correct me if i am wrong, if you ceramic coat the exterior only, don't you think it is going to hold more heat inside?

 

YES!

As gases travel down the pipe they cool... as they cool they slow. If heat loss is limited the benefit should be a more efficient scavenge.

Coating the inside of the pipe would further insulate gases, but the added material would also take up some pipe volume & in doing so add some restriction/limit maximal flow.

While the coating on its own may not be worth much HP, its one more step in a holistic approach to optimising the system.

 

Doc, any news on the i/c's sent off for coating?

 

i got something black back in the mail yesterday...thanks doc.

 

The plot thickens....

 

The plot got so thick it had a coronary and died.

 

 

Go Heat!!

 

It appears to have done a Lazarus .

 

I've been meaning to ask you how much coating the cat-back exhaust cost. And I'm assuming you used a thermal barrier coating for the exhaust, not the thermal dispersement coating.

/gary

 

 

Bump from the grave...

I found a material from DEI (http://designengineering.com/products.asp?m=sp&pid=27) that I think would be suitable on the underside of the shield that is below the coolant tank. Goal is to reduce heat impinging onto the coolant tank. The material is about 3/16" thick. The material is designed to withstand 1750 F direct heat.

At this time, I don't have a Bentley manual. Is the shield easy to remove and replace?

Thanks.

 

That’s a neat product. I’m planning to add an extra thermal insulating layer to the firewall and exhaust channel and have this product http://speedzone24-7.com/adhesive.htm ; I may be changing products. To remove that heat shield, there are two other sections that must be removed first. I’ve removed it in the past but had the subframe and header out; it looks to be a difficult task without having those things out of the way. You might consider the application with the heat shield in place and only remove the header.

 

&Do you mean
this part?

If so it's pretty easy

This stuff is pretty neat too.
http://www.heatshieldproducts.com/hp_shield.php

 

The header heat shield is two 13mm bolt heads up top and easy to get to; the heat shield directly below the coolant over flow reservoir and attached to the firewall is another matter.

 

I was actually thinking about the other shield is above that one, that appears to continue down into the tunnel. But if the one in the picture is easy to take off, then I should do that also. Looking at the other shield, with the manifold shield removed, I could cover some (to behind the firewall) of the underside with the DEI stuff without having to remove it. I think I will also get some wrap for the tube that runs to the coolant tank.

 

Could there be issues with adding a heat reflective material to the inside of the header heat shield? Could the heat reflected back onto the header pose issues in the longrun?

And as far as some sort of data logging goes, any simple ideas for how I could measure meaningful temperature deltas?

 

Definitely. Just wasn't, am not, sure what he was shooting for.

 

With the header out of the way, the heat shield can be moved to access the firewall.


I used two layers of Thermo Tec's adhesive backed heat barrier over the firewall section behind the header.


While I was in the neighborhood I added some extra Dynamat to the exhaust channel forward of the shifter and applied a layer of the heat barrier over the length of the channel.

 

An update to the exhaust channel products, I've found Thermo-Tec's Suppressor mat to be an less expensive alternative to Dyanamat and when covered with DEI's floor and tunnel shield, the dual application provides a superior barrier against heat (and noise).



I've had a few headers with ceramic coating, for about a year I've had a black ceramic on the primary tubes and heat shield (not shown). Although it's limited coverage the two applications are effective at keeping engine bay temps reasonable.


The big story in my opinion is a new thermal barrier product using Zirconia. I had this coating applied to another owner's header recently.


Surface temps of the covered metal is significantly lower than the uncoated section. What is most amazing is how rapidly the surface cools after heated. Tube temps near the flange drop ~100F for every minute after shutdown, in ~7 minutes the primary tubes can be touched, and by 9 minutes they can be grasped without burning. A local oval track racer and engine builder was experiencing engine bay temps hot enough to boil fuel in the rail, after applying Zirconia coatings to header tubes, tops of pistons, and other areas to the engine, temps dropped dramatically. He claims coolant and oil temperature drops as well. Cradin is seeing very good results with Zirconia on piston crowns, dry film lubricant on skirts, and an oil dispersant on the undersides (the web site has not been updated).

After learning Zirconia could be applied to plasitcs and carbon composites, I tested the supercharger intaked duct to see if it could survive the curing process. The good news is the duct can survive but the bad news is the plastic locking insert for the vacuum tubes cannot. Too bad because the duct is a good canidate for a thermal barrier coating.