Date:         Wed, 16 Mar 2005 11:53:13 -0600
Reply-To:     John Rodgers <inua@CHARTER.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         John Rodgers <inua@CHARTER.NET>
Subject:      Re: I win!!! the worse ever "westy part" picture...
Comments: To: Dennis <guskersthecat@YAHOO.COM>
In-Reply-To:  <vanagon%2005031612115038@GERRY.VANAGON.COM>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Dennis, I think you are quite right about this.

"Heat Ejection"

It's a big issue on these WBX engines, as well as the air cooled ones.
Anything that is done that retains heat is an engine killer. I think if
you really look closely at a WBX you can see many things that were done
to help get rid of the heat. I think the exhaust system with it's thin
material is an example. That relatively thin tubing gets rid of heat
better than thicker, longer lasting materials. If the vehicle is moving
down the road at a good clip, then that thin tubing sticking out
directly into the air with all the road induced air turbulance swirling
around the pipes is the best for heat ejection there is. However, if you
are stuck in rush hour traffic on the freeway the thin tubing ejecting
the heat helps to cook the engine and every thing in the engine
compartment. One might sacrifice the tubing by insulating it to retain
the heat until the exhaust can move it on out to the end of the tail
pipe, but the life of the tubing will be shortened, as will the cat and
the muffler.

It's a trade-off.

Ceramic coating of other parts, or insulating them, may have similar
effects. But always, it's a trade-off on the heat migration.

Regards,

John Rodgers
88 GL Driver



Dennis wrote:

>An aside...I'm not sure ceramic coating would be a great idea for an engine
>block.  The product I used on my exhaust (Black Satin, Techline Coatings)
>claims 30%ish heat rejection.  On an engine block, that would mean a fair
>amount of heat retained by the block that otherwise would be radiated into
>the engine compartment.  Then one wonders as to the thermal design
>tolerances.
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