Main and Rod bearing oil groves
 

Hello One and All,

Haven't posted for a while.

I have been concerned about the fact that I think my center main in my 1929 Special Coupe might have too much tolerance and is knocking. Have removed the center main cap and found the oil groove to be what I think is too small. Can anyone give me the dimensions for the grooves that are cut in the bearing surface how deep and how wide they should be. The engine was overhauled back in the 60s and has been driven very little ever sense. I want to drive in more from now on I am not sure how much I should refurbish. Any help would be greatly appreciated.

EZDriver

Re: Main and Rod bearing oil groves
 

Size of the grooves makes little difference as long as they are in there. Normal width and depth are about 1/8". Some are machined into the babbitt after it is poured and machined to size, some are cast in as the babbitt metal is poured into place. The grooves should not continue to the end of the babbitt as oil needs to stay in the bearing. not run right back into the pan.

Re: Main and Rod bearing oil groves
 

According to the ford prints, the grooves are 3/32 to 7/64 wide, sides forming a 90 degree included angle, with a 1/32 radius in the bottom. The rod print calls out the depth to be 1/32". Like Jim says, it ain't magic, the oil will find its way.

Re: Main and Rod bearing oil groves
 

It might look too small because the babbit is worn away. First thing to do is check the clearance and adjust as needed.