Piston Paint

[Thesandman]

Has anyone used the hi temp reflective paint so popular with 4 stroke builders? Piston dome and combustion chamber cylinder head.

 

[Thesandman]

No one knows anything regarding this?

 

[Loony661]

Give it some time bud - it’s the weekend and everyone is likely out and about. I’m sure someone can shed some light on the subject sooner or later.

 

[Thesandman]

Thanks Loony

 

[B440]

I always thought heat rejection through the cylinder head was a good thing since that's where the fins or water jacket was, and reflective coatings were for the piston? My initial thought is paint disappears with the high temps seen in the cylinder and only coatings like ceramic hold up. Anyway, listening in to see if anyone knows about paint internal to the cylinder.

 

[Thesandman]

Thanks B440; I think they are still called paint do to application methods. A cooler cylinder means higher power. When I removed my cylinder I found cooked mixture in transfers only adjacent to ex port

 

[Loony661]

A cooler cylinder means higher power.

It’s more about keeping the heat inside the combustion chamber. The combustion chamber needs to remain hot enough to keep fuel atomized/vaporize and burn completely. Too cool and the fuel won’t burn completely and power will be “lost” as the engine is literally spitting out unburned fuel. Think of when the saw is started cold and it’s smoking - as the saw reaches operating temperature, it no longer smokes because the fuel particulates are being burned, not ejected out the exhaust.. Coatings try to help keep heat where it is needed, in the chamber, instead of being absorbed by the surrounding metal. That’s why heat reflective coatings are used in the cylinder head and on the piston top.

 

[Thesandman]

I read a article from India on small single cylinder 2 stroke engines that showed over 20%hp increases everywhere except full pwr which showed almost that amount of loss due to heat. Coating made high temps right at coating surface much like detonation does. Maybe just do piston dome and exhaust tract. I was hoping for some first hand experience. Thanks

 

[Stevetheboatguy]

https://swaintech.com/

Only coating I would trust.


Steven

 

[Ketchup]

I have minimal experience with LRB and Wiseco “performance” coated pistons. Neither lasts very long and looks awful when you peak through the exhaust port. I think there is merit in a good performance coating but the application process is beyond the reasonable price point of a work saw. Self application products probably aren’t worth the effort.

There are some ceramic epoxies out there that could potentially be used in ports or the dome. I haven’t messed with it.

 

[Stump Shot]

I read a article from India on small single cylinder 2 stroke engines that showed over 20%hp increases everywhere except full pwr which showed almost that amount of loss due to heat.

Possible the answer lies here, seeing that chainsaws are used primarily at full pwr.

 

[farminkarman]

Any piston dome coatings I'm aware of are some flavor of anodizing. It would be news to me that there is a paint for this.