I noticed that the crank does not have a hole in it on the middle main journal. The only oil passage is on the main cap. The rest of the main journals have holes in the crank and cap.

Why is this? It just so happens that the motor I am rebuilding has the most damage on that one journal.

 

anyone?

 

bump for a good Q.

 

 

hrmm, interesting question. There has to be a logical reason though, I never noticed that....

 

Is the H22 one the same way? This is an H23.

 

The lubrication comes from the mains therefor it is not needed. The other passages are lubrication from the mains going to the rods.

 

It is interesting that the #1 and #5 journals are drilled, but #3 is not. Maybe the benefit of extra strength at the center of the crank outweighed the cost of redundant oiling. For instance, the #1 and #2 rods are fed from the #2 main journal, so drilling the #1 journal seems redundant, but it gets drilled. Anyway, if you are not following this, it's like 2point6 said: The holes are to get oil to the rods.