epion2985

well ceramic coating prevents it from being absorbed in to the rotor right. The nature of the material is that it reflecs or repells heat, not sure whats the correct term. So if you cover a surface with it and heat cant get absorbed in to it it has to go somewhere right? And it has 2 places to go, the rotor housing and in to the coolant and out the exaust port in to the exast manifold, turbo exaust housing, etc out of the car. I dont see where the heat would get TRAPPED? some will get absorbed by the rotor, the ceramic coating doesnt repell 100%, some will get absorbed in to the rotor housing and then will be absorbed by the coolant, and when the stroke with come to the exaust part everything int he chamber with be shoved out in to the exaust port and eventually out of the car.

As far as mazda research and engineering goes I dont know what to really think of it but they made some pretty stupid desidions while making this car so I wouldnt dought they overlooked or didnt look or didnt consider or chose to go another way here and there for whatever the reasons they had. But as many people here know over the time the car has been out people found countless things to be improved that were really badly designed. So I raise the question, if they are so smart and their knowledge and their word should be taken with no questioning as the best possible way to do this then why all the poorly designed aspects?

j9fd3s

iTrader: (3)

they have spent a lot more time and dollars making the thing run in the last 30 years than anyone else. also just because the reason for doing something isnt immediately transparent doesnt make it bad.

and furthermore oem's cant put the best materials into a design because they are trying to make money. how many ceramic coated pistons, and iconel exhausts do you find in a sub $40,000 new car?

rxseven

Just so that you know epion, the 4-rotor engine in the Leman's car had ceramic apex seals with a certain ingrediant to RAISE the heat conductivity to reduce the localized heat build up in that area. As for your low opinion of Mazda engineers, being an engineer myself, all I can say is it is easy to be a Monday morning quarterback. No design is perfect, there is always a compromise. When I read their papers, atleast I know their credentials and that they are the leading authority on rotary engine design. I can't say the same for most people posting in forums on the internet though.

maxcooper

I went with Ianetti 2mm 1-piece seals.

-Max

maxcooper

I don't think the coating would hold up on the side housings. In fact, I am quite sure that would be a bad idea. There are coatings and processes that can reduce friction in that area, but I don't think there is anything in the market that would both provide a thermal barrier and survive the seals riding on it.

I don't think any of the thermal barrier coatings would work on the inside of the rotor housings, either. You wouldn't want to trap heat anywhere else, except perhaps on the insides of the exhaust ports in the rotor housings. I don't know of anyone doing that, though.

BATMAN and I had the rotor faces coated. No seals ride on that area.

-Max

maxcooper

If the increased temperature and pressure from the coating makes you more likely to detonate at X psi of boost, you should be able to reduce the boost such that you get the same peak chamber pressure & temp that you would without the coated rotors. You should still end up with more power (since the pressure and temp will not drop as fast over the power stroke), with a similar propensity for detonation (since the peaks are the same), at a lower boost pressure.

I can imagine only a few possible side effects of coating the rotors that would be bad:

1. Overtax the cooling system. We've got remedies for this, so I am not that worried. Perhaps the only insurmountable problem would be if the extra heat kills the rotor housings.

2. Melt your turbine. Hopefully this wouldn't happen with a "normal" turbine, but I'm going Inconel anyway. I don't expect it to be a problem.

3. Coating flakes off. Only time will tell. if this happens, the particular coating used is just not up to the task or was applied incorrectly. Perhaps other prep or a different coating would survive. It might be worth another try if the coating does seem to have benefits. I'm only dojng one test, though -- if this happens to my engine I'll let someone else test the alternatives.

4. The extra thickness of the coating causes the rotors to hit the rotor housing cusps. Only time will tell. I don't think this will happen, but if there are noticably good effects from the coating, you could just coat the tubs, or remove a little material from the rotor in the critical area to make clearance for the coating and try again. This one is easy to solve, but I sure hope it doesn't happen to my engine. I would try it again if this happens, though.

Another issue is whether the coating changes the weight enough to throw the balance off. I didn't weigh my rotors before and after, so I don't know how much the coating weighs. I wouldn't expect it to change the weight much. I did have my rotating assembly balanced after the coating was applied, mostly because I want to rev high, but partially to ward off any imbalance the coating may have otherwise caused.

-Max

BATMAN

1. I am monitoring the PFC commander and see no evidence of the cooling system being over taxed.

2. My turbines are not factory, BNR 2

3. This may or may not happen.

4. The coating is half the thickness as a piece of paper. We had the apex seals groves coated. Seals fit right inside no problem.

j9fd3s

iTrader: (3)

3. if it comes off, you prolly won't be able to tell. i have an fc turbo thats ceramic coated, and it burned off in under 5k miles, it really just changed color back to rusty cast iron

maxcooper

You had the rotor faces coated, or some other part? It sounds like you mean a turbine housing from the turbo of an FC, but I'm not sure how applicable that experience is to having engine rotors coated.

I will be able to tell when I blow my engine again and have it torn down.

-Max

j9fd3s

iTrader: (3)

they are both hot?

lol@ #2, yeah i guess we'll see

maxcooper

I think the coating is different than what is commonly used on downpipes, etc. Most of the exhaust stuff that I have seen coated is black, and the rotor coating stuff is beige. It might just be a color additive since people won't want beige headers, but who knows. I have heard of a lot of the downpipe coatings flaking off.

Also, I don't think the metal the coating is on gets as hot as exhaust applications since it is cooled by oil on the inside of the rotor. I imagine the surface gets just as hot from the combustion, but perhaps the base metal being cooler will help to prevent flaking.

-Max

80-CU.IN.T

Very Interesting - I talked with Swain Technologies for a good 30 minutes on the phone back is 2001. I knew several people that had used their Gold barrier coating on piston tops. The same people used Swain's black (Slippery) coating for the piston skirts. All of the people were happy with the results.

Swain technologies told me that they did several rotaries back in the late 80s early 90s. The coating didn't last because of the high heat produced from a rotary. I could not understand why a rotaries combustion temperatures were so much higher than a standard piston motors. I thought they would remain the same given equal compression ratios and boost pressures. The person I talked with started going into thermal dynamics and it was difficult for me to follow what he told me. I have notes somewhere of who I spoke with. It stile doesn't make sense and I stile don't understand why. I understand why the exhaust gasses are so much hotter but not combustion chambers. I was talked out of using there product by them because they were worried of it flaking off and destroying my turbine wheel. I am very cirios to see if they have changed the materials in there coating processes since our discussion.

epion2985

exactly. That proves my point that the car is not made the "best" possible way because it wouldnt be cost eficient. That answers the question of "if thats such a great idea why didnt the mazda engineers do this".

------------------

first of all may I quote you:

"in the Leman's car had ceramic apex seals with a certain ingrediant to RAISE the heat conductivity"

now let be highlight this part for you:

"with a certain ingrediant "

those were ENGINEERED to do that, normal ceramic coatings are made to repell heat not improve conductivity. They insulate because they make a good barier because they are full of air. The once used in the 4 rotor engine were chemicaly altered to do what they did. That wasnt your general run of the mill ceramic material.

----------------


first of all I was refering to the BAD BAD things. Like you cant justify the fact that the intercooler is too small with any credentials. I am not claiming to be a termal engineer or any sort of authority on the subject but I am not stupid, I am well informed and I am majoring in engineering myself so i have a pretty good common sence when it comes to obvious things.

Credentials or no, they messed up. I am not saying they are stupid but they did overlook alot of thing, weather it was on purpose or because they messed up things like inadequatly sized intercooler, inadequate cooling systemt hat runs very close to the margin or where it does become inadequate, like a hot day hits and your engine gets airborne. I was talking about those aspects.

7racer

Max and Batman,

what kind of effect do you think water injection would have on the coating and ceramic apex seals?

neofreak

The stock IC and radiator are perfectly fine for stock cars. You can't blame age and wear -- of course the radiator is going to split eventually. I've driven in 110f heat in LA, and the highest temps I got were 195, well within reason. Of course this was a properly maintained car, and not everyone manages that.

If the designers were terribly wrong, don't you think they would have changed the design when they had the chance? After all, the FD had two revisions. Neither the rad or the IC changed between 96-98 or 99-02. (besides fan blade shape)

rxseven

That reason would be because rotaries are not as efficient as piston engines. More energy is wasted in the form of heat in a rotary rather than being transferred to the crank.

rxseven

You are missing the point which is that Mazda tried to increase internal thermal conductivity for their motor not decrease it like what this thread is about in the first place. You want more heat to be transferred out of the apex seal and to the rotor housing and rotor.

TrentO

I have a friend who runs a 12 A streetport with the cermaic coating on the rotor faces in a road race class ( you don't get much more heat than 2 hour enduros running the motor from 5000-8500 rpm non-stop). The engine by far outpulls the other engines in the class and it ran an entire season without issue (6 race weekends, about 6 hours of pure track time per event). He makes more power than the other street port motors and doesn't have heat issues. We have to run the stock carb, so the porting isn't creating the power, the carb is a stocker off a junkyard car, so that's not the source. In my opinion the ceramic coating is worth doing as the guy probably has 5 to 10 hp on the rest of us.

-Trent

BATMAN

NOt sure.

epion2985

well the fact that it had multiple revisions already said that they screwed up and had to come back and fix it. Also I am not sure but werent there 3 or 4 recalls? And I am talking about the 3rd gen. I belive 1 was to lower the pressure in the cooling system, fan blade change like you said, something with the radiator cap, and something else.

As far as your opinion goes its no fact. Just because you had good luck with your car doesnt make it perfect for the rest of us. I know for a fact that MANY members here have (and I have read many threads time and time over it is brought up) complained and disscussed inadequate ic sizing and other badly engineered aspects. I am by far not saying they did a bad job or its a bad car or they dont know whatt hey are doing. All I am saying is that they mis-engineered a thing or two to save cost or time or just didnt expect things to work out the way they did, whatever the reasons were it is so and we have to deal with it.




well just because what they chose to do doesnt make it gods decree ok. They are not perfect, it is ricer/idiot mentality to go asume this must be the best thing just because they did it that way. More to it its an idiots mentality to look at it so close minded, look at the big picture, who said we and them are trying to achive the same thing?

1. They have plenty of power, 700hp to be somewhat exact. They had preoblems with cooling with all that power, so they tried to get more heat in to the cooling system and out of the engine. They went fighting a battle to make their engines last, to prevent carbon build up, to get 20 more hp out of their engine. They wanted to cool things down and they did what they did to do so.

2. people here who did it, did it to squize out some more power out of their engines on a budget, with emittion regulations hindering every modification. To prevent carbon build up to improve durability and lasting of the engine. The 4 rotor LEmans engine is torn down every race, most people here dont have the time and money to do that.

So you see the goals are totaly different so it is foolish to go and blindly follow someone who knows what they are doing without 1. understanding what they are really trying to achive and why. and 2. without considering the circumstances of budget and street legal regulations, emition regulations, time, and aplication.



Proof at last. We have a few people here who tryed it and are very happy with results and think it is totaly worth it. So no need to bash it and try to prove it wrong with out really understanding the how and why and under what sircumstances and with what aplication criteria. Also results speek for themselves and we have them and we like them so why the argument?

80-CU.IN.T

Yes - The energy is wasted and goes out the exhaust port which increases the exhaust gas temperature greatly compared to a piston motor BUT the combustion temperature should remain relatively the same as a piston motor. Piston domes & rotor surfaces should be exposed to the same temperatures. A rotor does have a larger surface area compared to a piston but it also is exposed to oil which should cause no to burn as evenly and not produce as much heat "Theoretically." Back in 2001 Swain Teck talked me out of there process for reasons I explained before. I just could not figure out why there material worked on a piston dome and wouldn't work on a rotor surface. Just look the shape of piston domes in high compression motors and tell me the flame fronts don't create hot spots.

KevinK2

The stock IC is not fine. It is undersized, forcing the engine to run less efficiently. Mazda redesigned the IC ducting to stop engine damage during sustained high speeds. If you never exceed 195 water temps, you are tricking the fans to come on below the stock 221F min set point, or never get stuck in traffic with ac off. The rad is sized properly for normal use.

The design was good and bad. Bad includes puny IC, ecu with 3k hesitation likely, and a twin-t control design too complex .... simple faults (solenoid) not detected by mechanics (used to mpvs and sedans) would result in very expensive repairs for mazda or others. I think toyota supra tt conrol was simpler, and used more electrical actuators vs pneumatic (fewer brittle hoses, tanks, and check valves).

on thread, agree with max. coating should reduce boost (and backpressure) needed to hit a fixed hp target, and increase bsfc due to less % heat loss to cooling system.

BATMAN

actually the stock IC is fine if ur running stock setup in cold Japanese Winter with 100 octane

Fatman0203

*ding ding ding* we got a winner.

I mean going around japan, with an ambient 70 degrees, and a light breeze. Running 100 octane, laughing at what people call "detonation". The you have those pour souls in Cali with 92 **** gas, and 105+ temps. Oh yea , we see the problem.

BATMAN

actually our octane just got bumped down to 91.

******* Liberals........