OEM's coating engine internals?

[Curious Kid]

I am curious if any engine manufacturers are utilizing thermal barrier coatings for piston faces, cylinder head domes and/or valve surfaces? I do understand there can be NOx issues due to maintaining heat within the combustion chamber gasses which go towards maintaining a higher temperature average, but would the gains of maintaining higher combustion pressures and lower energy transfer to the coolant, etc., out way this? I suppose initial costs and a question of reliability (de-lamination) stand against said benefit(s). I have heard around here that side skirt treatments have been utilized for friction reduction (moly type coating), and have even seen pics of pistons that have supposably been in service for some 500kms (or was that 700kms?), and it still looked as though much of the coating was still present and un-scared. Also, just how are NOx limitations based, average engine output? Thanks in advance.

 

[jamesn]

i have read that ferrari/maserati use piston and combustion chamber ceramic based coatings heavily. many motorcycle engines use a piston skirt coating. BMW and porsche used to use nikasil on their engines. now they have a silicon carbide cast into the cylinder liners themselves. this keeps them from breaking down in the presence of high sulfur fuels.

 

[TurboJim]

Do racing engines, such as those used in NASCAR, use thermal coated parts in their engines? If so are they using ceramics, PFTE, or some other substance?

 

[BarkerMan]

Ceramics are used inside racing engine along with other special coating. I don't think you will get much information because it's not a subject of idle conversation. Gaining experience is expensive and many of the engine developers just don't talk about it. Some of these ideas are making it into cheaper forms of racing and into street performance engines. I think Audi has a big program going on with coatings and alternate materials. We should see if we can get RI_RS4 to respond about Audi developments. His comments would be interesting. RI_RS4 are you out there?

 

[NYEngineer]

I've built two engines using heat barrier coatings on piston tops, valve faces and combustion chambers. Also a dry film lubricant on the piston skirts and valve stems and on the valvesprings to shed hot oil more quickly. One engine was a straight up rebuild, same cam, pistons, etc... It revved a couple hundred RPM higher and did get slightly better mileage. The big block had no visible wear when I took it apart later on, when usually it looked beaten. Actually, both of these engines were in older, exempt cars, so I cannot accurately answer your question about emissions, but I will be installing a fresh engine in my Yukon next summer and this engine will also be coated. I'll know then.

 

[Kestas]

I know the japanese were looking into thermal barrier coatings on pistons 25 years ago. The japanese federal goverment alloted a good chunk of money for that research, unlike the US auto companies, who need to fend for themselves for any technological improvement. The idea was that thermal barriers would resist heat loss, making the engine more efficient. This was considered for the public good, thus the reason why government funded the research and not the individual auto companies.

 

[dailydriver]

There were more than a few articles about this very topic in "Racecar Engineering" magazine over the last few years. You could see if they have an archive for past articles?

 

[biomed_eng_2000]

Have you sen this cool process? http://www.mikronite.com/testData.asp

 

[jamesn]

spoke with a friend today who races 2 stroke motorcycles. the pistons, valves, rods, combustion chamber and exhaust ports on his racing engines are all coated. on a 250cc engine they are only worth about 3 hp but he claims almost twice the lifespan compared to the non coated engines. he said they also run about 30-40 degrees cooler.

 

[cmhj]

We used a coating process with a couple of our drag sleds in the early 90s with readable results. Also, life expectancy was increased.

 

[Gary Allan]

 Quote:

I've built two engines using heat barrier coatings on piston tops, valve faces and combustion chambers. Also a dry film lubricant on the piston skirts and valve stems and on the valvesprings to shed hot oil more quickly. One engine was a straight up rebuild, same cam, pistons, etc...

My buddy did this on a couple of engines he built for his customers. Air brush and an oven. It' retains the heat in the combustion chamber instead of shunting it through the piston or the water jacket. It makes a few more HP.

 

[Kestas]

Mikronite appears to be a process that combines shot peening and polishing in one step. It merits consideration.

 

[Doug Hillary]

Hi, Porsche (and others - BMW,MB etc) have long used special liners or block (AluSil for example) structures that preclude the need for additional "coatings". The wearing surface is actually the silicon particles used at a very high "exposed surface" rate Many of these blocks/liners are nearing (some have exceeded) the 1m kms barrier Porsche have used Piston coatings on their aluminium pistons for some decades. Typically they were/are chrome (Mahle) and iron (KolbenSchimdt). There are others too Regards Doug

 

[ShiningArcanine]

 Originally Posted By: Kestas

I know the japanese were looking into thermal barrier coatings on pistons 25 years ago. The japanese federal goverment alloted a good chunk of money for that research, unlike the US auto companies, who need to fend for themselves for any technological improvement. The idea was that thermal barriers would resist heat loss, making the engine more efficient. This was considered for the public good, thus the reason why government funded the research and not the individual auto companies.

The Japanese have a mountain of debt and they can never stop spending. They are worst than the US Congress, with their public debt equaling 177.60% of their GDP, versus 64.70% for the US. I do not know about you, but I do not want the US public debt to equal Japan's. Also, if US automobile companies had to fend for themselves, they would have gone out of business a long time ago. For example, Chrysler received a loan from the federal government in 1980 while AMC did not receive any such loan. I need not remind you of the outcome of that situation.

 

[Steve S]

Didn't Chrysler buyout AMC?

 

[Kestas]

Chrysler paid off the loan, and this loan did not cost the government one cent. The loan did not come from government, the government only guaranteed (cosigned) on the loans made to Chrysler from the banks. But I agree, without the government's help, Chrysler couldn't have done it alone.

 

[TurboJim]

I believe ceramics will be the PFTE of the future. Maketed in anything and everything. We're already seeing this in high temperature paints / sealants and brake pad compositions. I did a Internet search for ceramic oil additives and came up with a half dozen or so products. Not all are marketed in the U.S. and some that are might just be relabeled items sold in other markets judging from their packaging.

 

[gtx510]

http://www.swaintech.com/ owner was GM's coating engineer http://www.calicocoatings.com/ newer company http://www.techlinecoatings.com/ diy and professional coatings

 

[Shannow]

 Originally Posted By: TurboJim

I believe ceramics will be the PFTE of the future. Maketed in anything and everything.

Ceramics have been cutting edge for ages. Ford had a plastic/ceramic "adiabatic" engine in the early 80s that was going to revolutionise the motoring industry. We put a bucket load of ceramics into a water tube boiler in 95/96/97, and they have shown zero wear while we've replaced 3/8 tube adjacent to them.

 

[TurboJim]

Racing engine coatings in the news - http://nascar.speedtv.com/article/cup-many-to-start-from-back-of-the-pack/