milnersXcoupe
01-14-2007, 11:17 AM
Anyone familiar with this correction to the AMC oiling system - ?
- comments welcome before I break out the Black & Decker -
:razz:
:idea:
Found this on the .Net @ :
http://tinyurl.com/yz7j9u
Fixing AMC V8 Oiling (09/10/2006)
There are many sites that have information on resolving AMC V8 internal lubrication issues... none have truly addressed what completely resolves internal lubrication. Though they do resolve the issue at hand, only to bypass the so-called problem.
To fully understand what keeps the rear mains from getting full lubrication, one must look at two important issues with the oil passages and where they go.
Most AMC blocks are fairly old and may have been raced a time or two down the line. To keep things in order, lifter bore wear can be a big problem later down the road.
A good method to correct over lubrication at the lifter bores was taken from a Mopar thread.
The discussion was based on a factory fix for the 340 racing block.
The factory recommendation is to over-bore the two main oil galleries to 1/2", drilling just past the first four lifter bores on both galleries.
Once that has been done, go through the backside of the gallery and perform the same thing on both galleries (This is a over 10" length).
Drive in an appropriate length 1/2" OD x 3/8" ID pipe and thread both ends for the 3/8" NPT gallery plugs.
This is to be done on both galleries.
Re-drill through the mains oil passages to create openings in the new pipe.
To drill lifter bore holes; Place a lifter with a machined bottom that has been rounded off into the bore and drive it through.
This will push against the pipe and dent it for clearance. Drill a new 1/4" lifter bore oiling hole for each lifter through the pipe.
To simplify the details of AMC V8 oiling, the lifter bores and the cam bearing bores all share one thing in common.
The bores intersect the oil passageway in such a manor that the lubrication hole is 3 to 4 times longer than it is taller.
Only if the mains had this type of oiling!
I call it Suicide oiling... and there are 16 of those buggers just waiting to spew.
Above is a representation of the oil passage (shown in red) intersecting the cam bore (shown in black). Note that the cam bearing (shown in yellow) also intersects the oil passage, thus restricting the oil passage.
The cam is immune to this since bearings are already used and limit the amount of lubrication. But the cam bearing outer surface area becomes part of the oil passageway wall, since the intersection between them overlaps.
So when you check the lubrication hole in the main bore, the passageway at the cam bore is restricted enough to be a drill size (or more) smaller. Many overlook this!
It would not hurt to re-drill the mains lubrication hole oversize.
This must be done if using roller cam bearings anyway.
Another option is to drill another set of lubrication passages from the same mains hole to the opposite gallery.
**{can this be done on a 360 ? thought only on a 401}**
A skilled hand drill user with the proper bit can do the over-sizing of the mains lubrication passageway just past the cam bore.
Now that I have explained this... I see that they were right about the mains being last... since the lifters have over kill lubrication, which makes them top dog, and the restriction from the cam bearing overlap with passageway wall keeps the mains in the dog house.
This truly fixes the issue and eliminates 3 options:
1) Oil passage bypass (which cannot be monitored without pulling the intake) - Doubles the flow on the passenger side oil gallery. It is equal to restricting the oil gallery on the opposite side.
2) Drilling more passages for the mains - Adds more flow to the mains from the driver side oil gallery. Cheaper to add an equalizing line on the two galleries bore holes at the end of the block.
3) Using modified oil pump gear set - adds more volume and maintains better pressure at high RPM.
* Interesting plan - is the material around the galleries the same for the 360 as is a 401 ? #-o
- comments welcome before I break out the Black & Decker -
:razz:
:idea:
Found this on the .Net @ :
http://tinyurl.com/yz7j9u
Fixing AMC V8 Oiling (09/10/2006)
There are many sites that have information on resolving AMC V8 internal lubrication issues... none have truly addressed what completely resolves internal lubrication. Though they do resolve the issue at hand, only to bypass the so-called problem.
To fully understand what keeps the rear mains from getting full lubrication, one must look at two important issues with the oil passages and where they go.
Most AMC blocks are fairly old and may have been raced a time or two down the line. To keep things in order, lifter bore wear can be a big problem later down the road.
A good method to correct over lubrication at the lifter bores was taken from a Mopar thread.
The discussion was based on a factory fix for the 340 racing block.
The factory recommendation is to over-bore the two main oil galleries to 1/2", drilling just past the first four lifter bores on both galleries.
Once that has been done, go through the backside of the gallery and perform the same thing on both galleries (This is a over 10" length).
Drive in an appropriate length 1/2" OD x 3/8" ID pipe and thread both ends for the 3/8" NPT gallery plugs.
This is to be done on both galleries.
Re-drill through the mains oil passages to create openings in the new pipe.
To drill lifter bore holes; Place a lifter with a machined bottom that has been rounded off into the bore and drive it through.
This will push against the pipe and dent it for clearance. Drill a new 1/4" lifter bore oiling hole for each lifter through the pipe.
To simplify the details of AMC V8 oiling, the lifter bores and the cam bearing bores all share one thing in common.
The bores intersect the oil passageway in such a manor that the lubrication hole is 3 to 4 times longer than it is taller.
Only if the mains had this type of oiling!
I call it Suicide oiling... and there are 16 of those buggers just waiting to spew.
Above is a representation of the oil passage (shown in red) intersecting the cam bore (shown in black). Note that the cam bearing (shown in yellow) also intersects the oil passage, thus restricting the oil passage.
The cam is immune to this since bearings are already used and limit the amount of lubrication. But the cam bearing outer surface area becomes part of the oil passageway wall, since the intersection between them overlaps.
So when you check the lubrication hole in the main bore, the passageway at the cam bore is restricted enough to be a drill size (or more) smaller. Many overlook this!
It would not hurt to re-drill the mains lubrication hole oversize.
This must be done if using roller cam bearings anyway.
Another option is to drill another set of lubrication passages from the same mains hole to the opposite gallery.
**{can this be done on a 360 ? thought only on a 401}**
A skilled hand drill user with the proper bit can do the over-sizing of the mains lubrication passageway just past the cam bore.
Now that I have explained this... I see that they were right about the mains being last... since the lifters have over kill lubrication, which makes them top dog, and the restriction from the cam bearing overlap with passageway wall keeps the mains in the dog house.
This truly fixes the issue and eliminates 3 options:
1) Oil passage bypass (which cannot be monitored without pulling the intake) - Doubles the flow on the passenger side oil gallery. It is equal to restricting the oil gallery on the opposite side.
2) Drilling more passages for the mains - Adds more flow to the mains from the driver side oil gallery. Cheaper to add an equalizing line on the two galleries bore holes at the end of the block.
3) Using modified oil pump gear set - adds more volume and maintains better pressure at high RPM.
* Interesting plan - is the material around the galleries the same for the 360 as is a 401 ? #-o
