Coatings are a thermal barrier and polishing is not. That would be the reason to do one vs the other.
Thermal barrier to prevent what? Oil baking on the bottom side? I have seen people run these both with a top coat and without. I havent found any feedback or benefit relating to coaitng the tops? Thanks for the response!
In theory the coating helps the piston withstand higher egt's.
In theory the coating helps the piston withstand higher egt's.
There are really good coatings out there but not available to the general public. NASA used these on the space shuttles to prevent meltdown on reentry in the atmosphere. I wish it was available for purchase somewhere. I had iron my original set of pistons but that source closed their doors.I don't know how much better they are as some have still melted/ burnt the coating off but I suppose it's better than nothing.
They are available to the public. It's just that nobody has 50k laying around to spray a set of pistons. I joked around with a NASA engineer a few months ago about spraying some pistons for me. (We are working on new injectors/rocket engines for them, all of which are sprayed with exotic materials which I then machine) he said sure give them to me when you ship us the liners for spraying lol.
Ummm, if you need coating on them to stay alive you are doing something wrong in the way you are making hp. Brett's pistons are not coated and barely polished and look like new everytime the heads were off.:thumb: