More heat transfer stuff. was:What about the port?

[Scirocco-Al" <scirocco-Al@insight.rr.com (Scirocco-Al)]

I had a problem at work just last year where we were designing heat stakers
to stake parts into a plastic bottle.  One of the things we were trying
minimize was the heat transfer between the staker and the bracket it was
mounted on.  Now keep in mind we were around 480F on our staker
temperatures.  The surface area between the 2 parts was around 1 1/2" sq.
There were 3 8-32 mounting bolts and 2 3/32" dowles to hold it together.  We
had a 1/4" insulator between the 2 pieces and a sandwich plate on the
outside that all the hardware went through.

At first we had g-7 in there as an insulator but it would delaminate after a
while.  I then tried some other fancy plastic and then a material called
Macor.  Macor is used as a gasket on the space shuttle windows and is almost
like a piece of ceramic tile.  Using a temperature gun and some temp paint I
took measurements on how much heat was transferred to the mounting bracket.

Now you would think you would see a big difference between the materials
that I had used but there was almost none.  Maybe 4F at the most.  Then just
as test I had a block of 303 Stainless made and put it in there.  The
temperature only went up about 8 to 10F from the macor temps.  All the heat
was being transfeered throught the hardware.  So I guess what I'm saying is
that you can insulate the surface of the head from the surface of the intake
manifold but you are still going to have some heat transfer though you
mounting hardware.  FYI the area I was measuring was consistant and I the
temp range I was in was aound 175F.

You could make some button head bushings out of g-7 and drill the mounting
holes in the manifold oversize so you don't have any metal to metal contact
at all.


----- Original Message -----
From: "Dan Bubb" <jdbubb@ix.netcom.com>
To: "ATS - Patrick Bureau" <pbureau@attbi.com>; "_Scirocco Mailing List"
<scirocco-l@scirocco.org>
Sent: Sunday, March 03, 2002 8:37 AM
Subject: Re: What about the port? was: Do these things work?


>
>
> > btw: the gasket on the intake manifold does nothing to inibate heat from
> > head to manifold..
> > Patrick
> >
>
>
> How do you figure? First of all the gasket is not paper thin as stated in
> the e-bay auction. It's around .06". Second whatever the gasket material
is
> it's non-metallic(except for the steel mesh inside which is largely
> irrelevant because it is not in contact with the head or manifold). It's
> coefficient of thermal conductivity is miniscule (on the order of
1/1000th)
> compared to aluminum.
> So, being the nitpicking dick that I am; saying the gasket does "nothing"
to
> inhibite heat transfer (hope you don't mind my editorial license on your
> statement) is clearly an incorrect statement.
> Somehow this product reminds me of the turbonated vacuum leak promoted by
> some british company that miraculously improved power and economy. The
> Vortex response?? Group Buy!! Group Buy!! Group Buy!!
> By the way, whatever happened to that wonderful 60 MPG carburetor? I'm
sure
> it was real! Probably squashed by the energy companies!
>
>
>
>
>
>
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