Schnell Gelb

I am rebuilding my M96 and need advice on the value/wisdom of getting a ceramic coating on the top of the pistons and a different coating on the skirt.The better M96 rebuilders seem to use coatings
Swain seem to be often mentioned for other engines and their prices seem reasonable :
http://swaintech.com/race-coatings/a...s-price-sheet/
Does anyone have experience to share on which specific coating to choose and who to apply it?
I do not plan to track the car but do drive it hard sometimes and plan to keep it for many years (assuming the rebuild goes well!)
Thanks for any advice and I hope this thread will be of interest to others rebuilding the M96.

dcdrechsel

SpeedrII fixed a rod bearing and along the way had his pistons coated .I think a search on his handle will provide more info .

Tiger03447

I had a maniold on an older Nissan Slalom car done by swain..still seems OK after about 3 years..also drive it on the street some..A local engine builder uses Swain for ceramic/heat coatings for nitrous cars and some that are blown...Seems OK by him too. Central CT coatings is about the best around here. Does ceramic coatings on pistons and crowns and inside and outside of headers and manifolds. I use him a lot..52 village ST E. Hartford CT. 860-528-8281. Does great work..will do you chassis too if you want it done. Been in business for over 30 years. Mixes his own powders great guy to work with named Gene Schaeffer..good prices too. Check it out...Rich

Schnell Gelb

Thanks for that, yes the Flying Finn did get his coated -but in Finland with a local treatment. There seem to be several rival treatments in the U.S.A. and I am curious about which is the best to use.
The older/cheap ceramic coatings for the piston crowns can crack/flake which would be a disaster.The cheap skirt coatings are sometimes considered 'break-in' only treatments and wear off within a 1000 miles.They are extensively scuffed within a few hundred miles. I can't find any reliable reviews .There are plenty of ricer/snake oil hits on Google.Swain andd Polydyn are often mentioned.

Schnell Gelb

Thanks Rich, I'll contact Herr Schaeffer.

Macster

Piston/coating maker should have some guidelines. The coating if any has to be chosen with the cylinder material in mind.

As you probably know, the stock engine comes with some kind of iron coating on the piston skirts.

Schnell Gelb

Thanks Macaster, I had read about the iron coating on the piston skirt . I found no mention of using iron coatings in the aftermarket -all Moly/poly/teflon .

Macster

Well, I haven't really kept up on the latest coatings craze.

I can recall over the years, more years than I want to remember, coatings for pistons come and go. Some company developes a coating and wondrous benefits are touted and soon it is being applied to everything.

Then the hubbub dies down and that's that until the next miracle coating comes around.

Teflon has been around a while. There's a peeling risk IIRC, though of course no doubt by this time that has been improved upon.

(Oh, there used to be teflon buttons used, too. The skirt was drilled and these buttons installed. The piston skirt never actually made contact with the cylinder wall.)

In the case of the factory application of iron I think this is intended to be a temporary thing to facilitate proper engine break in to forestall piston to cylinder contact at least initially and for sometime afterwards.

The best coating is really none. There is no issue about its proper application, it is one less thing to go wrong, come loose, flake, peel, or crack or otherwise degrade.

The best solution is properly selected cylinder and piston material, clearances, finishes, and suitable lubrication and cooling (in the case of the Porsche engines provided by oil jets one for each piston). This all has to be addressed anyhow as no coating will ever eliminate the need for the above.

Byprodriver

I recommend Embee Performance coatings in Santa Ana CA.

I get any exhaust pipes coated inside & out with their thermal barrier coating

They offer piston coatings & new JE pistons with the coatings, leading me to think they do most of JE's coatings, since they are local, but that's just my guess. When I worked at Stillen (2000) Embee did all their coating work.

LN pistons used to come with coated side skirts on their JE pistons.

Embee also does Mil-spec coatings.

Schnell Gelb

Bill,
Thanks for that suggestion.I really appreciate the time you take to help us noobs!
The credentials you mentioned are impressive. They are conveniently close to other companies I already use :- Marine Crankshaft (David) and Costa Mesa R&D (Mr.John Edwards)

Flat6 Innovations

This can be a slippery slope.. Especially in regard to optimum running clearances and micro welding of rings to ring lands. The micro welding is more of an issue when piston crowns or chambers are coated, as the heat is reflected back to the top ring land.

I move my top ring land down when using coatings, and I will often treat the lands differently as well.

I also find that engines with crown and chamber coatings will often like much less total timing that non coated components do.

My recommendations to a first time builder is to not create an unknown variable by introducing coatings to the mix. Keep it simple and work your way up- that's how I instruct my engine mechanical classes.

Not all coatings are created equally... Some last a number of hours, others for a decade or longer. I've been using coatings since 1995, for my first decade I learned something new every time, generally the lesson was a hard one... You'll read lots about coatings in forums, but trust that it's mostly parroted information posted by some guy who wants to act like he's been there and done that; yet he doesn't even change his own friggin oil. Lots if those clowns out here on the net......

Schnell Gelb

Thanks Jake.
I find it very difficult to find reliable info on the subject.So much sounds like snake oil.
So far, I had concluded the only factual measure was how long the company had been in business -so Poly-Dyn and Swain seemed interesting.
I had abandoned 'ceramic' coating on the crowns because mine is not a turbo and runs a stock tune.
The skirt scuffing prevention is interesting .I found positive references to "abradable powder coating" by U.S. Chrome & Line2Line
http://www.enginebuildermag.com/2014...asting-longer/
But even after 90,000 miles my 3.2L pistons have all the machining marks on the skirt and crown ,so perhaps coatings are a minor issue on a stock engine ?

Macster

If you are referring to me as the "he" my responses convey much the same as yours.

I did offer that the piston maker should be able to offer guidance on what if any piston coatings could be used.

While I didn't spell it out at the time, this should come with guidelines regarding any changes to the piston's geometry or dimensions or feature locations, like piston ovality, clearances, ring positioning, etc.

The selection of piston coatings adds more complexity to an already complex process (correct and proper engine building) and I wonder for what benefit? You pretty much said the same thing, with your "keep it simple" and "slippery slope" comments.

You specifically noted that total timing may need to be reduced which then I suppose could require a custom tune. Since 996 engines with piston coatings are rare the tuner would be likely breaking new ground to get this right. This doesn't fall into the keep it simple category.

Furthermore, I note it is not like the stock engines are suffering unduly from the lack of proper piston (any internal engine part) coatings, unless the lack of piston coating has recently been added to the list of 996 engine failures.

I'd say even though I don't change my own oil (nowadays) my comments and advice was pretty much in agreement with your's.

Might add that during the time I was most actively involved in engine work engine coatings were a big topic. There was as I touched upon in a previous post the periodic appearance of the next big coating. Everyone was looking for *the* coating to work miracles: more power, better resistance to heat, less friction, lower emissions, better fuel economy or whatever.

Lower emissions and better fuel economy drove a lot of interest into engine coatings as my direct involvement in engines started at just about the time the first oil embargo hit the US/world and concurrent with a big push to lower auto emissions. Automakers would have sacrificed kittens to improve fuel economy and lower emissions so engine coatings were a hot topic.

And here it is decades later and still engine coatings on moving parts are primarily reserved for the very special needs of the competition community.

While I haven't followed the coating technology as well as I did I have yet to come across any large automaker using any coatings on moving parts. (There have been some big improvements in metallurgy, surface treatments, to improve internal engine part longevity.) With all the concern about better fuel economy and lower CO2 emissions (which determine the tax or fee each car is assigned and strongly impacts an automaker's bottom line) you would think if any coating out there would offer any benefit its use would be wide spread and touted as much as stop/start, 7/8/9 speed automatics and so on.

If the OP is interested, here's a link to a nice article that appeared in Hot Rod magazine that offers some test results of various coatings and the gains they provide:

http://www.hotrod.com/how-to/engine/...#__federated=1

While the article is circa 2008 IIRC I think generally the results would be the same today.

'course the OP is welcome to go the coating route and report his findings. This looks to be an expensive task though as the engine would have to be tested with and without the coatings. And then there is the question of engine longevity what benefit (if any) this has or does the presence of the coatings introduce another failure mode.

KrazyK

This is hilarious but I'm sure it wasn't aimed at you Mac. You always try to help.

But,, seriously, worrying about piston coating on a 320 (or less) HP M96 engine is laughable.

Schnell Gelb

Macaster - that is by far the best factual link I have seen - thank you.High rpm and forced induction seem to be the features that may indicate some value to the coatings for road cars.
Because it predates the "Abradable Powder Coatings" ,these newer products are not compared.
I'll concentrate on optimizing the lubrication system and oils.