High Temp RTV on Exhaust Gaskets

I recently ran into another case where someone sealed exhaust gaskets
with red high temperature RTV silicon sealant. I don't know off hand
what the temperature rating is for RTV but it has to be way lower than
what the exhaust flange sees. I will say the flanges and gaskets (the
thick spirotalic no blo style) were not leaking. Am I right in
thinking the lack of leakage is due more to the gaskets working as
required than the RTV?

John Dupre'

John wrote:
I recently ran into another case where someone sealed exhaust gaskets
with red high temperature RTV silicon sealant. I don't know off hand
what the temperature rating is for RTV but it has to be way lower than
what the exhaust flange sees. I will say the flanges and gaskets (the
thick spirotalic no blo style) were not leaking. Am I right in
thinking the lack of leakage is due more to the gaskets working as
required than the RTV?

John Dupre'

There's a car racer racing a Mazda rotary that uses rtv with no gasket
at all on the exhaust manifold. (Rotary exhaust temps make Lyc exhaust
temps look rather cool.) He says that the actual temp of the manifold
itself at the block is actually the same as the engine block. Makes
sense, if you think about it. Of course, the Mazda is water cooled &
won't be as hot as the cyl head on an air cooled Lyc. Is red rtv rated
to ~450 degrees?

Charlie

On Sun, 19 Nov 2006 21:27:26 -0600, Charlie
wrote:

John wrote:
I recently ran into another case where someone sealed exhaust gaskets
with red high temperature RTV silicon sealant. I don't know off hand
what the temperature rating is for RTV but it has to be way lower than
what the exhaust flange sees. I will say the flanges and gaskets (the
thick spirotalic no blo style) were not leaking. Am I right in
thinking the lack of leakage is due more to the gaskets working as
required than the RTV?

John Dupre'

There's a car racer racing a Mazda rotary that uses rtv with no gasket
at all on the exhaust manifold. (Rotary exhaust temps make Lyc exhaust
temps look rather cool.) He says that the actual temp of the manifold
itself at the block is actually the same as the engine block. Makes
sense, if you think about it. Of course, the Mazda is water cooled &
won't be as hot as the cyl head on an air cooled Lyc. Is red rtv rated
to ~450 degrees?

Charlie
Ultra Copper is rated for intermittent 700F.Red Hi-Temp is rated for
650F. Ultra Grey also 650F. Ultra Blue 500F.Ultra black also 650F.

The stuff DOES work well on exhaust flanges, as well asfire-box seals
on RV furnaces etc.

--
Posted via a free Usenet account from http://www.teranews.com

Ultra Grey also 650F. Ultra Blue 500F.Ultra black also 650F.

The stuff DOES work well on exhaust flanges, as well asfire-box seals
on RV furnaces etc.


Van's airplanes have furnaces?

"J.Kahn" wrote in message
. ..
Ultra Grey also 650F. Ultra Blue 500F.Ultra black also 650F.

The stuff DOES work well on exhaust flanges, as well asfire-box seals
on RV furnaces etc.


Van's airplanes have furnaces?

chuckle Perhaps he meant furnaces on (R)ecreational (V)ehicles? g
--
Jim in NC

I see a lot of people and other mechanics use silicone to stick the gaskets
to the cylinder while they get the exhaust positioned and the hardware put
on. I just use saftey wire to hold them up, then pull the wire when I'm
done. The silicone won't hurt anything, but to me just looks kind of
cheesy.


"John" wrote in message
ups.com...
I recently ran into another case where someone sealed exhaust gaskets
with red high temperature RTV silicon sealant. I don't know off hand
what the temperature rating is for RTV but it has to be way lower than
what the exhaust flange sees. I will say the flanges and gaskets (the
thick spirotalic no blo style) were not leaking. Am I right in
thinking the lack of leakage is due more to the gaskets working as
required than the RTV?

John Dupre'

Chris Jella wrote:
I see a lot of people and other mechanics use silicone to stick the gaskets
to the cylinder while they get the exhaust positioned and the hardware put
on. I just use saftey wire to hold them up, then pull the wire when I'm
done. The silicone won't hurt anything, but to me just looks kind of
cheesy.


"John" wrote in message
ups.com...
I recently ran into another case where someone sealed exhaust gaskets
with red high temperature RTV silicon sealant. I don't know off hand
what the temperature rating is for RTV but it has to be way lower than
what the exhaust flange sees. I will say the flanges and gaskets (the
thick spirotalic no blo style) were not leaking. Am I right in
thinking the lack of leakage is due more to the gaskets working as
required than the RTV?

John Dupre'


When it comes to temporary security of the gasket while I work the
exhaust stack in place I used to use a drilling wax and now use a
similar product called Stickit. It allows the gasket to stick in place
and then melts away when the engine is run.

John Dupre'