Kozmo
Forum Newbie
Posts: 26
Age: 66
Loc: pahrump nv
Reg: 01-25-11
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02-16-11 10:29 AM - Post#2047445
I have a 70-72 350 block. 2-4 the cam bearing holes line up with the main saddle holes. the #1 cam bearing lines up with the oil hole in the block. In the picture shows the present position of my #5 cam bearing and DOESEN'T line up with any hole. Threre is a hole in the gally that goes to the bearing but is blocked by the back of the bearing. Question- should the cam bearing hole aline with the oil gally hole?
Is the bearing spun in the picture and thats why my oil pressure to the top end was cut off.
http://www.flickr.com/photos/kozwood/545074 6799/
I know we have gone over this, but there are different positions for different yr blocks and I need to get this right. Please answer yes or no, then any advise or comments would be greatly welcome. I don't mean to sound like a butthead but these days confusetion comes easy.
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 grumpyvette
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17774
Age: 75
Loc: farmersville texas USA
Reg: 03-16-01
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02-16-11 11:01 AM - Post#2047455
In response to Kozmo
you need to clean out the oil passages and replace the cam bearings
first PULL ALL THE OLD CAM bearings and INSTALL new ones so you can remove crud trapped behind them
and rod out all the oil passages.
instructions in links below as to oil hole clocking
theres a GROOVE under the cam bearing so oil will enter at any location PROVIDED you get it installed correctly front to back so the oil feed holes line up with the groove under the bearing BUT look at this, you will want to support the cam with maximum oil wedge under the cam bearings, remember the bearings are NOT interchangeable in all locations
http://forum.grumpysperformance.com/viewtopic.php?...
http://forum.grumpysperformance.com/viewtopic.php?...
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!! |
Edited by grumpyvette on 02-16-11 11:10 AM. Reason for edit: No reason given.
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Kozmo
Forum Newbie
Posts: 26
Age: 66
Loc: pahrump nv
Reg: 01-25-11
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02-16-11 11:20 AM - Post#2047467
In response to grumpyvette
so no matter what yr the block,the 2 o'clock position is the best. That goes for all 5 bearings?
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motorman
Dedicated Enthusiast
Posts: 5189
Loc: south western pa.
Reg: 01-25-00
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02-16-11 11:39 AM - Post#2047474
In response to Kozmo
so no matter what yr the block,the 2 o'clock position is the best. That goes for all 5 bearings?
with cam bearings having .004+ clearance you will have a internal oil leak around the cam bearing and cam bearing journal if you put the oil hole at 2 o'clock. put the oil hole at 4 o'clock as this will put the oil at the highest loaded area between 5 and 7 o'clock because of the rotation of the cam. i know bow tie blocks have the oil hole at the 2 o'clock position but most of theses blocks use needle bearing cams. the GM power manuals recommends that the cam bearing oil hole be placed at 4 o'clock with plain cam bearings
| retired race engine builder,former NASCAR tech inspector. new corvettes owned 1959,1962,1963,1964,1965, 1966,1997,1999,2002,2005, 2008 plus 30+ other chevy cars and trucks along the way. 2008 corvette sold and waiting on a C-7. |
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fritz1990
Dedicated Member
Posts: 6576
Age: 61
Loc: Kansas
Reg: 02-16-03
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02-16-11 12:20 PM - Post#2047495
In response to motorman
With the block in the upright position i.e. like it sits in the car.
Regards, Jeff
1998 K1500 6.5 Coal burner
1965 C10 with 498 BBC AFR Heads
1964 C10 Ran 348W for 6 years, now SBC.
Corvettes owned: '74 '77 '78 L82 Silver Anniversary, 2002 LS1, 2007 C6 Love this one! Now have 2014 C7
Don't have a nervous come together!
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Kozmo
Forum Newbie
Posts: 26
Age: 66
Loc: pahrump nv
Reg: 01-25-11
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02-16-11 01:44 PM - Post#2047525
In response to fritz1990
Found this to add to my confusetion:
July 2002
TB 1996
Optimum Placement Of Camshaft Bearing
Oil Feed Hole Location
The AERA Technical Committee offers the following important information on
optimum placement of camshaft bearing oil feed hole location during installation.
This information should be considered any time camshaft bearing replacement is
being done.
Maximum camshaft support will be realized by installing the cam bearing oil feed
hole to the optimum clock location. Blocks and heads using a 360° oil groove
located behind the bearing oil feed, allow one to move the clock position of the cam
bearing oil feed hole. This way you can adjust the clock position during cam
bearing installation to make sure that the optimum location for the best
hydrodynamic wedge is selected. Locating and installing the cam bearing to take
advantage of this hydrodynamic wedge will supply the maximum support for the
camshaft during engine operation. The direction of camshaft rotation and the
engine oil entry point into the bearing control the placement of the hydrodynamic
wedge.
Note: If the oil feed passage in the block or head is just a hole without a 360°
groove, the bearing oil hole must line up with the oil feed passage in the block or
head. In some instances, the bearing oil feed hole in the cam bearing also lines up
with a groove cut in the camshaft journal. In those instances, the location of the
bearing oil feed hole in the bearing is also very critical fore and aft and may not
match up 100% with the hole in the block or head.
The illustration in Figure 1 below shows the optimum engine oil feed hole location
for a camshaft that is turning clockwise as viewed from the front of the engine.
Note: If the camshaft being used is driven with a gear-to-gear arrangement, or is a
reverse rotation engine with a chain drive, the cam bearing oil feed hole will require
repositioning to the opposite lower side. This is due to the fact that the camshaft is
turning in the opposite direction as noted above.
The AERA Technical Committee
Reference:
This information is provided from the best available sources. However, AERA does not assume
responsibility for data accuracy or consequences of its application. Members and others are not
authorized to reproduce or distribute this material in any form, or issue it to their branches,
divisions, or subsidiaries, etc. at a different location, without written permission.
© Copyright AERA 2006
TECHNICAL BULLETIN
July 2002
TB 1996
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grumpyvette
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17774
Age: 75
Loc: farmersville texas USA
Reg: 03-16-01
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02-16-11 01:51 PM - Post#2047530
In response to Kozmo
http://www.dura-bondbearing.com/Portals/3/pdf/Cam%...
heres that diagram
http://www.pbw-india.com/theory.htm
heres more info
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!! |
Edited by grumpyvette on 02-16-11 01:57 PM. Reason for edit: No reason given.
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motorman
Dedicated Enthusiast
Posts: 5189
Loc: south western pa.
Reg: 01-25-00
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02-16-11 04:33 PM - Post#2047603
In response to Kozmo
the highest load on a cam bearing is at the 6 o'clock position and the is why BBC have the oil feed at that position because the valve train is pushing downward on the cam all the time. the rod crank bearing load is the highest at the upper position because the piston is pushing downward on the crank journal. that is the difference between the cam and the crank bearings loads
| retired race engine builder,former NASCAR tech inspector. new corvettes owned 1959,1962,1963,1964,1965, 1966,1997,1999,2002,2005, 2008 plus 30+ other chevy cars and trucks along the way. 2008 corvette sold and waiting on a C-7. |
Edited by motorman on 02-16-11 04:36 PM. Reason for edit: No reason given.
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grumpyvette
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17774
Age: 75
Loc: farmersville texas USA
Reg: 03-16-01
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02-16-11 05:31 PM - Post#2047630
In response to motorman
think about what you just posted, and read it again ,
the highest loads on the cam are at 6 o'clock as stated, because the spring loads on the lifters on both sides push down equally and so are the crank main bearing loads, because the cylinders firing on opposite banks are roughly equal an the net effect is a downward load on the main caps
because the valve train is pushing downward on the cam all the time, at approximately the 10 o'clock and 2 o'clock positions, the rods exert force on the crank bearing loads in approximately the same way,oil feeds need to be in the 12 o'clock to 2 o'clock location for maximum oil wedge to form and support the spinning crank or cam bearings
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!! |
Edited by grumpyvette on 02-16-11 05:38 PM. Reason for edit: No reason given.
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motorman
Dedicated Enthusiast
Posts: 5189
Loc: south western pa.
Reg: 01-25-00
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02-16-11 09:03 PM - Post#2047731
In response to grumpyvette
think about what you just posted, and read it again ,
the highest loads on the cam are at 6 o'clock as stated, because the spring loads on the lifters on both sides push down equally and so are the crank main bearing loads, because the cylinders firing on opposite banks are roughly equal an the net effect is a downward load on the main caps
because the valve train is pushing downward on the cam all the time, at approximately the 10 o'clock and 2 o'clock positions, the rods exert force on the crank bearing loads in approximately the same way,oil feeds need to be in the 12 o'clock to 2 o'clock location for maximum oil wedge to form and support the spinning crank or cam bearings
that is what i posted the bearing load on the cam bearings are at the bottom but the loads on the rod bearings are at the top. the load on the main bearings is at the bottom
| retired race engine builder,former NASCAR tech inspector. new corvettes owned 1959,1962,1963,1964,1965, 1966,1997,1999,2002,2005, 2008 plus 30+ other chevy cars and trucks along the way. 2008 corvette sold and waiting on a C-7. |
Edited by motorman on 02-16-11 09:04 PM. Reason for edit: No reason given.
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85Camaro
Senior Member
Posts: 1161
Loc: East TN
Reg: 07-14-01
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02-20-11 09:30 AM - Post#2049294
In response to motorman
My rod bearings don't have any holes, what should I do?
In all honesty on a street SBC you can put the hole of the can bearing any way you want and as long as you put the right bearing in the right position and don't beat the cam in with a hammer you won't have any problems. I've seen them in every position possible with no problems.
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grumpyvette
Senior Chevytalk Moderator -- Performance Subject Matter Expert --
Posts: 17774
Age: 75
Loc: farmersville texas USA
Reg: 03-16-01
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02-20-11 10:06 AM - Post#2049319
In response to 85Camaro
My rod bearings don't have any holes, what should I do?
.
their not supposed to have holes oil feeds from the crank journal to the bearing surface not thru the bearing shell as on main bearings or cam bearings
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!! |
Edited by grumpyvette on 02-20-11 10:09 AM. Reason for edit: No reason given.
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boogie
Senior Member
Posts: 2233
Loc: Louisiana
Reg: 07-11-02
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02-20-11 03:40 PM - Post#2049487
In response to Kozmo
Here is how I install them and also the way I find them installed as the factory installed them:
With block upright and facing the front
#1 holes at 1 and 4 oclock
#2 hole at 4 oclock
#3 hole at 4 oclock
#4 hole at 4 oclock
#5 hole at 12 oclock
| '85 GMC C1500 SWB 355 sbc |
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