AtomicRex

iTrader: (10)

Hiya guys,

According to the manual the rotors come with a "Soft coating" around the outer edge of each side of the rotor. Is this something that can be put back on?

Cheers

Jon

Gurew

iTrader: (4)

the coating is a gold color and its on the side faces of the rotor. i wouldnt worry too much about it...just get your rotating assembly clearanced and balanced and you will be good to go

ronbros3

the coating on outer side of rotors was like a bearing material, so when in hi boost &rpm the Eshaft would bend and let rotors touch side plates, the coating was for rubbing without digging into plate.

most of the time its half worn away anyway, polished off or machined off, so dont worry about it. nobody else seems to care.

and nothing is ever perfect!

Gurew

iTrader: (4)

heh, all my engine builds are perfect

marco137

iTrader: (1)

for a moment I thought you were talking about ceramic coating the rotor faces to reduce heat transfer- does anyone know if this has been tried, and if it gave any benefit?

Mahjik

iTrader: (1)

Sure, a lot of people have done it:



No proof to any real benefits, but I could think of worse ways to waste money.

quattro4now

The only benefits that I've come across are lower oil temps (that one is obvious) and lower knock readings.

https://www.rx7club.com/showthread.p...light=coatings

Mahjik

iTrader: (1)

There hasn't been any real scientific studies of the coatings on a rotary, at least not on this forum. Knock reading is NOT the best indicator as there are so many things which influence that reading (since it's basically just a small microphone). Also, Batman is/was probably the least scientific person on the forum.

I never got a chance to really use mine, but the "idea" is around the heat which is absorbed by the rotors. The idea is that the less heat the rotors are absorbing, the more heat can be used in the combustion cycle for a better burn... However, others theorize that the engine is designed with the rotors retaining that heat and thus requires it for maximum performance.... It's still basically unproven which is why it's not a common practice.

quattro4now

Hey now, I'm working with what I can find!

That thread is one of the few that I could recall any evidence being presented aside from hearsay. I didn't call it proof but, it is something.

I've read the views both for and against and understand what they're getting at. I believe its not a matter of who's right but rather who's MORE right. While its not the most cost effective, I think the rotor coats are more of a pro than a con.

Turblown

iTrader: (12)

You will notice a big drop in oil temps from doing it.

ronbros3

and a lot more heat into the cooling jackets== overheat and possbly chance of the great DETONate,

but im sure an unusual tune &water could make it work. lot of torque while it lasted bout 1/2 hr.

i did it back in 1998, factory tune FC, blew the engine into the next county

DFW RX-7 Cook

iTrader: (1)

I’ve actually coated several rotors over the years and no one has ever blown a motor. The general benefits are lower oil temps and a safety margin if your assembly becomes unbalanced and the rotor strikes the irons.

The sides are generally done with a Dry lube which impregnates into the metal a few mills and makes the surface slicker when friction is applied, for the protection aspect.

The faces are coated with a ceramic coating same as used on piston tops which help reduce heat soak into the rotor lowering oil temps.

Several racers do this and say it helps reduce fuel consumption and helps in maintaining a constant engine temp in respect to thermal dynamics.

Unfortunately with the rotary motors design some of the benefits the piston guys see don’t occur such a Peristaltic ballast reduction.

stylEmon

iTrader: (2)

Ditto.

My rotors were coated by turblown; I have been running 20psi on pump gas for a while without problems. My oil temps are very low compared to other FCs I have seen.