I'll be turbocharging my '82 BJ60 and I am hearing a lot about how it would be good to ceramic coat the exhaust header to keep underhood temperatures down. Anyone have any information on that as to how effective it is? Are there any other benefits?
Ceramic coated headers are supposed to help keep some of the heat out of the engine compartment, but I don't have...and haven't seen...any empirical data to support this.
I have put a set of ceramic coated headers in my Dakota, and they worked great for the first month or so of day-to-day driving. Unfortunately, on my first off-road trip, the limited air-flow through the engine compartment lead to higher under-hood temps, and the new headers actually scorched three of my plug wires that were within 2-3 inches from the headers.
I honestly think that I wouldn't have had to drive ~35 miles out of Colorado backcountry with a miss on two cylinders if I'd went with ceramic coated headers of a different design...like a tri-Y.
I guess in a roundabout way, the moral of the story is that ROUTING of the header is as important as ceramic coating is, and, if you can find an optimally routed header & get it ceramic coated, I'd suspect you could have your cake & eat it too!
So basically what you are saying is that if I avoid vital components which are affected by heat then I should be going with the ceramic coating? My Land Cruiser is diesel so there is NO plug wires to deal with and the other wiring, brakes etc. are on the opposite side of the engine compartment.
You likely won't see a difference in the engine temps, as this is a function of your cooling system... i.e. - if you have a 195 degree thermostat, your engine temps will revolve around that basic figure. Let's face it, a 5, 10, or even 20 degree change in the nominal underhood temperature will make very little difference in how quickly your motor heats up, and absolutely no difference in the normal reading on your temp guage, as the thermostat still opens up at 195 degrees.
The claim for ceramic coated headers is to lower underhood temperatures...not your actual block/engine temps. There are several benefits for doing this, but what are probably the biggest two are:
1.) In tight engine compartments, these headers may help protect surrounding components (wires, hoses, electronics, etc.).
2.) As most stock air intake systems draw in air from the engine compartment, any change in the underhood temps will carry some form of impact in performance and, possibly, fuel economy. This is due to the pure & simple fact that cooler air is denser air, and the more air you can get into each cylinder during the intake cycle, the more fuel can be carried in with it.