Lurch519

Would putting a thermal barrier on the pistons keep combustion heat in the combustion chamber enough to make more HP or get better fuel economy ?

AlpineRAM

It will keep you pistons cooler while running at high hp and thus help you keep them from looking like that:

RustyJC

OUCH!!!

Rusty

HOHN

It's been my experience that the only drawback to most premium coatings is cost. If you can afford it, they are quite worthwhile, imo.

jlh

MDW

Been using coats for years.
http://www.polydyn.com/

Here's pics of one that I built using coatings.
http://www.hotroddiesels.com/images/engine-build/

Don M

With some luck I will get the pictures of my coated pistons posted today. I used Swain Technology for mine and it is not cheap like Justin said.

We had set of custom, 1 off pistons built and then sent them up to Swain back last fall and got the tops ceramic coated and the skirts Moly coated. This spring we re-designed the piston bowl, wrote a CNC milling program and milled the bowls a different shape. This required us to send the pistons back to Swain to be stripped and recoated. Finally I think we are happy with the bowl and the pistons are back from Swain. We were very happy with Swain. They did a great job. Unfortunantly one piston was damaged in shipping and it got a ring land beat up pretty good. They had to go back on the lathe to have the ring land cleaned up and finally to a grinder to have the ring land polished to a perfect surface finish3.

The lesson I learned was to wrap and double box each slug to keep them from getting even remotely close to each other in shipping and insure them to high value. I ate the 250 dollar bill to have the one piston repaired, but it was still cheaper than having another piston made and having it coated.

The total bill for coating the first time was around 275 dollars. The second bill was 230 to have the tops stripped and recoated. Between the pistons, the custom pins, the remilling of the bowl, the coatings twice and the damage repair...thesea re the most expensive pistons I have ever seen. Times 2

The coating is worth the money, IMO.

Don~

pmpislander

if you piston looks like that you had other problems not just high horsepower. you were starting to stick the piston, either from oiling issues or overheating the piston and pin. a coating isnt going to stop that from happening again. you need to find what the problem was and correct it. the coating is just going to prolong the galling of the cylinder walls and piston by a couple of strokes untill the coating is flaked off and then not only did you ruin the cylinder walls and piston but you now have flakes of the coating running through your engine and damaging other parts if not just clogging up you oil filter.

Don M

Here is a few shots and one shot of the coating on the pistons.

http://www.f1diesel.com/pistons.html


Don~

RedRotors

Ive been personally at the Swain shop ( 9h drive from here ), they are real pro and
their shop is awesome.. Here what it looks like. ok this is a tiny vw tdi piston but this
is pretty the same.. Top coated with TBC and the skirt with polymoly.



Marc/

AlpineRAM

The thermal barrier coating is a help against too high piston temps- one of the main causes for galling the piston. Naturally oil cooling etc must work, but IMHO the coating will help a good bit when you are on the ragged edge of what the engine will stand.

Moly or PTFE coating of the skirt will behave as you predicted in a situation when the cooling of the piston won't work. But the thermal barrier coating will help in keeping piston temps down, and the skirt coating will help reduce the friction on startup and while still cold.

The piston on this pic had it's good share of abuse, no coating would have prevented that.
(But IMHO a good pic of what happens to a piston wiht a too high crown temp)

AlpineRAM

HOHN

What, no pic without the Snidely Whiplash treatment? hehehehe

Lurch519

Thanks for the input gentlemen. Looking for ways to make an engine to put every last bit of power to the ground from every bit of fuel going into the little bugger. I figure it will take awhile to gather all the parts, but I've got time. Thanks again

gunracer1

hey don, some moron but a big black box where you super secret bowl design should be.

Bart Timothy

"drawson", over on the TDR had his pistons coated after huffing a turbo on Edge's dyno 2 years ago, which required an engine rebuild. Said he wasn't sure whether he'd do it again. Something about the engine running too cold at idle, and the high cost of it all vs. benifits, if I'm remembering right.

Lurch519

That is allot of what I was wondering. Would the coating keep enough heat off the piston crown and in the combustion chamber to reduce the need for as much engine cooling, and would the extra heat produce enough energy to get a measureable increase in power and/or fuel economy.