Originally Posted by hcompton
You polish the pistons with a bench grinder that has longer shafts for a large polishing cloth wheel. Heads can be done with a diegrinder/dremel but it will take forever.
Polishing on the street is not needed. But is not effected by carbon for two reasons. One the carbon does not stick to the polished surfaces, two the polished surface still reflects heat even if it cant be seen. This is way home insulation has reflective foil backing and is never going to see any light because its buried in the ceiling and under the roof of the house but still reflects heat back into the house.
This will help on any engine street or race but usally time consuming and if your not doing the work your self you will have to pay way to much to have it done. If you got the time it doesnt hurt.
Only forged pistons can be machined with little impact on the strength. This is only becasue they are way stronger than most apps can use. But if they are borderline in strength and they are cut they will fail for sure. Also cutting the piston head tends to allow the head to collapse and expand at different rates from heat and casues issues that buying pistons cast in the correct shape is always the way to go.
Hyper, and cast iron pistons can not be but they will fail. They are sometimes cut to reduce compression but this is done to engines that make 200hp not 500. So once you think about your goals and you will be buying the correct pistons and go no need to cut them at all.
I'm getting a bit tired of correcting you. Have you ever even opened up an engine?? There is carbon almost the second you start the engine the first time- polishing chambers is a total waste of time for him.
Maybe you don't believe me- but how about Larry Freaking Widmer
It does NOT take "forever" to use sanding rolls, etc. to do the chambers w/a die grinder- that's how it's done by everyone who does this!
Son, I have hand machined cast
pistons to work w/a set of Trick Flow Twisted Wedge heads to work w/a 0.640" lift solid roller that we ran on nitrous, I hogged the HELL outta those pistons- guess what? No failures of the pistons. Period. Do I recommend it? Of course not- that's why I added the comment above. But it's not like it cannot be done as easily as it can w/forged pistons. What do you think was done in the early days of turbocharging, before there were "turbo" pistons?
I have the distinct feeling you're shooting totally from the hip and have no actual
experience w/ANY of this.