To Coat or Not to Coat!

[chuck will]

Greetings. I was wondering if any of you out in the GMC world have
taken to the Ceramic Coatings for the Doug Thornley Headers or some
orther brand of headers. I purchased the headers from "Mondello's in
Paso Robles" and have read a lot about the coating. The ceramic
coating cost is $ 220.00 plus the freight each way. Is it worth this
cost? The Thornley headers comes with a "Jet Hot" Industrial coating on
the outside. This coating however, does not cover the entire inside of
the headers.

In addition, the copper gasket supplied by Mondello (at an additional
cost) has two cylinder exhaust ports together in the center. Is this
correct or should the center ports be welded shut. I am confused here.
I thought the idea from the header was to keep all the exhaust ports
separated so they would increase the flow of the exhaust gases
independently of each other. If this is the case does it not seem
reasonable the thick copper gasket should be closed in the center for
this application? Need some Technical Help. Thanks Chuck

 

[bartz paul]

Chuck:

Where have you been. Back on April 12th, there was a lot of discussion
on Thorley headers and coating.

Let me know if you don't have access to e-mail from that era and I will
e-mail it to you.

If by the "two cylinder exhaust ports", you are talking about the
passages to the intake manifold, there was also previous discussion on
that. If you want to pursue that, the ports have to be plugged and then
you need to substitute an electrically operated choke on the carburetor
for the original choke. Same as above, if you don't have access to the
earlier discussion, let me know and I'll e-mail it to you.

Paul Bartz

> -----Original Message-----
> From: Chuck Will [SMTP:willa]
> Sent: Thursday, June 18, 1998 7:25 PM
> To: gmcmotorhome
> Subject: GMC: To Coat or Not to Coat!
>
> I was wondering if any of you out in the GMC world have taken to the
> Ceramic Coatings for the Doug Thornley Headers or some other brand of
> headers. I purchased the headers from "Mondello's in Paso Robles"
> and have read a lot about the coating. The ceramic
> coating cost is $ 220.00 plus the freight each way. Is it worth this
> cost? The Thornley headers comes with a "Jet Hot" Industrial coating
> on the outside. This coating however, does not cover the entire
> inside of the headers.
>
> In addition, the copper gasket supplied by Mondello (at an additional
> cost) has two cylinder exhaust ports together in the center. Is this
> correct or should the center ports be welded shut. I am confused
> here. I thought the idea from the header was to keep all the exhaust
> ports separated so they would increase the flow of the exhaust gases
> independently of each other. If this is the case does it not seem
> reasonable the thick copper gasket should be closed in the center for
> this application? Need some Technical Help. Thanks Chuck