Internal engine coatings?

The return on investment won't be too good for thermal coating piston crowns,
chambers,etc. as stated above.Yes they DO what they say,but the improvement may
not be noticeable depending on the application. I'm always for improving efficiency &
power output,but there are plenty of more effective per dollar choices in line ahead of
these coatings. I would however recommend the coatings inside and out on exhaust
manifolds,drops underhood temps some,and they will look great for a long time on a
mostly fair weather machine.A customer had the HP mannys on his 440 6-pak 'cuda
done I believe around 20yrs. ago, and they still look great,just don't get them wet
when they're hot.They tend to stain or discolor if you do.