Tech / General Engine Is your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Sponsored by:
Sponsored by: CARiD

rod bearing oil hole?

Thread Tools
 
Search this Thread
 
Old Jan 22, 2011 | 09:11 PM
  #1  
sand1303's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 66
Likes: 0
rod bearing oil hole?

ok so i am doing a budget build on my 350 i picked up to put in my 87 camaro. i am redoing the bearings but i am running into a problem(i think). my original rod bearings have a oil hole in them. all the parts stores are trying to give me bearings without any oil hole cut into it. is this normal that the oil hole is in some bearings and not others? my crank has oil holes in it where the rod bearings go. but is it necessary for the bearings themselves to have them? it is a gm 3970010 block. here is the bearing that came out of the engine
Attached Thumbnails rod bearing oil hole?-imag0091.jpg  
Reply
Old Jan 22, 2011 | 09:15 PM
  #2  
sand1303's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 66
Likes: 0
Re: rod bearing oil hole?

oh, another question. when putting the bearings in main and rod am i suppose to be putting assembly lube on both sides of the bearings or just the side that touches the crank itself.
Reply
Old Jan 22, 2011 | 09:23 PM
  #3  
Apeiron's Avatar
Moderator
 
Joined: Jan 2000
Posts: 20,981
Likes: 11
From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: rod bearing oil hole?

You don't need the hole. Lube only goes on the bearing side.
Reply
Old Jan 22, 2011 | 09:28 PM
  #4  
sand1303's Avatar
Thread Starter
Junior Member
 
Joined: Oct 2009
Posts: 66
Likes: 0
Re: rod bearing oil hole?

Originally Posted by Apeiron
You don't need the hole. Lube only goes on the bearing side.
this would be the inside?. leave the outside dry?
Reply
Old Jan 22, 2011 | 10:03 PM
  #5  
AlkyIROC's Avatar
Moderator
25 Year Member
Liked
 
Joined: Jul 1999
Posts: 17,271
Likes: 171
From: 51°N 114°W, 3500'
Car: 87 IROC L98
Engine: 588 Alcohol BBC
Transmission: Powerglide
Axle/Gears: Ford 9"/31 spline spool/4.86
Re: rod bearing oil hole?

The outside of the bearing doesn't spin in the rod. The inside of the bearing spins on the rod journal. The rod journal supplies oil to the bearing. Hole in bearing not required.

Assembly lube to the bearing side that touches the crank.
Reply
Old Jan 25, 2011 | 08:06 PM
  #6  
game1939's Avatar
Member
 
Joined: Feb 2010
Posts: 162
Likes: 1
From: savannah, ga
Car: 91 chevy camaro
Engine: 383
Transmission: 700r4 built with corvette servo
Axle/Gears: posi 3:73
Re: rod bearing oil hole?

dont forget to plastigage the mains and all for clearance or mike the crank....
Reply
Old Jan 26, 2011 | 06:36 AM
  #7  
sofakingdom's Avatar
Supreme Member
20 Year Member
Community Builder
iTrader: (1)
 
Joined: Sep 2005
Posts: 27,959
Likes: 2,469
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: rod bearing oil hole?

There is no oil hole in a rod bearing. No oil goes through the rod, therefore no hole is needed to let it pass through the bearing.

What the hole is, is for a "spit hole" to lube the cylinder walls. Some older engines (about 59 or earlier if memory serves) had this. There was a groove cut in the mating surfaces of the rod and cap, on the side without the tangs (facing the cam), and a hole to expose it was formed by a notch in the ends of the bearing. This provided a little squirt of oil up at the cyl on the opposite bank. At some point, GM decided it wasn't necessary, and quit doing that to rods. But some bearings still have it. Even some large-journal (67-up) bearings have it, although AFAIK no large-journal rods ever got that feature.

Bottom line, it doesn't matter; your engine didn't need it before, and doesn't need it now; and either having it or not will make no difference. Kind of like your appendix... yeah it's in there, but it doesn't do anything any more (if it ever did!) and doesn't matter oif it gets taken out.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
gixxer92
Engine/Drivetrain/Suspension Parts for Sale
5
Sep 1, 2015 04:32 PM
Navy8125
Engine/Drivetrain/Suspension Parts for Sale
4
Aug 21, 2015 09:32 AM
Dialed_In
Firebirds for Sale
2
Aug 20, 2015 01:45 PM
gwade12
Tech / General Engine
1
Aug 8, 2015 08:17 AM




All times are GMT -5. The time now is 07:28 AM.