding down. Too many hobbies. > > Mike Wills > RV-4 N144MW > > ------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.392 / Virus Database: 270.13.61/2312 - Release Date: 08/18/09 > 18:05:00 > > --000feaf1dc99bce39f0471922cf9 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable "So=20 far its looking like I could stand to shrink both inlets a little - maybe a= lot. "

Mike,
Glad your EC2 & cooling issues are = under control.=A0 I'd go with a cowl flap to restrict air flow (and inc= rease exit velocity) rather than reduce inlet size.=A0=A0 Probably less fib= erglass work for the cowl flap as well.

Won't go into the mind numbing formulas and laws that govern the pr= incipal but here is what I have boiled them down to:

It is not the a= bsolute SIZE of the cooling inlet that determines drag but the amount of= air that goes through it.

=A0 Main thing is to make sure the air that is diverted around the inle= t has a clean path.=A0 (you've done a good job there).=A0 Restricting t= he inlet will also restrict the flow but why reduce your options for other = conditions (hot weather, max climb, etc).

Tracy

On Wed, Aug 19, 2009 at 11:30 P= M, Mike Wills <rv-= 4mike@cox.net> wrote:
I seriously considered a water oil exc= hanger.=20 Fluidyne also made some of those that looked really good. Dont know if they= =20 still do.
=A0
Ultimately decided not to go that rout= e. So many=20 people were having cooling issues when I was designing my system and it see= med=20 that using seperate air oil exchangers would ease potential debug=20 hassles.
=A0
I'm mostly happy with my choice. I= ts working well=20 so far. And using a $25 wrecking yard RX-7 oil cooler was about as cheap as= it=20 gets. My only complaints so far are that I am not real happy with the looks= of=20 the extra scoop I added for the oil cooler, and my braided stainless oil co= oler=20 lines are fairly long and heavy.
=A0
I probably will redo the cowl somewher= e down the=20 road after I get a good handle on just how well the cooling is on hot days.= So=20 far its looking like I could stand to shrink both inlets a little - maybe a= lot.=20 On my flight the other day coolant temp never went over 180. And that inclu= ded=20 taxi from the extreme west end of the airport to the other end of an 8000&#= 39;=20 runway.
=A0
Mike Wills
RV-4 N144MW
----- Original Message -----
From:=20 MONTY ROBERTS
Sent: Wednesday, August 19, 2009 6= :58=20 AM
Subject: [FlyRotary] Re: back in t= he=20 air

Mike,
=A0
Great to hear you are flying again.<= /font>
=A0
I don't know if you have seen so= me of the new=20 water/oil heat exchangers?. They mount in the tank of the water radiator.= The=20 preferred installation would be a dual pass water rad where the front tan= k is=20 divided. The water flows through 1/2 of the radiator and gets cooled off.= Then=20 it flows through the end tank past the oil cooler picking up heat. Then i= t=20 flows back through the second half of the radiator and gets cooled off ag= ain=20 and finally gets returned to the engine. This solves the "which hose= do I put=20 the oil cooler in" dilemma. It also can greatly simplify the ductwor= k and make=20 the radiator more efficient. If you are thinking about re-doing your cowl= , it=20 might solve some of your problems.
=A0
Monty
----- Original Message -----
From:=20 Mike Wills=20
Sent: Wednesday, August 19, 2009= 12:01=20 AM
Subject: [FlyRotary] back in the= =20 air

Finally. I'm confident that th= e reseat of the B=20 controller chip solved my problem with spontaneous loss of data. I flew= for=20 1.5 hours last friday. Engine running great and staying cool. Minor iss= ues=20 with the radio, landing gear shimmy on the landing, and still dont have= the=20 rudder trim right. But getting closer. Hope to get serious now about ge= tting=20 this thing working now that summer (and the soaring season) are winding= =20 down. Too many hobbies.
=A0
Mike Wills
RV-4 N144MW


No virus found in this incoming message.
Checked by AVG -= =20 www.avg.com
Ve= rsion: 8.5.392 / Virus Database: 270.13.61/2312 - Release=20 Date: 08/18/09 18:05:00

--000feaf1dc99bce39f0471922cf9--