No downside
I read your treatise of what's required for minor improvements and I almost totally agree.
Here's a performance increase with no downside--it's low cost and makes whatever part is coated last longer but the thing that should interest you most is that it reduces friction.
I coat EVERY part inside the pump cavity including the outside edges of the vanes and the pivot pin--very time consuming--but most of the benefit could be attained if just both sides of the pump body and the "wall" were coated with antifriction. This is the same material used on piston skirts. BTW--I dropped off a crank to be balanced yesterday and the techie told me that coatings has been outlawed in the classes they build motors for--he asked about the the coated piston heads and skirts.
I have no way to accurately measure performance/efficiency improvements but I can tell you that my gas mileage went up 1.5 mpg when I switched from a normally rebuilt 200 4R to one that was fully coated. This is highway driving with the convertor locked most of the time with no other changes and the mileage increase was from 20.4 mpg to 21.9 mpg mileage corrected using highway signs and trying to maintain the same vaccum and speed over a 250 mile distance that I often drive--almost all Interstate. I used this for years to tune the cruise settings on my Q-Jet.
What do you think?
I do agree with your theroy though!
