Shot Peening Con Rods \ Teflon/ceramic coating pistons

[torqued]

Does anyone have any Cons / Pros thoughts on the subject?
Any alternatives (bar forges) ? or advice?

[chris_g1]

Shot peening is great gives a lot of extra strength its good to take all the casting marks off the rods also as for coating the pistons not to keen as ive had them seize after doing it . I would make them fully flouting though that adds a lot of extra reliability

[R30_Elliott]

Depends on the circumstances, I had this discussion recently with my engine builder,
Shot peening is good , but you should anneal and balance the rods after, which starts to add up but definitely is worthwhile doing
Teflon coating is apparently good if you're running a high strung NA engine trying to milk the last couple of hp out of it, but if the teflon un bonds from the piston its super abrasive as it's so hard and can cause huge damage to bores and valvetrains. Can also cause funny heating, where the piston/head used to absorb some of the heat and dissipate it the teflon blocks this and the heat ends up in your bores- which could cause seizing.
I decided to stay away from it and any hp I don't get by not coating them will be made up for with more boosty.

That's only One builders opinion and the info I've found from doing a bit of internet digging, no doubt other's will have positive experiences with it

[Bartman]

I have both shot peened conrods, and ceramic thermal barrier coated piston crowns, and dry film lubricated skirts.

Shot peening is the last step in your rod prep.
Polish the beams smooth with a finger linisher. Then fit ARP rod bolts. Then have the rods resized. Then balanced. And finally shot peened. It compresses the top layer of the metal, and stress relives them. The polishing removes stress risers, and places where a crack might start.

As for the pistons, I think it's a good thing. Just have your block bored/honed after they're coated so that you still maintain the right clearance, as the coating will increase the dia of the piston ever so slightly.
You can also get an oil shedding coating for the underside of the piston. Stops the oil sticking, so reduce windage, and I presume carry the heat away faster?