REFLECTOR: Ceramic Coating
Unterreiner
naomi at yadtel.net
Mon Feb 19 15:14:37 CST 2007
I have 540 cylinders with the exhaust coming out the top. Is there any
chance of the coating coming off? I also wouldn't want to use it in the
intake pipes if there was a chance it could come off.
Dean Unterreiner
----- Original Message -----
From: <reflector-request at tvbf.org>
To: <reflector at tvbf.org>
Sent: Monday, February 19, 2007 3:43 PM
Subject: Reflector Digest, Vol 33, Issue 73
> Send Reflector mailing list submissions to
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> Today's Topics:
>
> 1. Re: Exhaust wrap (Alex)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 19 Feb 2007 14:43:38 -0600
> From: "Alex" <alex157 at pwhome.com>
> Subject: Re: REFLECTOR: Exhaust wrap
> To: "'Velocity Aircraft Owners and Builders list'"
> <reflector at tvbf.org>
> Message-ID: <000501c75466$a2812b00$6401a8c0 at ALEX>
> Content-Type: text/plain; charset="us-ascii"
>
> I coated my pipes both sides with ceramic also- looks like chrome which is
> nice, the pipes still get pretty hot, but not as how as steel alone, as
> for
> the wrap, I have used it successfully with some construction equipment
> that
> runs every day, stays out in the rain and have had not problems with the
> pipes rotting and they are mild steel pipes with no coating- these pipes
> you
> definitely can hold when the engine is running- although diesels run a lot
> cooler than gas, they still get pretty hot.........
>
> _____
>
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of nmflyer1 at aol.com
> Sent: Sunday, February 18, 2007 7:05 PM
> To: reflector at tvbf.org
> Subject: Re: REFLECTOR: Exhaust wrap
>
>
> One thing I did on my V-6 velocity pipes: I took them to a local ceramic
> coating place and had them coated inside and out. The race car folks swear
> by this approach, to the extent that some say they have
> put their hand on a header tube while it is up to temp and didnt get
> burned.
> Im not sure who got drunk enough to try this, but if it works half that
> good, I'd say it's a plus. Coating both the inside and outside of the
> pipes
> works best (pretty easy on my exhaust system). I got both mine done for
> about $200.00
>
> Kurt
>
>
> -----Original Message-----
> From: naomi at yadtel.net
> To: reflector at tvbf.org
> Sent: Sun, 18 Feb 2007 5:33 PM
> Subject: Re: REFLECTOR: Exhaust wrap
>
>
> I was considering trying exhaust wraps, but heard they didn't make any
>
> difference and had negative effects on the pipes. The race car accessory
>
> shops sell a loose fitting exhaust pipe heat shield which may work just as
>
> well and would be better on the pipes and allow for easier inspection. Let
>
> us know if the wraps make any difference.
>
>
>
> Dean Unterreiner
>
> ----- Original Message -----
>
> From: <reflector-request at tvbf.org <javascript:parent.ComposeTo(> >
>
> To: <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
> Sent: Sunday, February 18, 2007 7:18 PM
>
> Subject: Reflector Digest, Vol 33, Issue 61
>
>
>
>
>
>> Send Reflector mailing list submissions to
>
>> reflector at tvbf.org <javascript:parent.ComposeTo(>
>
>>
>
>> To subscribe or unsubscribe via the World Wide Web, visit
>
>> http://www.tvbf.org/mailman/listinfo/reflector
>
>> or, via email, send a message with subject or body 'help' to
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>> reflector-request at tvbf.org <javascript:parent.ComposeTo(>
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>>
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>> You can reach the person managing the list at
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>>
>
>> When replying, please edit your Subject line so it is more specific
>
>> than "Re: Contents of Reflector digest..."
>
>>
>
>>
>
>> Today's Topics:
>
>>
>
>> 1. Exhaust wrap. was updraft cooling (Scott Derrick)
>
>> 2. Exhaust wrap. was updraft cooling (Scott Derrick)
>
>> 3. Re: Updraft cooling (Unterreiner)
>
>>
>
>>
>
>> ----------------------------------------------------------------------
>
>>
>
>> Message: 1
>
>> Date: Sun, 18 Feb 2007 17:15:37 -0500 (EST)
>
>> From: "Scott Derrick" <scott at tnstaafl.net <javascript:parent.ComposeTo(>
>> >
>
>> Subject: REFLECTOR: Exhaust wrap. was updraft cooling
>
>> To: velocity at davebiz.com <javascript:parent.ComposeTo(> , "Velocity
> Aircraft Owners and Builders list"
>
>> <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>> Message-ID: <49344.75.6.245.222.1171836937.squirrel at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>> Content-Type: text/plain;charset=iso-8859-1
>
>>
>
>> I tried that when I had updraft cooling. I was having major cooling
>
>> issues so I wrapped the exhaust. Had no effect at all on my cooling.
>> I've
>
>> been told it also can cause your pipes to corrode faster over time.
>
>>
>
>> The fix for my cooling woes was to get absolutely fanatical about tight
>
>> baffling, temps dropped 75 degrees.
>
>>
>
>> Scott
>
>>
>
>>> Chuck, I think you're right. My A&P suggested that I wrap the exhaust
>
>>> pipes with insulating fabric (appears to be made from fiberglass) on my
>
>>> updraft system. This should keep the heat more contained in the pipes
>
>>> and exhausting outside of the plane. I have not flown yet since
>
>>> wrapping so I can't tell you how much it affects temps.
>
>>>
>
>>> Chuck Jensen wrote:
>
>>>> I've not seen the layout of an updraft cooling system, but does the
>
>>>> air get preheated from passing by the exhaust pipes before it every
>
>>>> gets to the cylinder heads? If it does, that would greatly increase
>
>>>> the volume of air required because of the reduced delta T across the
>
>>>> heads. By comparison the top NACAs provide clean, cool air directly
>
>>>> to the CHs. Too simple--I must be missing something?
>
>>>>
>
>>>> Chuck Jensen
>
>>>> * *
>
>>>> -----Original Message-----
>
>>>> *From:* reflector-bounces at tvbf.org <javascript:parent.ComposeTo(>
> [mailto:reflector-bounces at tvbf.org <javascript:parent.ComposeTo(> ]
>
>>>> *On Behalf Of *John Dibble
>
>>>> *Sent:* Saturday, February 17, 2007 2:41 PM
>
>>>> *To:* Velocity Aircraft Owners and Builders list
>
>>>> *Subject:* Re: REFLECTOR: updraft cooling
>
>>>>
>
>>>> I think the amount of air going past the cylinders will determine the
>
>>>> degree of cooling, so it's a matter of making the NACA or armpit scoop
>
>>>> and ducts big enough for sufficient air.
>
>>>>
>
>>>> John
>
>>>>
>
>>>> Ron Brown wrote:
>
>>>>
>
>>>>> And, the downdraft NACA cooling for some unexplainable reason, runs
>
>>>>> about 40 degrees cooler than the updraft cooling. Mark Machado
>
>>>>> converted what is now the factory trainer from updraft to downdraft
>
>>>>> and says the heads ran 30-40 degrees cooler. My 173 Elite RG runs
>
>>>>> 360-370 max on a long climb out and 320-340 degrees during a 2600
>
>>>>> rpm/155 kt cruise. I highly recommend the NACA cooling system.
>
>>>> ------------------------------------------------------------------------
>
>>>>
>
>>>> _______________________________________________
>
>>>> To change your email address, visit
>
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>>
>
>>>> Visit the gallery! www.tvbf.org/gallery
>
>>>> user:pw = tvbf:jamaicangoose
>
>>>> Check new archives: www.tvbf.org/pipermail
>
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>>>
>
>>> --
>
>>> Dave Philipsen
>
>>> Velocity STD-FG
>
>>> N83DP
>
>>>
>
>>>
>
>>> _______________________________________________
>
>>> To change your email address, visit
>
>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>
>
>>> Visit the gallery! www.tvbf.org/gallery
>
>>> user:pw = tvbf:jamaicangoose
>
>>> Check new archives: www.tvbf.org/pipermail
>
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>>>
>
>>
>
>>
>
>>
>
>> ------------------------------
>
>>
>
>> Message: 2
>
>> Date: Sun, 18 Feb 2007 17:15:42 -0500 (EST)
>
>> From: "Scott Derrick" <scott at tnstaafl.net <javascript:parent.ComposeTo(>
>> >
>
>> Subject: REFLECTOR: Exhaust wrap. was updraft cooling
>
>> To: velocity at davebiz.com <javascript:parent.ComposeTo(> , "Velocity
> Aircraft Owners and Builders list"
>
>> <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>> Message-ID: <49346.75.6.245.222.1171836942.squirrel at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>> Content-Type: text/plain;charset=iso-8859-1
>
>>
>
>> I tried that when I had updraft cooling. I was having major cooling
>
>> issues so I wrapped the exhaust. Had no effect at all on my cooling.
>> I've
>
>> been told it also can cause your pipes to corrode faster over time.
>
>>
>
>> The fix for my cooling woes was to get absolutely fanatical about tight
>
>> baffling, temps dropped 75 degrees.
>
>>
>
>> Scott
>
>>
>
>>> Chuck, I think you're right. My A&P suggested that I wrap the exhaust
>
>>> pipes with insulating fabric (appears to be made from fiberglass) on my
>
>>> updraft system. This should keep the heat more contained in the pipes
>
>>> and exhausting outside of the plane. I have not flown yet since
>
>>> wrapping so I can't tell you how much it affects temps.
>
>>>
>
>>> Chuck Jensen wrote:
>
>>>> I've not seen the layout of an updraft cooling system, but does the
>
>>>> air get preheated from passing by the exhaust pipes before it every
>
>>>> gets to the cylinder heads? If it does, that would greatly increase
>
>>>> the volume of air required because of the reduced delta T across the
>
>>>> heads. By comparison the top NACAs provide clean, cool air directly
>
>>>> to the CHs. Too simple--I must be missing something?
>
>>>>
>
>>>> Chuck Jensen
>
>>>> * *
>
>>>> -----Original Message-----
>
>>>> *From:* reflector-bounces at tvbf.org <javascript:parent.ComposeTo(>
> [mailto:reflector-bounces at tvbf.org <javascript:parent.ComposeTo(> ]
>
>>>> *On Behalf Of *John Dibble
>
>>>> *Sent:* Saturday, February 17, 2007 2:41 PM
>
>>>> *To:* Velocity Aircraft Owners and Builders list
>
>>>> *Subject:* Re: REFLECTOR: updraft cooling
>
>>>>
>
>>>> I think the amount of air going past the cylinders will determine the
>
>>>> degree of cooling, so it's a matter of making the NACA or armpit scoop
>
>>>> and ducts big enough for sufficient air.
>
>>>>
>
>>>> John
>
>>>>
>
>>>> Ron Brown wrote:
>
>>>>
>
>>>>> And, the downdraft NACA cooling for some unexplainable reason, runs
>
>>>>> about 40 degrees cooler than the updraft cooling. Mark Machado
>
>>>>> converted what is now the factory trainer from updraft to downdraft
>
>>>>> and says the heads ran 30-40 degrees cooler. My 173 Elite RG runs
>
>>>>> 360-370 max on a long climb out and 320-340 degrees during a 2600
>
>>>>> rpm/155 kt cruise. I highly recommend the NACA cooling system.
>
>>>> ------------------------------------------------------------------------
>
>>>>
>
>>>> _______________________________________________
>
>>>> To change your email address, visit
>
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>>
>
>>>> Visit the gallery! www.tvbf.org/gallery
>
>>>> user:pw = tvbf:jamaicangoose
>
>>>> Check new archives: www.tvbf.org/pipermail
>
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>>>
>
>>> --
>
>>> Dave Philipsen
>
>>> Velocity STD-FG
>
>>> N83DP
>
>>>
>
>>>
>
>>> _______________________________________________
>
>>> To change your email address, visit
>
>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>
>
>>> Visit the gallery! www.tvbf.org/gallery
>
>>> user:pw = tvbf:jamaicangoose
>
>>> Check new archives: www.tvbf.org/pipermail
>
>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>>>
>
>>
>
>>
>
>>
>
>> ------------------------------
>
>>
>
>> Message: 3
>
>> Date: Sun, 18 Feb 2007 19:17:55 -0500
>
>> From: "Unterreiner" <naomi at yadtel.net <javascript:parent.ComposeTo(> >
>
>> Subject: Re: REFLECTOR: Updraft cooling
>
>> To: <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>> Message-ID: <003a01c753bb$67b196f0$0a01a8c0 at DELL280IMAGE2>
>
>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>
>> reply-type=original
>
>>
>
>> Dave,
>
>>
>
>> Let me know if you come up with any ingenious ideas on your engine
>
>> cooling. My email is naomi at yadtel.net <javascript:parent.ComposeTo(> .
>
>>
>
>> Goodluck,
>
>> Dean Unterreiner
>
>>
>
>> ----- Original Message -----
>
>> From: <reflector-request at tvbf.org <javascript:parent.ComposeTo(> >
>
>> To: <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>> Sent: Sunday, February 18, 2007 11:30 AM
>
>> Subject: Reflector Digest, Vol 33, Issue 52
>
>>
>
>>
>
>>> Send Reflector mailing list submissions to
>
>>> reflector at tvbf.org <javascript:parent.ComposeTo(>
>
>>>
>
>>> To subscribe or unsubscribe via the World Wide Web, visit
>
>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>> or, via email, send a message with subject or body 'help' to
>
>>> reflector-request at tvbf.org <javascript:parent.ComposeTo(>
>
>>>
>
>>> You can reach the person managing the list at
>
>>> reflector-owner at tvbf.org <javascript:parent.ComposeTo(>
>
>>>
>
>>> When replying, please edit your Subject line so it is more specific
>
>>> than "Re: Contents of Reflector digest..."
>
>>>
>
>>>
>
>>> Today's Topics:
>
>>>
>
>>> 1. Re: Updraft cooling (John Dibble)
>
>>> 2. Re: CBs and fuses (John Tvedte)
>
>>>
>
>>>
>
>>> ----------------------------------------------------------------------
>
>>>
>
>>> Message: 1
>
>>> Date: Sun, 18 Feb 2007 10:27:36 -0600
>
>>> From: John Dibble <aminetech at bluefrog.com <javascript:parent.ComposeTo(>
>>
>
>>> Subject: Re: REFLECTOR: Updraft cooling
>
>>> To: velocity at davebiz.com <javascript:parent.ComposeTo(> , Velocity
> Aircraft Owners and Builders list
>
>>> <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>>> Message-ID: <45D87E78.9A701FF2 at bluefrog.com
> <javascript:parent.ComposeTo(> >
>
>>> Content-Type: text/plain; charset=us-ascii
>
>>>
>
>>> According to my Franklin engine manual, the measured CHT will be 50 C
>>> (90
>
>>> F) higher with a spark
>
>>> plug probe, located on the bottom plug, compared to a bayonet probe,
>
>>> located on the top of the
>
>>> cylinder. Maybe the temperature difference is due to the direction of
>
>>> air
>
>>> flow. I have downdraft
>
>>> cooling. The air should be much warmer after passing the cylinder.
>
>>> Therefore the temperature at
>
>>> the bottom of my cylinders should be higher than at the top. If the
>
>>> bayonet probe is used and
>
>>> cooling is switched from updraft to downdraft, a lower CHT may not
>
>>> necessarily mean the overall
>
>>> cylinder temp is lower. Just a thought.
>
>>>
>
>>> John
>
>>>
>
>>> Dave Philipsen wrote:
>
>>>
>
>>>> Dean,
>
>>>>
>
>>>> I'm in the same boat (plane) as you. I bought a Velocity that was
>>>> built
>
>>>> by someone else and it has updraft cooling too. But, I think that's
>>>> the
>
>>>> way they all were originally. The NACA scoops were introduced as
>
>>>> standard a little later. I'm in the midst of working on ways to cool
>>>> it
>
>>>> more efficiently. At least this forum will help perhaps by providing
>>>> us
>
>>>> with some ideas.
>
>>>>
>
>>>> Unterreiner wrote:
>
>>>> > I have an IO-360 in my Velocity with updraft cooling. The guy who
>
>>>> > built
>
>>>> > the
>
>>>> > plane went to alot of trouble to get it to cool properly in cruise,
>
>>>> > and
>
>>>> > it
>
>>>> > still needs to be modified so it will cool better during takeoff.
>
>>>> > Also,
>
>>>> > the
>
>>>> > Lycoming engines are designed to be cooled from the top down. I wish
>
>>>> > the guy
>
>>>> > who built my plane would have used the NACA plenum system. It's alot
>
>>>> > simpler, cools the engine the way it's supposed to be cooled and is
>
>>>> > less
>
>>>> > prone to develop cooling problems.
>
>>>> >
>
>>>> > Dean Unterreiner
>
>>>> > ----- Original Message -----
>
>>>> > From: <reflector-request at tvbf.org <javascript:parent.ComposeTo(> >
>
>>>> > To: <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>>>> > Sent: Saturday, February 17, 2007 5:52 PM
>
>>>> > Subject: Reflector Digest, Vol 33, Issue 47
>
>>>> >
>
>>>> >
>
>>>> >
>
>>>> >> Send Reflector mailing list submissions to
>
>>>> >> reflector at tvbf.org <javascript:parent.ComposeTo(>
>
>>>> >>
>
>>>> >> To subscribe or unsubscribe via the World Wide Web, visit
>
>>>> >> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >> or, via email, send a message with subject or body 'help' to
>
>>>> >> reflector-request at tvbf.org <javascript:parent.ComposeTo(>
>
>>>> >>
>
>>>> >> You can reach the person managing the list at
>
>>>> >> reflector-owner at tvbf.org <javascript:parent.ComposeTo(>
>
>>>> >>
>
>>>> >> When replying, please edit your Subject line so it is more specific
>
>>>> >> than "Re: Contents of Reflector digest..."
>
>>>> >>
>
>>>> >>
>
>>>> >> Today's Topics:
>
>>>> >>
>
>>>> >> 1. Re: updraft cooling (Scott Derrick)
>
>>>> >> 2. Re: updraft cooling (John Dibble)
>
>>>> >> 3. Re: updraft cooling (Douglas Holub)
>
>>>> >> 4. Re: updraft vs sidedraft vs updraft cooling (gpoole)
>
>>>> >> 5. Re: updraft cooling (Al Gietzen)
>
>>>> >>
>
>>>> >>
>
>>>> >>
> ----------------------------------------------------------------------
>
>>>> >>
>
>>>> >> Message: 1
>
>>>> >> Date: Sat, 17 Feb 2007 15:57:56 -0500 (EST)
>
>>>> >> From: "Scott Derrick" <scott at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>>> >> Message-ID: <43917.63.164.47.227.1171745876.squirrel at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>>>> >> Content-Type: text/plain;charset=iso-8859-1
>
>>>> >>
>
>>>> >> Doug,
>
>>>> >>
>
>>>> >> I had updraft on my IO360 and it worked fine. I had to run LOP in
>>>> >> the
>
>>>> >> summer(I did all the time anyway) to keep the engine cool enough.
>
>>>> >> There
>
>>>> >> were times when I stopped for gas and during the following departure
>
>>>> >> climbout I would have to level off at an intermediate altitude for
>
>>>> >> awhile
>
>>>> >> to get the oil temps back down below 230.
>
>>>> >>
>
>>>> >> Installing my 520 I conferred with Velocity(ScottB and Brendon) and
>
>>>> >> was
>
>>>> >> advised I would need to use downdraft as they had never successfully
>
>>>> >> seen
>
>>>> >> an updraft system work for the big six cylinder engines. So I did
>
>>>> >> the
>
>>>> >> conversion.
>
>>>> >>
>
>>>> >> I thought that using NACA intakes would "theoretically" be more drag
>
>>>> >> effecient ?
>
>>>> >>
>
>>>> >> Scott
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>> I can understand why Burt Rutan and Nat Puffer are proponents of
>
>>>> >>> updraft
>
>>>> >>> cooling. From an engineering point of view, it has a lot going for
>
>>>> >>> it.
>
>>>> >>> You
>
>>>> >>> need more cooling when the airplane is climbing. If the cooling
>
>>>> >>> intake is
>
>>>> >>> below the wing, the pressure is higher during a climb so you
>
>>>> >>> automatically
>
>>>> >>> get more cooling during a climb. Similarly, it would be nice if
>
>>>> >>> cooling
>
>>>> >>> was minimized during descent. The pressure is reduced under the
>>>> >>> wing
>
>>>> >>> during descent, and so there is less cooling to the engine. Also,
>
>>>> >>> you've
>
>>>> >>> got convection working with you instead of against you with an
>
>>>> >>> updraft
>
>>>> >>> system.
>
>>>> >>>
>
>>>> >>> That all adds up to more drag with down draft cooling, because the
>
>>>> >>> NACA
>
>>>> >>> scoops have to be large enough so that there is adequate cooling
>
>>>> >>> during
>
>>>> >>> climb out, when the pressure at the NACAs is at its minimum.
>
>>>> >>>
>
>>>> >>> But the down draft is a lot simpler to implement, and that's
>
>>>> >>> probably
>
>>>> >>> going to be the deciding factor for me.
>
>>>> >>>
>
>>>> >>> Doug Holub_______________________________________________
>
>>>> >>> To change your email address, visit
>
>>>> >>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>
>
>>>> >>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>> user:pw = tvbf:jamaicangoose
>
>>>> >>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>> Check old archives:
>
>>>> >>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>
>
>>>> >>
>
>>>> >> ------------------------------
>
>>>> >>
>
>>>> >> Message: 2
>
>>>> >> Date: Sat, 17 Feb 2007 15:04:56 -0600
>
>>>> >> From: John Dibble <aminetech at bluefrog.com
> <javascript:parent.ComposeTo(> >
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >> To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>>> >> Message-ID: <45D76DF8.5468770B at bluefrog.com
> <javascript:parent.ComposeTo(> >
>
>>>> >> Content-Type: text/plain; charset="us-ascii"
>
>>>> >>
>
>>>> >> I assume that updraft simply refers to the intake air coming from
>
>>>> >> below
>
>>>> >> as opposed to downdraft where the air comes from the NACAs above. I
>
>>>> >> think the way it passes the engine is the same. It would be
>
>>>> >> inefficient
>
>>>> >> to pass the air past the exhaust pipes first.
>
>>>> >>
>
>>>> >> John
>
>>>> >>
>
>>>> >> Chuck Jensen wrote:
>
>>>> >>
>
>>>> >>
>
>>>> >>> I've not seen the layout of an updraft cooling system, but does
>>>> >>> the
>
>>>> >>> air get preheated from passing by the exhaust pipes before it every
>
>>>> >>> gets to the cylinder heads? If it does, that would greatly
>>>> >>> increase
>
>>>> >>> the volume of air required because of the reduced delta T across
>>>> >>> the
>
>>>> >>> heads. By comparison the top NACAs provide clean, cool air
>>>> >>> directly
>
>>>> >>> to the CHs. Too simple--I must be missing something?
>
>>>> >>> Chuck Jensen
>
>>>> >>>
>
>>>> >>> -----Original Message-----
>
>>>> >>> From: reflector-bounces at tvbf.org <javascript:parent.ComposeTo(>
> [mailto:reflector-bounces at tvbf.org <javascript:parent.ComposeTo(> ]
>
>>>> >>> On Behalf Of John Dibble
>
>>>> >>> Sent: Saturday, February 17, 2007 2:41 PM
>
>>>> >>> To: Velocity Aircraft Owners and Builders list
>
>>>> >>> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >>>
>
>>>> >>> I think the amount of air going past the cylinders will determine
>
>>>> >>> the
>
>>>> >>> degree of cooling, so it's a matter of making the NACA or armpit
>
>>>> >>> scoop
>
>>>> >>> and ducts big enough for sufficient air.
>
>>>> >>>
>
>>>> >>> John
>
>>>> >>>
>
>>>> >>> Ron Brown wrote:
>
>>>> >>>
>
>>>> >>>
>
>>>> >>>> And, the downdraft NACA cooling for some unexplainable reason,
>>>> >>>> runs
>
>>>> >>>> about 40 degrees cooler than the updraft cooling. Mark Machado
>
>>>> >>>> converted what is now the factory trainer from updraft to
>>>> >>>> downdraft
>
>>>> >>>> and says the heads ran 30-40 degrees cooler. My 173 Elite RG runs
>
>>>> >>>> 360-370 max on a long climb out and 320-340 degrees during a 2600
>
>>>> >>>> rpm/155 kt cruise. I highly recommend the NACA cooling system.
>
>>>> >>>>
>
>>>> >>> ----------------------------------------------------------------
>
>>>> >>> _______________________________________________
>
>>>> >>> To change your email address, visit
>
>>>> >>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>
>
>>>> >>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>> user:pw = tvbf:jamaicangoose
>
>>>> >>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>> Check old archives:
>
>>>> >>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>
>
>>>> >>>
>
>>>> >> -------------- next part --------------
>
>>>> >> An HTML attachment was scrubbed...
>
>>>> >> URL:
>
>>>> >>
> http://www.tvbf.org/mailman/private/reflector/attachments/20070217/daaba585/
> attachment.htm
>
>>>> >>
>
>>>> >> ------------------------------
>
>>>> >>
>
>>>> >> Message: 3
>
>>>> >> Date: Sat, 17 Feb 2007 16:13:01 -0600
>
>>>> >> From: "Douglas Holub" <doug.holub at tx.rr.com
> <javascript:parent.ComposeTo(> >
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>>> >> Message-ID: <007e01c752e0$ca67f130$6a01a8c0 at Workshop>
>
>>>> >> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>
>>>> >> reply-type=original
>
>>>> >>
>
>>>> >> "I thought that using NACA intakes would 'theoretically' be more
>>>> >> drag
>
>>>> >> effecient ?"
>
>>>> >> -------------------------------------------------------------------
>
>>>> >> I was just comparing updraft to downdraft. It looks like I could put
>
>>>> >> one
>
>>>> >> big
>
>>>> >> NACA underneath the rear seat. I was thinking of using that spot for
>
>>>> >> ram
>
>>>> >> air, though.
>
>>>> >>
>
>>>> >> I'm a little confused about the benefits of a NACA scoop. I need to
>
>>>> >> read
>
>>>> >> up
>
>>>> >> on them some more. I think that if the cowl lip were extended up a
>
>>>> >> little
>
>>>> >> to
>
>>>> >> catch the air it might be more efficient than the NACA scoops. But
>
>>>> >> even
>
>>>> >> if
>
>>>> >> it were more efficient, you would be making it a little harder for
>
>>>> >> air
>
>>>> >> to
>
>>>> >> flow to the propeller because the cowl would be getting a little
>
>>>> >> taller.
>
>>>> >> But
>
>>>> >> then, you lose some head room in the back seats with the NACAs.
>
>>>> >> Decisions,
>
>>>> >> decisions.
>
>>>> >>
>
>>>> >> Doug Holub
>
>>>> >>
>
>>>> >> ----- Original Message -----
>
>>>> >> From: "Scott Derrick" <scott at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>>>> >> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>>> >> Sent: Saturday, February 17, 2007 2:57 PM
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>> Doug,
>
>>>> >>>
>
>>>> >>> I had updraft on my IO360 and it worked fine. I had to run LOP in
>
>>>> >>> the
>
>>>> >>> summer(I did all the time anyway) to keep the engine cool enough.
>
>>>> >>> There
>
>>>> >>> were times when I stopped for gas and during the following
>>>> >>> departure
>
>>>> >>> climbout I would have to level off at an intermediate altitude for
>
>>>> >>> awhile
>
>>>> >>> to get the oil temps back down below 230.
>
>>>> >>>
>
>>>> >>> Installing my 520 I conferred with Velocity(ScottB and Brendon) and
>
>>>> >>> was
>
>>>> >>> advised I would need to use downdraft as they had never
>>>> >>> successfully
>
>>>> >>> seen
>
>>>> >>> an updraft system work for the big six cylinder engines. So I did
>
>>>> >>> the
>
>>>> >>> conversion.
>
>>>> >>>
>
>>>> >>> I thought that using NACA intakes would "theoretically" be more
>>>> >>> drag
>
>>>> >>> effecient ?
>
>>>> >>>
>
>>>> >>> Scott
>
>>>> >>>
>
>>>> >>>
>
>>>> >>>
>
>>>> >>>> I can understand why Burt Rutan and Nat Puffer are proponents of
>
>>>> >>>> updraft
>
>>>> >>>> cooling. From an engineering point of view, it has a lot going for
>
>>>> >>>> it.
>
>>>> >>>> You
>
>>>> >>>> need more cooling when the airplane is climbing. If the cooling
>
>>>> >>>> intake
>
>>>> >>>> is
>
>>>> >>>> below the wing, the pressure is higher during a climb so you
>
>>>> >>>> automatically
>
>>>> >>>> get more cooling during a climb. Similarly, it would be nice if
>
>>>> >>>> cooling
>
>>>> >>>> was minimized during descent. The pressure is reduced under the
>
>>>> >>>> wing
>
>>>> >>>> during descent, and so there is less cooling to the engine. Also,
>
>>>> >>>> you've
>
>>>> >>>> got convection working with you instead of against you with an
>
>>>> >>>> updraft
>
>>>> >>>> system.
>
>>>> >>>>
>
>>>> >>>> That all adds up to more drag with down draft cooling, because the
>
>>>> >>>> NACA
>
>>>> >>>> scoops have to be large enough so that there is adequate cooling
>
>>>> >>>> during
>
>>>> >>>> climb out, when the pressure at the NACAs is at its minimum.
>
>>>> >>>>
>
>>>> >>>> But the down draft is a lot simpler to implement, and that's
>
>>>> >>>> probably
>
>>>> >>>> going to be the deciding factor for me.
>
>>>> >>>>
>
>>>> >>>> Doug Holub_______________________________________________
>
>>>> >>>> To change your email address, visit
>
>>>> >>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>>
>
>>>> >>>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>>> user:pw = tvbf:jamaicangoose
>
>>>> >>>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>>> Check old archives:
>
>>>> >>>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>>
>
>>>> >>> _______________________________________________
>
>>>> >>> To change your email address, visit
>
>>>> >>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>
>
>>>> >>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>> user:pw = tvbf:jamaicangoose
>
>>>> >>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>> Check old archives:
>
>>>> >>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>
>
>>>> >>>
>
>>>> >>
>
>>>> >>
>
>>>> >> ------------------------------
>
>>>> >>
>
>>>> >> Message: 4
>
>>>> >> Date: Sun, 18 Feb 2007 09:29:29 +1100
>
>>>> >> From: "gpoole" <gpoole at zeta.org.au <javascript:parent.ComposeTo(> >
>
>>>> >> Subject: Re: REFLECTOR: updraft vs sidedraft vs updraft cooling
>
>>>> >> To: "'Velocity Aircraft Owners and Builders list'"
>
>>>> >> <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>>>> >> Message-ID: <00b801c752e3$1725de40$4deb64cb at gregb97b7132b4>
>
>>>> >> Content-Type: text/plain; charset="windows-1250"
>
>>>> >>
>
>>>> >> I have been making the same deliberations as Doug for quite some
>
>>>> >> time.
>
>>>> >> There are compromises with every option ..sigh! Scoops vs NACA
>
>>>> >> ducts...
>
>>>> >>
>
>>>> >> If pinching air before the prop with a scoop on the belly is
>
>>>> >> considered to
>
>>>> >> affect prop efficiency then perhaps (surely?) Al G's & several
>
>>>> >> other's
>
>>>> >> approach of putting radiators in the wing is the way to go. I like
>
>>>> >> the
>
>>>> >> idea
>
>>>> >> of being able to tailor the amount of air to the radiators to
>>>> >> balance
>
>>>> >> the
>
>>>> >> compromise between drag and amount of cooling required by having
>
>>>> >> variable
>
>>>> >> inlets. Only problem is that the air needs to do several sharp turns
>
>>>> >> to
>
>>>> >> get
>
>>>> >> to the cylinder heads....which would should slow it down
>
>>>> >> considerably....
>
>>>> >>
>
>>>> >> Would be interested in this thread continuing to see what others
>
>>>> >> think....
>
>>>> >>
>
>>>> >> Greg in Sydney.
>
>>>> >>
>
>>>> >> gregpoole at saaachapter11.com <javascript:parent.ComposeTo(>
>
>>>> >>
>
>>>> >>
>
>>>> >> -----Original Message-----
>
>>>> >> From: reflector-bounces at tvbf.org <javascript:parent.ComposeTo(>
> [mailto:reflector-bounces at tvbf.org <javascript:parent.ComposeTo(> ]
>
>>>> >> On
>
>>>> >> Behalf Of Douglas Holub
>
>>>> >> Sent: Sunday, 18 February 2007 9:13 AM
>
>>>> >> To: Velocity Aircraft Owners and Builders list
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >>
>
>>>> >> "I thought that using NACA intakes would 'theoretically' be more
>>>> >> drag
>
>>>> >> effecient ?"
>
>>>> >> -------------------------------------------------------------------
>
>>>> >> I was just comparing updraft to downdraft. It looks like I could put
>
>>>> >> one
>
>>>> >> big
>
>>>> >>
>
>>>> >> NACA underneath the rear seat. I was thinking of using that spot for
>
>>>> >> ram
>
>>>> >> air, though.
>
>>>> >>
>
>>>> >> I'm a little confused about the benefits of a NACA scoop. I need to
>
>>>> >> read
>
>>>> >> up
>
>>>> >>
>
>>>> >> on them some more. I think that if the cowl lip were extended up a
>
>>>> >> little
>
>>>> >> to
>
>>>> >>
>
>>>> >> catch the air it might be more efficient than the NACA scoops. But
>
>>>> >> even
>
>>>> >> if
>
>>>> >> it were more efficient, you would be making it a little harder for
>
>>>> >> air
>
>>>> >> to
>
>>>> >> flow to the propeller because the cowl would be getting a little
>
>>>> >> taller.
>
>>>> >> But
>
>>>> >>
>
>>>> >> then, you lose some head room in the back seats with the NACAs.
>
>>>> >> Decisions,
>
>>>> >> decisions.
>
>>>> >>
>
>>>> >> Doug Holub
>
>>>> >>
>
>>>> >> ----- Original Message -----
>
>>>> >> From: "Scott Derrick" <scott at tnstaafl.net
> <javascript:parent.ComposeTo(> >
>
>>>> >> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>>> >> Sent: Saturday, February 17, 2007 2:57 PM
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>> Doug,
>
>>>> >>>
>
>>>> >>> I had updraft on my IO360 and it worked fine. I had to run LOP in
>
>>>> >>> the
>
>>>> >>> summer(I did all the time anyway) to keep the engine cool enough.
>
>>>> >>> There
>
>>>> >>> were times when I stopped for gas and during the following
>>>> >>> departure
>
>>>> >>> climbout I would have to level off at an intermediate altitude for
>
>>>> >>> awhile
>
>>>> >>> to get the oil temps back down below 230.
>
>>>> >>>
>
>>>> >>> Installing my 520 I conferred with Velocity(ScottB and Brendon) and
>
>>>> >>> was
>
>>>> >>> advised I would need to use downdraft as they had never
>>>> >>> successfully
>
>>>> >>> seen
>
>>>> >>> an updraft system work for the big six cylinder engines. So I did
>
>>>> >>> the
>
>>>> >>> conversion.
>
>>>> >>>
>
>>>> >>> I thought that using NACA intakes would "theoretically" be more
>>>> >>> drag
>
>>>> >>> effecient ?
>
>>>> >>>
>
>>>> >>> Scott
>
>>>> >>>
>
>>>> >>>
>
>>>> >>>
>
>>>> >>>> I can understand why Burt Rutan and Nat Puffer are proponents of
>
>>>> >>>> updraft
>
>>>> >>>> cooling. From an engineering point of view, it has a lot going for
>
>>>> >>>> it.
>
>>>> >>>> You
>
>>>> >>>> need more cooling when the airplane is climbing. If the cooling
>
>>>> >>>> intake
>
>>>> >>>> is
>
>>>> >>>> below the wing, the pressure is higher during a climb so you
>
>>>> >>>> automatically
>
>>>> >>>> get more cooling during a climb. Similarly, it would be nice if
>
>>>> >>>> cooling
>
>>>> >>>> was minimized during descent. The pressure is reduced under the
>
>>>> >>>> wing
>
>>>> >>>> during descent, and so there is less cooling to the engine. Also,
>
>>>> >>>> you've
>
>>>> >>>> got convection working with you instead of against you with an
>
>>>> >>>> updraft
>
>>>> >>>> system.
>
>>>> >>>>
>
>>>> >>>> That all adds up to more drag with down draft cooling, because the
>
>>>> >>>> NACA
>
>>>> >>>> scoops have to be large enough so that there is adequate cooling
>
>>>> >>>> during
>
>>>> >>>> climb out, when the pressure at the NACAs is at its minimum.
>
>>>> >>>>
>
>>>> >>>> But the down draft is a lot simpler to implement, and that's
>
>>>> >>>> probably
>
>>>> >>>> going to be the deciding factor for me.
>
>>>> >>>>
>
>>>> >>>> Doug Holub_______________________________________________
>
>>>> >>>> To change your email address, visit
>
>>>> >>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>>
>
>>>> >>>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>>> user:pw = tvbf:jamaicangoose
>
>>>> >>>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>>> Check old archives:
>
>>>> >>>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>>
>
>>>> >>> _______________________________________________
>
>>>> >>> To change your email address, visit
>
>>>> >>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>>
>
>>>> >>> Visit the gallery! www.tvbf.org/gallery
>
>>>> >>> user:pw = tvbf:jamaicangoose
>
>>>> >>> Check new archives: www.tvbf.org/pipermail
>
>>>> >>> Check old archives:
>
>>>> >>> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>>
>
>>>> >>>
>
>>>> >> _______________________________________________
>
>>>> >> To change your email address, visit
>
>>>> >> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >>
>
>>>> >> Visit the gallery! www.tvbf.org/gallery
>
>>>> >> user:pw = tvbf:jamaicangoose
>
>>>> >> Check new archives: www.tvbf.org/pipermail
>
>>>> >> Check old archives:
>
>>>> >> http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >>
>
>>>> >> --
>
>>>> >> No virus found in this incoming message.
>
>>>> >> Checked by AVG Free Edition.
>
>>>> >> Version: 7.1.412 / Virus Database: 268.18.1/690 - Release Date:
>
>>>> >> 16/02/2007
>
>>>> >>
>
>>>> >>
>
>>>> >> --
>
>>>> >> No virus found in this outgoing message.
>
>>>> >> Checked by AVG Free Edition.
>
>>>> >> Version: 7.1.412 / Virus Database: 268.18.1/690 - Release Date:
>
>>>> >> 16/02/2007
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> ------------------------------
>
>>>> >>
>
>>>> >> Message: 5
>
>>>> >> Date: Sat, 17 Feb 2007 14:52:30 -0800
>
>>>> >> From: "Al Gietzen" <ALVentures at cox.net
>>>> >> <javascript:parent.ComposeTo(>
>>
>
>>>> >> Subject: Re: REFLECTOR: updraft cooling
>
>>>> >> To: "'Velocity Aircraft Owners and Builders list'"
>
>>>> >> <reflector at tvbf.org <javascript:parent.ComposeTo(> >
>
>>>> >> Message-ID: <000001c752e6$4ecd94c0$6400a8c0 at BigAl>
>
>>>> >> Content-Type: text/plain; charset="us-ascii"
>
>>>> >>
>
>>>> >> Subject: REFLECTOR: updraft cooling
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> I can understand why Burt Rutan and Nat Puffer are proponents of
>
>>>> >> updraft
>
>>>> >> cooling. From an engineering point of view, it has a lot going for
>
>>>> >> it.
>
>>>> >> You
>
>>>> >> need more cooling when the airplane is climbing. If the cooling
>
>>>> >> intake
>
>>>> >> is
>
>>>> >> below the wing, the pressure is higher during a climb so you
>
>>>> >> automatically
>
>>>> >> get more cooling during a climb. Similarly, it would be nice if
>
>>>> >> cooling
>
>>>> >> was
>
>>>> >> minimized during descent. The pressure is reduced under the wing
>
>>>> >> during
>
>>>> >> descent, and so there is less cooling to the engine. Also, you've
>>>> >> got
>
>>>> >> convection working with you instead of against you with an updraft
>
>>>> >> system.
>
>>>> >>
>
>>>> >> Doug;
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> I'd think that both climbing and descending are high AOA, and would
>
>>>> >> have
>
>>>> >> similar air pressure under the wing; and given the strake
>
>>>> >> configuration,
>
>>>> >> it
>
>>>> >> is not clear that there is increased pressure during climb. I also
>
>>>> >> think
>
>>>> >> that the main reason for difficulties with the stock armpit scoops
>
>>>> >> and
>
>>>> >> updraft is they are poorly designed scoops. Need to have ever
>
>>>> >> increasing
>
>>>> >> x-section after the entrance, and possilby placing them a bit
>>>> >> further
>
>>>> >> outboard from the strake/fuselage intersection would be helpful.
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> I have an 'armpit' scoop for my radiator which is very effective.
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> But the down draft is a lot simpler to implement, and that's
>>>> >> probably
>
>>>> >> going
>
>>>> >> to be the deciding factor for me.
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> And since it seems to work well, why not? The amount of natural
>
>>>> >> convection
>
>>>> >> driving force is likely overcome by a few knots of forward speed.
>
>>>> >>
>
>>>> >> Al
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >>
>
>>>> >> Doug Holub
>
>>>> >>
>
>>>> >> -------------- next part --------------
>
>>>> >> An HTML attachment was scrubbed...
>
>>>> >> URL:
>
>>>> >>
> http://www.tvbf.org/mailman/private/reflector/attachments/20070217/bff4b314/
> attachment.html
>
>>>> >>
>
>>>> >> ------------------------------
>
>>>> >>
>
>>>> >> _______________________________________________
>
>>>> >> Visit the gallery! tvbf:jamaicangoose
>
>>>> >>
>
>>>> >> End of Reflector Digest, Vol 33, Issue 47
>
>>>> >> *****************************************
>
>>>> >>
>
>>>> >
>
>>>> > _______________________________________________
>
>>>> > To change your email address, visit
>
>>>> > http://www.tvbf.org/mailman/listinfo/reflector
>
>>>> >
>
>>>> > Visit the gallery! www.tvbf.org/gallery
>
>>>> > user:pw = tvbf:jamaicangoose
>
>>>> > Check new archives: www.tvbf.org/pipermail
>
>>>> > Check old archives:
>
>>>> > http://www.tvbf.org/archives/velocity/maillist.html
>
>>>> >
>
>>>> >
>
>>>> >
>
>>>>
>
>>>> --
>
>>>> Dave Philipsen
>
>>>> Velocity STD-FG
>
>>>> N83DP
>
>>>>
>
>>>> _______________________________________________
>
>>>> To change your email address, visit
>
>>>> http://www.tvbf.org/mailman/listinfo/reflector
>
>>>>
>
>>>> Visit the gallery! www.tvbf.org/gallery
>
>>>> user:pw = tvbf:jamaicangoose
>
>>>> Check new archives: www.tvbf.org/pipermail
>
>>>> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html
>
>>>
>
>>>
>
>>>
>
>>> ------------------------------
>
>>>
>
>>> Message: 2
>
>>> Date: Sun, 18 Feb 2007 10:29:52 -0600
>
>>> From: "John Tvedte" <johnt at comp-sol.com <javascript:parent.ComposeTo(> >
>
>>> Subject: Re: REFLECTOR: CBs and fuses
>
>>> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org
> <javascript:parent.ComposeTo(> >
>
>>> Message-ID:
>
>>> <182DCED417B03E45BDB40B10169D1D020A95EF at exchange-2003.comp-sol.com
> <javascript:parent.ComposeTo(> >
>
>>> Content-Type: text/plain; charset="iso-8859-1"
>
>>>
>
>>> Personally I think CB's are the proper choice - I think it makes more
>
>>> sense for the Pilot to choose to reset or NOT reset a circuit.
>
>>>
>
>>> John
>
>>>
>
>>> ________________________________
>
>>>
>
>>> From: reflector-bounces at tvbf.org <javascript:parent.ComposeTo(> on
> behalf of John Overman
>
>>> Sent: Sun 2/18/2007 10:16 AM
>
>>> To: bbradburry at allvantage.com <javascript:parent.ComposeTo(> ;
> reflector at tvbf.org <javascript:parent.ComposeTo(>
>
>>> Subject: Re: REFLECTOR: CBs and fuses
>
>>>
>
>>>
>
>>>
>
>>> Hi Bill;
>
>>> I ordered them from Mouser Electronics, they are
>
>>> also available from Digi-Key and Allied Electronics
>
>>> Supply. They are called PTC resettable fuses and are
>
>>> manufactured by Bournes, Raychem Tyco, and Little
>
>>> Fuse. There is a good explaination about how the work
>
>>> on Raychem and most of the other's websites. Here's a
>
>>> rough explaination of how the work. They contain
>
>>> "tracks" of carbon which makes the connection. When
>
>>> they get hot the tracks "flow out" so they are no
>
>>> longer conductive thus breaking the circuit. If the
>
>>> device causing the overload is shut off, the fuse
>
>>> quickly cools and the tracks reform thus "resetting"
>
>>> the fuse. If the device is not turned off the circuit
>
>>> remains open. I will install them in "Proto-Board" and
>
>>> hard wire them to terminal blocks (Buchanan terminal
>
>>> blocks) also from Mouser 12 terminals 2.5"wide for
>
>>> $6.03, mounted along the edge of the board.
>
>>> I ordered the RayChem fuses because they have them
>
>>> rated up to 14 amps and they can be paralleled which
>
>>> would give you a 28 Amp fuse. 0.5 amp fuses are $0.54
>
>>> ea. and 14amp fuses are $1.34 ea.
>
>>> They are reported to trip faster, and more
>
>>> accurately, than a breaker and cool to reset faster.
>
>>> Greg Richter (Blue Mountain Avionics) uses them in his
>
>>> "Power Board".
>
>>> I hope this isn't more information than you wanted,
>
>>> and that it helps.
>
>>> John Overman
>
>>> Velocity RG N711VE (reserved)
>
>>>
>
>>>
>
>>> --- Bill Bradburry <bbradburry at allvantage.com
> <javascript:parent.ComposeTo(> > wrote:
>
>>>
>
>>>> Hi John.
>
>>>> Where will you get the resettable fuses? Several
>
>>>> folks on the list have
>
>>>> suggested that I install CBs in my flight critical
>
>>>> areas. I am thinking
>
>>>> that the resettable fuses might solve the problem...
>
>>>> What do you think?
>
>>>>
>
>>>> Bill Bradburry (Lancair Legacy FG / Renesis)
>
>>>>
>
>>>>
>
>>>> Subject:
>
>>>> Re: [FlyRotary] CBs and fuses
>
>>>> From:
>
>>>> John Overman <mooneydryver at yahoo.com <javascript:parent.ComposeTo(> >
>
>>>> Date:
>
>>>> Sat, 17 Feb 2007 16:15:29 -0800 (PST)
>
>>>>
>
>>>> Al or anyone, speaking of fuses, I'm about to order
>
>>>> PTC resettable fuses in my Velocity, and haven't
>
>>>> been
>
>>>> able to find any load values for the stock mazda
>
>>>> coils, the fuel injectors, the EC2 or the EM2, Al as
>
>>>> I
>
>>>> recall you are using LS1 coils not Mazda but I
>
>>>> haven't
>
>>>> come up with anything. I even looked in the RX7
>
>>>> manual
>
>>>> to see what size fuse Mazda used. It just says the
>
>>>> fuses are listed under the cap.
>
>>>> John Overman
>
>>>> Velocity RG N711VE
>
>>>> (reserved)
>
>>>>
>
>>>
>
>>>
>
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>>> End of Reflector Digest, Vol 33, Issue 52
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>>> *****************************************
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>>
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>>
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>>
>
>> ------------------------------
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>>
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>> _______________________________________________
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>> Visit the gallery! tvbf:jamaicangoose
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>> End of Reflector Digest, Vol 33, Issue 61
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