Intake plenum

[Neal Fulco]

I'm thinking about making a carb. heat plenum for my plane out of
fiberglass ( epoxy.) I had done it once for my Quickie many years
ago because that's what what the plans said to do. But that was a
very small plenum. Due to space constraints, it would be very easy to
make it out of fiberglass for my new project ( 120 h.p.) but I'm
wondering if the carb heat would be too hot for the fiberglass. I
will make it out of aluminum if I have to, but it would be harder to
do. Do you think the fiberglass would work? Thanks

Neal

[[email protected]]

On Sat, 3 Apr 2010 12:52:03 -0700 (PDT), Neal Fulco >
wrote:

>I'm thinking about making a carb. heat plenum for my plane out of
>fiberglass ( epoxy.) I had done it once for my Quickie many years
>ago because that's what what the plans said to do. But that was a
>very small plenum. Due to space constraints, it would be very easy to
>make it out of fiberglass for my new project ( 120 h.p.) but I'm
>wondering if the carb heat would be too hot for the fiberglass. I
>will make it out of aluminum if I have to, but it would be harder to
>do. Do you think the fiberglass would work? Thanks
>
>Neal
Nope. Fiberglass (unless you are getting ito really exotic resins)
won't handle the heat.

[cavelamb[_3_]]

On 4/3/2010 8:28 PM, wrote:
> On Sat, 3 Apr 2010 12:52:03 -0700 (PDT), Neal >
> wrote:
>
>> I'm thinking about making a carb. heat plenum for my plane out of
>> fiberglass ( epoxy.) I had done it once for my Quickie many years
>> ago because that's what what the plans said to do. But that was a
>> very small plenum. Due to space constraints, it would be very easy to
>> make it out of fiberglass for my new project ( 120 h.p.) but I'm
>> wondering if the carb heat would be too hot for the fiberglass. I
>> will make it out of aluminum if I have to, but it would be harder to
>> do. Do you think the fiberglass would work? Thanks
>>
>> Neal
> Nope. Fiberglass (unless you are getting ito really exotic resins)
> won't handle the heat.


90 degrees above ambient?

200 max?

--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/

[[email protected]]

On Sat, 03 Apr 2010 21:54:40 -0500, cavelamb <""cavelamb\"@ X
earthlink.net"> wrote:

>On 4/3/2010 8:28 PM, wrote:
>> On Sat, 3 Apr 2010 12:52:03 -0700 (PDT), Neal >
>> wrote:
>>
>>> I'm thinking about making a carb. heat plenum for my plane out of
>>> fiberglass ( epoxy.) I had done it once for my Quickie many years
>>> ago because that's what what the plans said to do. But that was a
>>> very small plenum. Due to space constraints, it would be very easy to
>>> make it out of fiberglass for my new project ( 120 h.p.) but I'm
>>> wondering if the carb heat would be too hot for the fiberglass. I
>>> will make it out of aluminum if I have to, but it would be harder to
>>> do. Do you think the fiberglass would work? Thanks
>>>
>>> Neal
>> Nope. Fiberglass (unless you are getting ito really exotic resins)
>> won't handle the heat.
>
>
>90 degrees above ambient?
>
>200 max?
That is the minimum required
Can often be a lot hotter than that. Only isophthalic resin rated for
210F and Vynylester rated at 241F would even be close. None of the
common epoxies are rated for that temperature. You would need a
novolac based epoxy (special high temperature epoxy resin)

[et]

On Apr 3, 12:52*pm, Neal Fulco > wrote:
> I'm thinking about making a carb. heat plenum for my plane out of
> fiberglass ( epoxy.) * I had done it once for my Quickie many years
> ago because that's what what the plans said to do. *But that was a
> very small plenum. *Due to space constraints, it would be very easy to
> make it out of fiberglass for my new project ( 120 h.p.) but I'm
> wondering if the carb heat would be too hot for the fiberglass. *I
> will make it out of aluminum if I have to, but it would be harder to
> do. *Do you think the fiberglass would work? *Thanks
>
> Neal

On my Glasair, I have a composite plenum on the intake side of the
carb with a flapper valve to direct air. The plenum is actually part
of the cowl with a rubber gasket next to the carb. Don't know what
was used to make the part, but it's attached to the cowl with
vinylester. Seems to work OK.

Ed

[Ernest Christley]

wrote:

>> 90 degrees above ambient?
>>
>> 200 max?
> That is the minimum required
> Can often be a lot hotter than that. Only isophthalic resin rated for
> 210F and Vynylester rated at 241F would even be close. None of the
> common epoxies are rated for that temperature. You would need a
> novolac based epoxy (special high temperature epoxy resin)

Thin some JBWeld. Squish it into the glass between sheets of cellophane
with a large socket or piece of pipe.

[[email protected]]

On Wed, 07 Apr 2010 19:56:31 -0400, Ernest Christley
> wrote:

wrote:
>
>>> 90 degrees above ambient?
>>>
>>> 200 max?
>> That is the minimum required
>> Can often be a lot hotter than that. Only isophthalic resin rated for
>> 210F and Vynylester rated at 241F would even be close. None of the
>> common epoxies are rated for that temperature. You would need a
>> novolac based epoxy (special high temperature epoxy resin)
>
>Thin some JBWeld. Squish it into the glass between sheets of cellophane
>with a large socket or piece of pipe.

A BADGE Resin (Bisphenol A DiGlycidyl Ether) resin is another one of
the special high temperature epoxy resins.

Good to about 500

[cavelamb[_3_]]

On 4/7/2010 10:04 PM, wrote:
> On Wed, 07 Apr 2010 19:56:31 -0400, Ernest Christley
> > wrote:
>
>> wrote:
>>
>>>> 90 degrees above ambient?
>>>>
>>>> 200 max?
>>> That is the minimum required
>>> Can often be a lot hotter than that. Only isophthalic resin rated for
>>> 210F and Vynylester rated at 241F would even be close. None of the
>>> common epoxies are rated for that temperature. You would need a
>>> novolac based epoxy (special high temperature epoxy resin)
>>
>> Thin some JBWeld. Squish it into the glass between sheets of cellophane
>> with a large socket or piece of pipe.
>
> A BADGE Resin (Bisphenol A DiGlycidyl Ether) resin is another one of
> the special high temperature epoxy resins.
>
> Good to about 500

Come on, guys!
How hot do you think the intake air can be and still have the motor run???

--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/

[[email protected]]

On Wed, 07 Apr 2010 22:19:44 -0500, cavelamb <""cavelamb\"@ X
earthlink.net"> wrote:

>On 4/7/2010 10:04 PM, wrote:
>> On Wed, 07 Apr 2010 19:56:31 -0400, Ernest Christley
>> > wrote:
>>
>>> wrote:
>>>
>>>>> 90 degrees above ambient?
>>>>>
>>>>> 200 max?
>>>> That is the minimum required
>>>> Can often be a lot hotter than that. Only isophthalic resin rated for
>>>> 210F and Vynylester rated at 241F would even be close. None of the
>>>> common epoxies are rated for that temperature. You would need a
>>>> novolac based epoxy (special high temperature epoxy resin)
>>>
>>> Thin some JBWeld. Squish it into the glass between sheets of cellophane
>>> with a large socket or piece of pipe.
>>
>> A BADGE Resin (Bisphenol A DiGlycidyl Ether) resin is another one of
>> the special high temperature epoxy resins.
>>
>> Good to about 500
>
>Come on, guys!
>How hot do you think the intake air can be and still have the motor run???
I forgot to say JB Weld is a BADGE resin- which is why I mentioned
it.

[Peter Dohm]

"cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message
m...
> On 4/7/2010 10:04 PM, wrote:
>> On Wed, 07 Apr 2010 19:56:31 -0400, Ernest Christley
>> > wrote:
>>
>>> wrote:
>>>
>>>>> 90 degrees above ambient?
>>>>>
>>>>> 200 max?
>>>> That is the minimum required
>>>> Can often be a lot hotter than that. Only isophthalic resin rated for
>>>> 210F and Vynylester rated at 241F would even be close. None of the
>>>> common epoxies are rated for that temperature. You would need a
>>>> novolac based epoxy (special high temperature epoxy resin)
>>>
>>> Thin some JBWeld. Squish it into the glass between sheets of cellophane
>>> with a large socket or piece of pipe.
>>
>> A BADGE Resin (Bisphenol A DiGlycidyl Ether) resin is another one of
>> the special high temperature epoxy resins.
>>
>> Good to about 500
>
> Come on, guys!
> How hot do you think the intake air can be and still have the motor run???
>
> --
>
> Richard Lamb
> http://www.home.earthlink.net/~cavelamb/
>
>
I was really wondering about that as well--and also doubting the required
strength...

Peter

[Ron Wanttaja[_2_]]

Peter Dohm wrote:
> "cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message

>> Come on, guys!
>> How hot do you think the intake air can be and still have the motor run???
>>
> I was really wondering about that as well--and also doubting the required
> strength...

The air doesn't stick around long enough to GET hot...it's moving past
in a hurry. However, the plenum is in direct mechanical contact with
the hot parts of the engine. The airflow will help cool it, but
there're still parts in direct contact.

Ron Wanttaja

[et]

On Apr 10, 6:26*pm, Ron Wanttaja > wrote:
> Peter Dohm wrote:
> > "cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message
> >> Come on, guys!
> >> How hot do you think the intake air can be and still have the motor run???
>
> > I was really wondering about that as well--and also doubting the required
> > strength...
>
> The air doesn't stick around long enough to GET hot...it's moving past
> in a hurry. *However, the plenum is in direct mechanical contact with
> the hot parts of the engine. *The airflow will help cool it, but
> there're still parts in direct contact.
>
> Ron Wanttaja

We're not talking about a composite heat muff? Are we? Surely,
we're talking about the part that directs air into the carb?

Ed

[Neal Fulco]

On Apr 11, 9:40*am, et > wrote:
> On Apr 10, 6:26*pm, Ron Wanttaja > wrote:
>
> > Peter Dohm wrote:
> > > "cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message
> > >> Come on, guys!
> > >> How hot do you think the intake air can be and still have the motor run???
>
> > > I was really wondering about that as well--and also doubting the required
> > > strength...
>
> > The air doesn't stick around long enough to GET hot...it's moving past
> > in a hurry. *However, the plenum is in direct mechanical contact with
> > the hot parts of the engine. *The airflow will help cool it, but
> > there're still parts in direct contact.
>
> > Ron Wanttaja
>
> We're not talking about a composite heat muff? * Are we? * Surely,
> we're talking about the part that directs air into the carb?
>
> Ed

Right, we're talking about the plenum itself, not the muff. The only
part that will contact anything on the engine will be the flange that
attaches to the carb. It will be a few inches away from the exhaust
manifold so that is a concern also. I even thought of making the
basic structure out of thin aluminum, wrapping that with fiberfrax,
(the thin stuff you usually sandwich between the stainless and plywood
on a composite construction) and then glassing over that. Sounds
labor intensive, but seeing the work needed for fitting, riveting, etc
that is needed for an all aluminum structure, it's really not that
more involved.

Neal

[et]

On Apr 12, 9:21*am, Neal Fulco > wrote:
> On Apr 11, 9:40*am, et > wrote:
>
>
>
>
>
> > On Apr 10, 6:26*pm, Ron Wanttaja > wrote:
>
> > > Peter Dohm wrote:
> > > > "cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message
> > > >> Come on, guys!
> > > >> How hot do you think the intake air can be and still have the motor run???
>
> > > > I was really wondering about that as well--and also doubting the required
> > > > strength...
>
> > > The air doesn't stick around long enough to GET hot...it's moving past
> > > in a hurry. *However, the plenum is in direct mechanical contact with
> > > the hot parts of the engine. *The airflow will help cool it, but
> > > there're still parts in direct contact.
>
> > > Ron Wanttaja
>
> > We're not talking about a composite heat muff? * Are we? * Surely,
> > we're talking about the part that directs air into the carb?
>
> > Ed
>
> Right, we're talking about the plenum itself, not the muff. *The only
> part that will contact anything on the engine will be the flange that
> attaches to the carb. *It will be a few inches away from the exhaust
> manifold so that is a concern also. *I even thought of making the
> basic structure out of thin aluminum, wrapping that with fiberfrax,
> (the thin stuff you usually sandwich between the stainless and plywood
> on a composite construction) and then glassing over that. * Sounds
> labor intensive, but seeing the work needed for fitting, riveting, etc
> that is needed for an all aluminum structure, it's really not that
> more involved.
>
> Neal- Hide quoted text -
>
> - Show quoted text -

Neal

If you have room, you might consider a heat shield attached to the
exhaust pipe. I ran the exhaust out the side with the coolant air,
so my lower cowl is relatively cool. No exhaust pipes to heat things
up.

Ed

[Ernest Christley]

Neal Fulco wrote:
> On Apr 11, 9:40 am, et > wrote:
>> On Apr 10, 6:26 pm, Ron Wanttaja > wrote:
>>
>>> Peter Dohm wrote:
>>>> "cavelamb" <""cavelamb\"@ X earthlink.net"> wrote in message
>>>>> Come on, guys!
>>>>> How hot do you think the intake air can be and still have the motor run???
>>>> I was really wondering about that as well--and also doubting the required
>>>> strength...
>>> The air doesn't stick around long enough to GET hot...it's moving past
>>> in a hurry. However, the plenum is in direct mechanical contact with
>>> the hot parts of the engine. The airflow will help cool it, but
>>> there're still parts in direct contact.
>>> Ron Wanttaja
>> We're not talking about a composite heat muff? Are we? Surely,
>> we're talking about the part that directs air into the carb?
>>
>> Ed
>
> Right, we're talking about the plenum itself, not the muff. The only
> part that will contact anything on the engine will be the flange that
> attaches to the carb. It will be a few inches away from the exhaust
> manifold so that is a concern also. I even thought of making the
> basic structure out of thin aluminum, wrapping that with fiberfrax,
> (the thin stuff you usually sandwich between the stainless and plywood
> on a composite construction) and then glassing over that. Sounds
> labor intensive, but seeing the work needed for fitting, riveting, etc
> that is needed for an all aluminum structure, it's really not that
> more involved.
>
> Neal

The most severe temperature will be right after shutdown, when the
engine is still hot but there is no longer any cooling air flowing.