Polishing engine internals?
 

Does polishing engine internals actually make a performance difference, or is it merely a cosmetic perk included when you get an engine ported/polished?

well i think it MIGHT make a small differnce because theres less fricton, but its not going to be night and day.

Dennis (Motorman) did mention before that the reason why the crankshaft and some parts of the engine internals are polished is to make the fuel stick to it:confused: I don't know why this is done but it is apparently good for performance... Dennis?

Like what NightLife, mentioned, the difference in performance will not be like night and day.

It depends on what yopu want to accomplish. Polishing will make the fuel stick so in some places it is good and some it is bad. I will give an example I resisted giving once before. I gave a theoretical reason but did not point at a particular part. I would and do polish the tunnel and outside of the crank on a turbo type crank, I would not polish the tunnel of a non turbo crank. Here is why!

on a turbo crank you want to get the greatest effect from the turbo cut. because the best way is to make the fuel stick to the outer wall. This in turn forces the fuel to follow the turbo cut path and it is centerfuged out of the crank under high force. This only works properly if the turbo cut is blended into the tunnel at the proper angle and is blended smooth.

On a non turbo crank polishing the tunnel would just slow down the flow out the crank and hurt low speed performance.

The comment I made before is that you have to evaluate what the hardware can do for you and envision the flow paths through the engine before deciding what to polish and what to not.

Air strakes along the bottom of the liner is something I invented several years ago. Many tuners use them now in some fashion or another either knowing or not knowing what there really putting them there for. Same goes for head jets. Head jets done wrong will really screw up the engines performance and they only work on some displacements of engines. A lot of thought went into the first RTU race engines.