1974 XS/TX650 rebuild

[hemmjo]

Polishing internal parts is much more than just visual obsession. It has profound effect on performance. When done properly it also makes parts stronger. This may be counter intuitive, since material is removed during the process. However, by removing surface imperfections, you also remove places where fatigue cracks can begin to form.

For reference, try to break a piece of glass, then scratch one just like it and notice how much easier it is to break. It also enhances oil flow. There is some research however to indicate that polished intake runners in carbureted engines can cause fuel to condense rather the stay atomized in the intake stream. I do not have enough information to say ya or nay on that..

Many connecting rods and other parts in modern high performance and race engines are aluminum, or titanium, forged or CNC machined from a forged billet, then polished in Giant Finishing Machines. Back in the day, us poor unfunded hot rodders would polish stock rods and other parts by hand to make them stronger.

We even polished entire engine blocks, cylinder head, rocker arm surfaces, etc to allow oil to flow more freely back into the oil pan. At high RPM it is possible to pump all of the oil out of the pan because it pumps out faster than it can drain back down.

Giant Finishing, has a whole series of videos on youtube about vibratory finishing. If you are interested, put Giant Finishing Episodes in the YouTube search bar. Then click VIEW ALL EPISODES. This will show you the whole list.

Two videos specifically related to this topic are;

66 Giant Finishing - How To - Finish Connecting Rods - Part 1 and 67 Giant Finishing - How To - Finish Connecting Rods - Part 2

There are many other videos of cylinder heads, crankshafts, valves, headers, etc.

After a while they get a bit repetitive, but at least for the 66 and 67, be sure you have the sound turned on and watch at normal speed. I won't tell you why, you can be surprised. Being pleased or not, will depend on your age