I was wondering if anyone has tried coating their apex seals with a NiCaSil coating? It's a lubricative coating that also helps deter detonation. We currently use NiCaSil coated cylinders for most of our race sleds. The NiCaSil cylinders also run a bit cooler versus a regular cylinder. Any thoughts on this?

Darril

 

Hi Darril,

It sounds like a great idea, but I wonder how any type of coating would affect the tolerances of the apex seal in conjunction with the apex seal groove. How thin is the NiCaSil coating? Who does NiCaSil coating?

 

Single, the NiCaSil coating is actually quite thin. Perhaps about as thin as say a Swain or JetHot coating. Except this coating does not really color anything. It looks like a nickel color. Currently, a mid west based company called U.S. Chrome has been doing the coatings. You can reach U.S. Chrome at 866-922-5066 or visit them at www.usnicom.com I wanted to consult with some of the board memebers first before i called, to see if this sort of thing may bear fruit. Thanks in advance,

Darril

 

well, one issue that you should research in more detail is what NiCaSil may/may not do to the surface of the rotor housing. i'm not familiar with NiCaSil (i mean, i've heard of it, but i've never had the need to research it) ... i don't know if you researched it already, but just in case ... you know?

anyway, what kind of car do you have (year/model), i'm asking because i believe the apex seals of all the turbo 13B's are already coated with molybdenum from Mazda, and i figured it might save you time and money just to use those for whatever you're doing.

1

 

Do the research on it. because there are a nuber of coatings that mazda puts on from the factory but you don't know what kind of chemical reactions that can happen between these coatings. This may cause adverse effects on the engine.

 

the coating does not rub or wear off under normal working conditions. We run NiCaSil coatings on our race sled cylinders, and the coating (actually its more like a plating) does not wear off on the pistons. Most OEM sled cylinders are NiCaSil, and manufacturers with their rep on the line wouldnt use the coating if it wasnt durable.

My personal car is a 93 CYM with 40,090 miles on it. I'm dont think i would have to invest in these types of seals for awhile. I was just investigating the possibility of a new coating for the apex seals.

Darril

 

nicasil is the newest technology in coatings. its nickel, cadmium, and silicone. it's a replacement for traditional teflon coatings. it reduces friction and heat and is tons more durable than teflon. let us know how it goes force fed. i don't know what it'll do for clearances though cause no matter how thin it is, that extra little bit of thickness coating the apex seal still has to be accounted for, to get the best tolerances.

 

btw, this thread should really be in the rotary performance section

 

How does a coating deter detonation? I can see it protecting the apex seals during detonation, but the only deterance for detonation that I know of is running a properly tuned engine. Also, why not coat all three sides of the rotor with this stuff? The sides of the rotor are like the face of a piston. Why protect just the apex seals?

 

excellent point!!!

 

A coating like this resists heat better. And since it has silicone in it, it makes the surface very slippery. One of the main reasons a apex seal locks up during detonation is because the surface of the apex seal has become so dry and abrasive, it doesnt have any lubrication to help it spin. The silicone would add just a bit more lubrication or slip to the surface of the apex seal. You wouldnt coat all three sides of the rotor because the coating would make the rotor heavy, and you'd have a slightly slower revving engine. Anyways, i found out that this stuff is just a plating, and that just wont work. A plating will eventually flake off, which is a no-no for rotaries. I'm looking into some other stuff right now.

Darril

 

good research, man! massive kudos to you ...

well, i'm, not going to try to speak for project84, but i think he was trying to target the detonation issue more than anything else, and i chimed in, simply because i had missed it in your original post.

everything you said the apex seal, during detonation is true ... in addition to the structural damage that it also experiences (may be able to liken it to a shockwave-type effect). but what i was trying to point out, is that the apex seal itself would be at the mercy of the heat created by the combustion events ... so the coating would have to serve the whole face of the rotor to have any chance of preventing detonation (maybe guarding against it would be a better way to put it - because my personal thoughts are that only timing and fuel changes are going really "prevent" it) ... that's all. it would be like coating a piston ring, and leaving the piston itself naked.

i'm not flaming ... just wanted to clarify, that's all.

i, for one, find this interesting, so keep checking in with whatever you find.

peace

 

A lot of times, thats exactly what Swain or Jet Hot do.

Darril

 

Very interesting. When I read "deters detonation", I was thinking like it was going to prevent detonation from happening. I don't think a coating for the apex seals can do that. What it looks like this stuff does is prevent the massive amounts of damage from occuring during detonation. Is that a better interpretation of what ForceFed said?