X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao02.cox.net ([68.230.241.37] verified) by logan.com (CommuniGate Pro SMTP 4.3.5) with ESMTP id 1023719 for flyrotary@lancaironline.net; Mon, 27 Jun 2005 16:15:05 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.37; envelope-from=ALVentures@cox.net Received: from BigAl ([68.7.14.39]) by fed1rmmtao02.cox.net (InterMail vM.6.01.04.00 201-2131-118-20041027) with ESMTP id <20050627201418.DVXD22430.fed1rmmtao02.cox.net@BigAl> for ; Mon, 27 Jun 2005 16:14:18 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: NPG + use in aircraft?? Date: Mon, 27 Jun 2005 13:14:30 -0700 Message-ID: <000701c57b54$d38bf000$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01C57B1A.272D1800" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 This is a multi-part message in MIME format. ------=_NextPart_000_0008_01C57B1A.272D1800 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 George B.; =20 Nucleate boiling (small steam bubbles forming and dissipating) provides = the highest heat transfer coefficient from the surface to the coolant; = better than no boiling. Film boiling, on the other hand, is when there is a = layer of steam between surface and coolant, and the heat transfer coefficient drops precipitously. The occurrence of film boiling is a very bad = thing, causes serious hot spots in the walls, and can damage the engine. =20 Al G. =20 P.S. Can we dis the background on these messages? =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Echo Lake Fishing Resort (Georges Boucher) Sent: Monday, June 27, 2005 11:51 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: NPG + use in aircraft?? =20 Rusty "boiling removes heat" I have a hard time understanding that quote. When racers started using PG they were able to run 15:1 compression on "pump" fuel=20 due to the fact that boiling coolant created hot spots in the = combustion chambers & in turn causes pre-ignition (they also reversed the coolant = flow direction to bring the cooled coolant to the hottest part of the system, = & all this with no pressure cap. The one disadvantage I see in the 13b is = that it can't handle the potential higher boiling point of PG. I have a 3.0 L = V6 that I reversed the cooling system on to use in the Christavia (that was before I got hooked on the 13B) Georges B. -------Original Message------- =20 From: Rotary motors in aircraft =20 Date: 06/27/05 12:13:55 To: Rotary motors in aircraft =20 Subject: [FlyRotary] Re: NPG + use in aircraft?? =20 Has anyone used the NPG+ coolant in an aircraft? What are the pros and cons? =20 =20 NPG+ is standard issue in the 912S, and perhaps the 912 also. If I'm = not mistaken, Dave Leonard is running NPG+ now, and I'm running NPG-R. =20 =20 The Evan's marketing folks can give you way more pros than I can think = of, but I do think it's working very well. The primary benefit is the fact = that it's native boiling point is in the 375F range, so you don't have to = worry about a cascade effect of boil over if you unexpectedly run hot, lose pressure, etc. It's also not supposed to be subject to localized = boiling around hot spots in the engine. Evan's claims this as a big benefit, = but others, such as Tracy, think this boiling helps remove heat. It's a bit more environmentally friendly too, so it won't hurt the rats in John's hanger. =20 =20 The high boiling temp means that you don't need to run a pressurized = system, which is my favorite part. There's less stress on the system, and any = leak that occurs, will be much slower (initially) than if there was pressure. = I added an air separator tank, with a level sensor inside, so if I get a = leak, I'll know about it before it gets to the level of the top of the engine. That was the best detection method I could think of.=20 =20 The down side is the cost, and the fact that it doesn't transfer heat as effectively as traditional EG/water mix. Your temps will almost = certainly go up some, but at least you won't boil over. =20 =20 If the oil temp is below 180 F but the coolant is above 220F, is this detrimental to the 13B??=20 =20 Define "above" :-) I don't think there's anything harmful about 220F, = or a bit over that for coolant, since cars do it all the time. I believe the power will be reduced a bit at those temps though, and perhaps there = will be more wear on the engine. I've heard that, but can't say if it's significant, or even true. =20 =20 Cheers, Rusty=20 =20 =20 =20 =20 =20 ------=_NextPart_000_0008_01C57B1A.272D1800 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

George B.;

 

Nucleate boiling (small steam = bubbles forming and dissipating) provides the highest heat transfer coefficient = from the surface to the coolant; better than no boiling.  Film boiling, = on the other hand, is when there is a layer of steam between surface and = coolant, and the heat transfer coefficient drops precipitously.  The occurrence = of film boiling is a very bad thing, causes serious hot spots in the walls, and = can damage the engine.

 

Al G.

 

P.S.  Can we dis the = background on these messages?

 

-----Origi= nal Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Echo Lake Fishing Resort (Georges Boucher)
Sent: Monday, June 27, 2005 11:51 AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = NPG + use in aircraft??

 

Rusty

"boiling removes heat" I have a = hard time understanding that quote. When racers started using PG they were able = to run 15:1 compression on "pump" fuel 

 due to the fact that boiling coolant = created hot spots in the combustion chambers & in turn causes pre-ignition = (they also reversed the coolant flow direction to bring the cooled coolant = to the hottest part of the system, & all this with no pressure cap. The = one disadvantage I see in the 13b is that it can't handle the potential = higher boiling point of PG. I have a 3.0 L V6 that I reversed the cooling system on = to use in the Christavia (that was before I got hooked on the = 13B)

Georges B.

-------Original = Message-------

 

Date: 06/27/05 = 12:13:55

Subject: [FlyRotary] Re: NPG + use = in aircraft??

 

Has anyone used the NPG+ coolant in an aircraft?  What are the pros and = cons?   

 

NPG+ is standard issue in = the 912S, and perhaps the 912 also.  If I'm not mistaken, Dave = Leonard is running NPG+ now, and I'm running = NPG-R.   

 

The Evan's marketing folks = can give you way more pros than I can think of, but I do think it's = working very well.  The primary benefit is the fact that it's native boiling point is in the 375F range, so you don't have = to worry about a cascade effect of boil over if you unexpectedly run hot, = lose pressure, etc.  It's also not supposed to be subject to localized boiling around hot spots in the engine.  Evan's claims this as a = big benefit, but others, such as Tracy, think this boiling helps remove heat.  It's a bit more environmentally friendly too, so it = won't hurt the rats in John's = hanger.      

 

The high boiling temp means = that you don't need to run a pressurized system, which is my favorite = part.  There's less stress on the system, and any leak that occurs, will be = much slower (initially) than if there was pressure.   I added an = air separator tank, with a level sensor inside, so if I get a leak, I'll = know about it before it gets to the level of the top of the engine.  = That was the best detection method I could think = of. 

 

The down side is the cost, = and the fact that it doesn't transfer heat as effectively as traditional = EG/water mix.  Your temps will almost certainly go up some, but at least = you won't boil over.    

 

 If the oil temp is below 180 F but = the coolant is above 220F, is this detrimental to the 13B?? 

 

Define "above" = :-)   I don't think there's anything harmful about 220F, or a bit over that = for coolant, since cars do it all the time.  I believe the power = will be reduced a bit at those temps though, and perhaps there will be more = wear on the engine.  I've heard that, but can't say if it's significant, or even true. 

 

Cheers,

Rusty

 

 

 

 

 

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