The Ford Barn

EZDriver · 04-05-2018, 12:54 PM

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

Jim Brierley · 04-05-2018, 04:51 PM

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.

Mark in MT · 04-05-2018, 06:42 PM

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.

Tom Wesenberg · 04-05-2018, 07:05 PM

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

04-05-2018, 12:54 PM	#1
EZDriver Junior Member Join Date: Jan 2016 Location: Holly Lake Ranch, Texas Posts: 4	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 Last edited by EZDriver; 04-05-2018 at 12:55 PM. Reason: grammer

04-05-2018, 04:51 PM	#2
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,089	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.

04-05-2018, 06:42 PM	#3
Mark in MT Senior Member Join Date: May 2010 Location: Western MT Posts: 218	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. __________________ Mark in MT Always looking for another opportunity to be wrong.

04-05-2018, 07:05 PM	#4
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: Main and Rod bearing oil groves Sponsored Links (Register now to hide all advertisements) It might look too small because the babbit is worn away. First thing to do is check the clearance and adjust as needed.