Piston Coatings

[Anonymous]

Looking for anyones opinion,

: Do you think the coating that is used on the skirts of performance pistons has any value on the street?

I have seen people buy products that allow them to coat the skirts and then cure them in an oven. : Will this last or will it come off?

: I have heard that using a low friction coating will free as much as 10 to 20 hp. Do you think this is correct?

Just trying to find the truth through all the BS, thanks.

John

 

[rbohm]

8) use the same coating the top fuel racers use. it is the best. as long as the coating is applied properly it is durable. as for the amount of power increase, that depends on the engine. our little sixes might pick up 10 hp max, though likely closer to 5hp. the real benefit though is if oil pressure is lost it will help prevent the pistons siezing against the cyl walls.

 

[J.R.]

A primary wholesale/retail supplier of several of the coatings is TechLine Coatings in Texas. http://www.techlinecoatings.com I'm about ready to order up an assortment of their stuff.

J.R.

 

[Anlushac11]

8)

As mentioned the coating if applied properly is very duarable. Any reduction in friction will help toward the whole of making more power.

The quote of 30hp jsut for coating pistons is misleading.

Iif you build an entire engine using coatings for allt he applicable parts such as thermal barriers, oil shedders, dry film lubricants, etc. The sum of all the coatings helping on the whole engine can net as much as 30hp jsut for coatings, but for one part or group of parts seems a bit high.

 

[Anonymous]

On the site www.dieselinjection.net/articles.htm they talk about using ceramic coated piston heads with teflon coated skirts. I figure if this works and holds up in a Cummins making nearly 900hp, then it should hold up in a 400hp 300-6TT. I am trying to get in contact with the company about doing a set for me. What is the opinion on this?

Jared

 

[J.R.]

Latest word I heard was positive on the Zr-ceramic heat barrier coatings for piston tops, but that Molybdenum Disulfide was a better way to treat the piston skirts(& cylinder walls, after final hone). Heat barrier coating also works on the combustion chambers, valve faces, entire exhaust port, and even the exhaust manifold interior, if the engine runs a turbo. I've heard mixed results on the teflon, even comments that it can peel off & get chunks stuck in the oil pickup system. Personally, I'm going to go with the Moly for pistons & cylinders, maybe cam & crank journals, too. Beside, I can apply that & the heat barrier at my home shop, but not the teflon.

J.R.

 

[addo]

I am a little reserved about the ability of any film type coating to last as long in service as normal, uncoated engine parts. In other words, it will come off or wear off somehow. What it does then is really the issue to be concerned with.

I've used a lot of high spec teflon coated router and saw bits, and sometimes, the coating has flaked. If this happens on your motor, could be a problem.

Just my 2¢, anyway.

Cheers, Adam.

 

[rbohm]

8) the coating on the piston tops is called hienium. it is a metalic/ceramic coating that is plasma sprayed on. the coating is very strong except for the edges which are delicate. that is overcome easily by machining the top of the piston to the depth of the coating and leaving a lip, thus no edge. i first learned of this coating in college. the demonstration used a torch to heat the piston top untill it was glowing red, at that point the demonstrator, using bare hands, picked up the piston and put his thumb on the backside. he never got burned.

 

[Anonymous]

We had some NASA folks up at our school when I was a kid. I was the kid they picked out of the crowd to go up on the stage and hold a 6"x8" (or so, it was a while ago) chunk of the tiles they put on the outside of spaceships while they hit it with a blowtorch. Made an impression on me in any case.

As for teflon, Dupont says not to put it in your motor, and being as its their product i'd tend to believe them.

For cylinder coatings, is chrome used anymore? I know with R/C nitro motors they use ABC (aluminum, brass, chrome). The cylinders are chromed out and they seem to do well by it (32,000rpm .21cid 2.7hp on 30% nitro fuel).


-=Whittey=-