rod bearing confusion
#1198366
03/17/12 01:22 PM
03/17/12 01:22 PM
|
Joined: Oct 2009
Posts: 92
south carolina U.S.
DOUGG
OP
member
|
OP
member
Joined: Oct 2009
Posts: 92
south carolina U.S.
|
maybe I'm missing something but all the rod bearings I'm looking at for b/rb engines don't have the oil hole/groove to match the groove on parting line of the rod/cap. Isn't that supposed to spray oil on the opposit cylinder wall ?
[
|
|
|
Re: rod bearing confusion
[Re: DOUGG]
#1198367
03/17/12 01:28 PM
03/17/12 01:28 PM
|
Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
1_WILD_RT
Management Trainee
|
Management Trainee
Joined: Jan 2004
Posts: 27,347
Today? Who Knows?
|
It has been found unnecessary & eliminated....
"The Armies of our ancestors were lucky, in that they were not trailed by a second army of pencil pushers."
|
|
|
Re: rod bearing confusion
[Re: Cab_Burge]
#1198370
03/18/12 12:07 AM
03/18/12 12:07 AM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
In that case I'd sure want to add em
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: rod bearing confusion
[Re: RapidRobert]
#1198371
03/18/12 09:55 AM
03/18/12 09:55 AM
|
Joined: Oct 2009
Posts: 92
south carolina U.S.
DOUGG
OP
member
|
OP
member
Joined: Oct 2009
Posts: 92
south carolina U.S.
|
more comfusion. the mopar perf. engine book says that if the rods are oriented correctly the groove will put oil on the opposit cyl. wall, but, if one of it's purposes is to help lube the cam, could be a reason why we have so many cam failures ? most of us tend to "push" our engines & maybe other sources for cam lubing can't keep up
[
|
|
|
Re: rod bearing confusion
[Re: dogdays]
#1198373
03/18/12 10:21 AM
03/18/12 10:21 AM
|
Joined: Jan 2003
Posts: 25,200
Upper Midwest
MoparforLife
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
|
Quote:
These grooves have been there since the beginning of the automotive age, it seems, and they have always been there to oil the cylinder walls. It is wishful thinking to think that they are for oiling the camshaft. They don't aim at it, either. Most camshaft oiling has been by splash, with oil getting past the lifters and some from the valley supplementing.
When you're building an emissions controlled engine you want to keep as much oil out of the combustion chamber as you can. It seems that there is enough oil mist in the crankcase to oil the cylinder walls without those extra squirts from the rods. The use of lower-tension rings to reduce friction also makes extra oil on the cylinder walls bothersome.
This explains the general trend away from these grooves.
For the high performance engine, extra oil in the combustion chamber can cause knock, as oil has a much lower octane rating than gasoline.
R.
 
|
|
|
Re: rod bearing confusion
[Re: dogdays]
#1198374
03/18/12 07:24 PM
03/18/12 07:24 PM
|
Joined: Aug 2003
Posts: 43,157
Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,157
Bend,OR USA
|
Quote:
These grooves have been there since the beginning of the automotive age, it seems, and they have always been there to oil the cylinder walls. It is wishful thinking to think that they are for oiling the camshaft. They don't aim at it, either. Most camshaft oiling has been by splash, with oil getting past the lifters and some from the valley supplementing.
When you're building an emissions controlled engine you want to keep as much oil out of the combustion chamber as you can. It seems that there is enough oil mist in the crankcase to oil the cylinder walls without those extra squirts from the rods. The use of lower-tension rings to reduce friction also makes extra oil on the cylinder walls bothersome.
This explains the general trend away from these grooves.
For the high performance engine, extra oil in the combustion chamber can cause knock, as oil has a much lower octane rating than gasoline.
R.
Lets see, inline four and six cylinders don't have them,V6, V8,V12 and non OHV V12 have them   Another thing to consider is that the standard V8 rod bearings do not have oil pressure for 360 degrees of crankshaft travel with single groove main bearings, so the oil pressure is not there to squirt oil into the cylinders at all times  Most commercial turbocharged motors, diesel and gasoline, have piston oilers installed in those motors to squirt oil into the bottom of the piston domes to cool them
Last edited by Cab_Burge; 03/18/12 07:27 PM.
|
|
|
|
|
