X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-03.southeast.rr.com ([24.25.9.102] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with ESMTP id 1231454 for flyrotary@lancaironline.net; Mon, 10 Jul 2006 17:44:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.102; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-111-186.carolina.res.rr.com [24.74.111.186]) by ms-smtp-03.southeast.rr.com (8.13.6/8.13.6) with SMTP id k6ALhqmM021269 for ; Mon, 10 Jul 2006 17:43:53 -0400 (EDT) Message-ID: <000901c6a469$f7a36600$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Temperature control Date: Mon, 10 Jul 2006 17:44:05 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 X-Virus-Scanned: Symantec AntiVirus Scan Engine Steve, with equivalent OATs, if I make a full stop landing and taxi back and then take off. Under those conditions I will see around 180F for both oil and coolant by the time I am back to take off position. But, its about a quarter mile back from my point exiting runway for a taxi way and then back to take off position. So with taxi rpm my temperatures do not elevate. But, I will see 200F on the oil and perhaps 210-220F on the coolant after take off under those conditions. While both our temps are above the nominal recommended, I have found that for short duration, there does not APPEAR to be any problem. I know Tracy encounters (or did with the old 13B) the same conditions with no apparent problems. I think we would both feel a bit more comfortable with temps that stayed below 200F (and I do use that as my max red line for oil), they only way I know to do that is to size your coolant system for climb conditions which means it will be oversized for cruise with resulting excessive drag. My 0.02 Ed ----- Original Message ----- From: "Steve Brooks" To: "Rotary motors in aircraft" Sent: Monday, July 10, 2006 2:10 PM Subject: [FlyRotary] Re: Temperature control > Ed, > While you're on the subject of cooling, I have a > question. > > What are you temps on takeoff when you are starting > with a hot engine ? > > This weekend, I flew and the OAT on takeoff was about > 75 F. Climbing up about 1500 AGL my coolant was at > 200 and oil about 180. Both stabilized at about 190 > in level flight. > > I landed to check thing out and temps on shut down > were about 160. Cooled off some on decent. > > After sitting for 20 minutes or so, start up showed > about 185 and taxing to the runway. coolant was about > 200 when starting the takeoff roll. Climb to about > 1000 AGL had the coolant up to 220, and oil about 200. > I reduced power and continued a slow cruise climb > (about 200 fpm). The temps came down withing 2-3 > minutes to below 200, and stabilized to about 190 > after 5 minutes or so. > > Does this seem reasonable, or are my temps running a > bit high ? I have always seemed to have temperature > problems when starting out with a hot engine. > > Just wondering about what is normal. > > Steve Brooks > > > --- Ed Anderson wrote: > >> >> ----- Original Message ----- >> From: James Maher >> To: Rotary motors in aircraft >> Sent: Monday, July 10, 2006 1:28 PM >> Subject: [FlyRotary] Temperature control >> >> >> The setup: >> · Engine/Model/Year: 13B 6 port NA mixed >> · Source Condition: David Atkins Rebuilt >> for Aviation Application >> · Modifications: Ported intakes and cooling >> for 180HP >> · Intake: Atkins short manifold w/TWM 48mm >> Throttle body >> · Exhaust: 321 SS tangential muffler >> · Engine Control: RWS EC2 >> · Fuel Control: 4 Mazda 460cc Injectors, >> pri. in block & sec in manifold >> · Fuel Pumps: RWS >> · Cooling System: 2 - 9"x13"GM evaporator >> cores with 0.75" auto hose, stock water pump with >> 180F deg.-thermostat, 50/50 glycol\water mix. >> · Oil System: stock 1986 oil cooler >> · Installation: conventional - self built >> mount >> · PSRU/Re-Drive: Ross 2.85:1 >> · Prop: IVO Magnum 74" 45-105"pitch >> in-flight adjustable >> · Power: 180HP? >> >> The issue: >> On the ground, cooling stabilizes at 180-190F deg >> and oil is usually 10 degrees below the cooling with >> an OAT of 65-70F deg. >> When running with higher OAT (75-85F deg) after >> about 0.5 hours of moderate taxi runs (up to >> 4300RPM) the cooling temps reach 212Fdeg with the >> oil about 200F deg. >> >> The question: >> Can something be done to get lower operating >> temperatures without redesigning the system? >> Would switching to pure water help and if so by >> how much? >> Would removing the thermostat help and if so by >> how much? >> How much change should I expect if I were to do >> both? >> You guys down south should have a good idea of how >> best to enhance cooling. >> What are your suggestions? >> Thanks, >> Jim Maher(Dyke Delta) >> >> >> Hi James, >> >> Welcome to the club, cooling appears to always be >> the first item of business. I can not quantify the >> differences those changes you propose would make. >> >> However, a 50/50 coolant mixture has a 40% lower >> specific heat than pure water alone. Meaning it >> will not carry as much heat away at the same coolant >> temperature. Would pure water give you 40% more >> cooling - I personally doubt it, would it help, I >> believe it certainly would. >> >> I fly without a thermostat and my normal (60-70 F >> OAT) temps are 160F for coolant and oil at cruise. >> On a hot day, right after take off, I may hit 200F >> on the oil and 220F on the coolant for a short >> duration. With a thermostat, your coolant temps >> are going to go right up to the thermostat limits >> shortly after starting your engine - after all that >> is what a thermostat does. But, still at moderate >> rpm of 4300 on a 60-70F day, I would like for the >> coolant and oil not to exceed 200F. >> >> I fly without a thermostat to remove any flow >> restriction as well as permitting my temps to stay >> below any thermostat limit if conditions permit. >> Since I get acceptable temperatures when flying I am >> satisfied without a thermostat. In winter, the >> temps do run a bit cool, but then I can tape off a >> bit of the core and get higher temps. >> >> Ed >> >> >> That's my 0.02 worth >> >> Ed >> >> > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >