Interesting things I found out with the engine apart ..

Thought the crosshatch is only for run in periods and after that it wears out with time ?? .. 1st time I see it on a hi-performance engine though .. I know hondas doesn't have these .. or at least by the time I took it apart





Any suggestions on what to do to the head ??

 

Honda has it too... mine (GSR) still had faint lines at 100k.

Looks like exhaust valve was getting a little cooked... or it's just the picture.

 

How many miles on that motor? I just bought a head and block from Nastea that has 20K miles on it. It's still got the crosshatching exactly like yours.

 

Zeus, it's the fotoes
Yub.. they are a little cooked form the looks of it .. actually .. I had the B16 engine apart at 40k .. and the crosshatch were already faint outlines .. not like these .. you can even feel the 'roughness'

Prop.. I have like around 30k on this engine ..

 

The crosshatch is supposed to stay, the friable materail, or the high spots will wear down over time, but a visible cross hatch help to hold oil on the walls even as the rings slide past. High mileage, hard use, and normal wear may show some areas where the hatch is worn, due to a variety of factors, such as skirt contact or the area where the ring package stops and changes direction, but for the most part, you will still see craosshatch on 100k plus walls no problem. But that doesnt mean that at a rebuild you dont lick the cylinders with a set of plateau hone stones to give a fresh surface for the rings to break in on.

 

In dealing with the Yamaha V6 in Taurus SHOs, what we realized is that unlike the typical American V8s, the metallurgy is such that the crosshatch in the bore stays crisp even after 100k miles. Instead, it is the piston rings that take the brunt of the wear, and it is these that will eventually require replacement while the bore finish remains sharp.