Date:         Wed, 18 Dec 1996 12:56:23 -0800
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Todd Francis <tbf@pacifier.com>
Subject:      Advice Rebuilding an 84  : head coating

ROGunter@aol.com wrote:
> 
> Thanks Todd,
> 
>      What do you mean by "coating" a head?  Are you talking about coating the
> surface that will touch the block with something that prevents contact
> between the metal surfaces of the head and the block?  What do they coat the
> head with?
> 
> 

Hi Russell:
I'm sorry you got only half of the message I origanally wrote. I have
been trying for about two days to get this message out. It goes to the
list and half turns up missing. Can't figure it out. I have written
other messages before and after and they have been working. Oh well, to
the question at hand: I have been working with a shop here in
Portland,OR. that applies Ceramic coating to engine parts. When I
rebuilt my engine I bought new heads and had him ceramic coat the
combustion chambers in order to keep unwanted heat out of the head ( you
see, this ceramic coating is a high performance thermal barrier sort of
like is used on the bottom of the space shuttle. In a engine application
it is intended to keep the heat in the exhaust and blow it out the pipe
instead of absorbing it into the head. In race car applications it is
supposed to increase power.) and they also coated the whole surface
surface surrounding the combustion chambers that touches the coolant. I
figured that ceramic should not corrode so it should be perfect for
controling the pitting of the heads. Also since this stuff is a thermal
barrier it should keep some of the heat of the head from getting to the
large rubber head gaskets which I assume whould add to the life of the
gasket, and with the history of these gaskets any help is welcome. I
also had the exhaust ports coated to keep heat from the head and I had
the valve heads coated. They say the valves keep cooler when they are
done. I have about 40,000 miles since rebuild with no problems. I won't
really be able to tell how well things are going until I take it apart
again, so it will be (hopefully) a while till I can really complete my
report. 
I had a couple of other wc engines done also. These heads were used and
badly pitted from corrosion. In this case the shop first filled the pits
with ceramic putty then covered everything with ceramic coating , then
they are baked at 300 degrees to cure the coating just like the new
heads I had done. The seal surface came out very smooth. So far we
havn't had any trouble with those heads either.
 I also had a couple of air cooled race engines (type 4) done. This was
done strictly to keep as much heat out of the head as possible. I have
not done tests to find out if it helps, I just have relied on things I
have heard and magazine articles that have talked about the stuff and
swear it is the hot ticket (cool ticket?).

Todd Francis
91 Tristar
86 Westy Syncro