Ceramic coated rotor users need help!
 

Ok i want to do some test on ceramic coated rotor core heat retention and disipation.

It is inevitable that heat will get past the ceramic coating both from through the rotor face by conduction through the ceramic coating, and through the side housings.

I just want to test to make sure heat isnt soaking into the rotor core, and then after shut down the rotor doesnt cool off as quick as a non coated rotor...sorta how a car will boil over after shut down due to no coolant circulation.

So basicly i want to see what operation oil temps are after the car is fully warmed up and ran around, and then start the car at intervols after shut down to check the oil temps.


Am i making any sense?

I understand what you are saying -- for the same reasons the coating reduces the heat transfer INTO the rotors during combustion, it will also reduce the heat transfer FROM the rotors after shut-down. I have coated rotors in my new engine, so I can see how my oil temps behave. However, I don't have data from the before the change, so I won't really be able to compare. I don't expect this to be an issue, however.

-Max

so would you say your engine cools down fine?
Also are the rotors just coated on teh face or the sides also?


Main reason why i am wondering this is, if i were to cermet the rotor housings and side housings, if the rotor when ceramic coated will cool through just oil alone or with very little metal conductance.

goal is to use more of the power potential of the combustion process by redirecting the heat to making the rotor move and go out the exhaust than get soaked up by the rotor and housings.

I'd be worried about it flaking off and trashing the motor....I really like the idea though.
more research please.

My car is still at the shop -- by "I can see" I meant that I don't have it yet, but I can see now that my message wasn't very clear. :) I got the rotor faces coated with thermal barrier stuff, but that is my only internal engine treatment. Still, I don't expect any problems. I don't care much how fast or slowly it cools down after I shut it off because I don't think it will matter.

-Max

The ceramic coatings don't have the same properties as some of the chrome coatings. I don't think I've ever heard of a ceramic flaking off.

- Steiner

yeah im not worried about the ceramic flaking. im just wondering about heat retention and disipation.


I guess i am going to use myself as a test, and will get some guages set up, so i can record before and after. results might be off because i will be doing the preliminary test on a old engine, with quite a few miles on it!

This is a common problem from what I have read and talked to people about. The older techniques sucked, and stuff did not adhere very well, it would have a tendency to flake off in large sheets.

Not the same application as internal parts, but if you have ever looked at older mild steel headers with ceramic coating, invariably there are small patches and I some cases large quantities of coating missing from the upper portion of the collector where heat expansion has had the most effect on the tubing.

If you use ceramic apex seals with a ceramic coated rotor housing, in theory you would have zero friction. Sure it wears, but it comes off in dust form, meaning that it just gets shot out the exhaust with the rest of the gasses. Also, ceramic dosen't flake, it just out right breaks if it fails, which is hardly ever (Usually on like 24hr cars and stuff)

the ceramic coat will certaintly force more heat (and therefore power) to go into moving the rotor and spinning the turbo. As for the cooling issues, you should see slightly lower oil temps while running. i can't think of any significant surface contact that would be occuring near the rotor faces so --and correct me if i'm wrong about the contact-- you wouldn't notice much of a difference in cool down from an uncoated-rotor engine. my reasoning is that, since there isn't much contact between the rotor face and a viable heat sink, the heat trapped in the rotors after shutdown is probably dissipating accross some other boundary, which would presumably not be ceramic coated, and therefore the ceramic wouldn't have an effect.

i was talking to my shop foreman about this, and he was saying that with coated rotors and housings, that the heat would be traped in the housing, keeping the rotor hot and expanded, and if you start the car hot the rotor will be expanded in relation to the housing, and that the rotor might scrape the housing n stuff.

I personally don't agree with this.

thermal barrier on the rotor face will reduce the rotor temp.
it may increase the water temp a bit but most of the extra heat
goes out the exhaust, its not trapped.
running or not the thermal barrier doesnt change what it does.
also i dont think there is anyone putting a ceramic thermal barrier coating on the housings.
coated housings would keep heat from making it to the coolant which i would think might be bad.

matt

I meant like a cermet type coating for the housings.

There are a couple people doing ceramic coatings on housings. The idea is that you still keep more heat within the combustion chamber and thus should produce more power. The 787B used a cermit coating which JHB in Canada offers. You may want to talk to them about whether or not they see differences with oil and coolant temps while running.

- Steiner

I will know soon enough, will be building a motor with their housings for the spring.
matt

Excellent keep us posted with results. I'll be going with the coating that Scalliwag is developing when he gets a chance to coat my housings. What seals are you planning on going with?

- Steiner

I am hoping to get my hands on some of NRS Ceramic apex seals, if he comes up with a good price that is.

later
matt

In terms of the "hot rotor still expanded from heat" issue, remember that the rotors are iron and the housings are aluminum. The rotors won't expand very much compared to the housings, so even if the rotor stays hotter relative to the housing than an uncoated engine, I seriously doubt the rotor heat expansion would ever be a problem.

-Max