Any one interested in the oiling mods I did?

[gregcon]

The oil in the galley is not rushing past any leaks. It is flowing to each and every leak. The problem comes when the leaks at one area (like the cam bearings) cause a deficit at another (the rods). There are two basic ways to address that - cut back the amount of losses at the cam (or rockers, etc.), and/or increase the overall amount of oil.

We've all agreed the cam bearing / rocker oil should be restricted. As for the increase in oil, you can achieve that by pumping harder or by improving the supply path. All of us do that (usually) by smoothing the edges or ports, enlarging passages, etc. But where we disagree is in the idea that oil velocity creates oil supply issues. Oil velocity is a byproduct of flow - you can't have flow without some velocity - but I don't believe the velocity is anywhere 'critical mass'.

 

[Duane]

I don't think so.
@gregcon is only questioning the one claim that oil 'shoots past' #4 or #2 main - it does not and could not.
I don't think he disagrees that there are other issues or reasons that the pressure at a particular main bearing may drop and he obviously stated that there are shortcomings in the oiling system which could be attributed to uneven oil distribution.

One other question he asked, which I thought was pertinent, was why enlarging the feed to the main would do any good since there's only so much oil available at the primary galley and the primary is already undersized. That increasing the ability to outflow really isn't going to help much since the supply side is already restricted. I think he made a good point with that, and since enlarging the primary feed is tough, double-feeding the primary would be the next best thing. I don't think he's wrong based on all the info that's been discussed and shared. Would it be the best way? I dunno, I haven't done oil system development on small block chryslers. But it's definitely A way to do it.

I think the thing to remember with all these mods is that the recommendations coming from Chrysler or the Larry Atherton book are not to be looked at individually. They are recommended for extreme applications. They are not recommended as to say lets do just this one. They are recommended as an all or nothing because they are interrelated. I have had this oiling discussion many times in the past and there are always non believers of this part or that.
I fail to see why anyone would question Chrysler. They have cast the r3 block with no oiling to the lifters because it was designed as a race block. A race blocks needs it oil path restricted because of the intended usage.
The sbm is not a new engine design. Many racers before us have raced it and can tell you about its oiling issues and how they got it to work. Sanborn was a very successful sbm racer who shared in much detail how he got the engine to live. He too was an engineer.
I had Cometic gaskets design Mls head gaskets for the sbm with the water passages modified to Sanborns design. Anyone on this forum can now buy them. The main bearing problems with sbm are very well documented as are the fixes. But some guys want to do there own thing. To each his own. But my own personal experience with my own engines is that tubing the block and opening the passages works. Restricting the cam bearings works, Reading the article you referenced has confirmed what I thought. Rod bearings oil from centrifugal force, viewing the rod oiling from that perspective makes me realize that opening the main passages to 5/16 and slotting the bearing shells increases the dwell time to get oil into the crank passages.
The higher the rpm, the less time To get it in there. Those passages do not just feed the main bearings, and when the crank passage needs oil, you need to get it there quick.Opening any passage is the easiest way to improve flow and reduce pumping losses.

 

[Phreakish]

I think the thing to remember with all these mods is that the recommendations coming from Chrysler or the Larry Atherton book are not to be looked at individually. They are recommended for extreme applications. They are not recommended as to say lets do just this one. They are recommended as an all or nothing because they are interrelated. I have had this oiling discussion many times in the past and there are always non believers of this part or that.
I fail to see why anyone would question Chrysler. They have cast the r3 block with no oiling to the lifters because it was designed as a race block. A race blocks needs it oil path restricted because of the intended usage.
The sbm is not a new engine design. Many racers before us have raced it and can tell you about its oiling issues and how they got it to work. Sanborn was a very successful sbm racer who shared in much detail how he got the engine to live. He too was an engineer.
I had Cometic gaskets design Mls head gaskets for the sbm with the water passages modified to Sanborns design. Anyone on this forum can now buy them. The main bearing problems with sbm are very well documented as are the fixes. But some guys want to do there own thing. To each his own. But my own personal experience with my own engines is that tubing the block and opening the passages works. Restricting the cam bearings works, Reading the article you referenced has confirmed what I thought. Rod bearings oil from centrifugal force, viewing the rod oiling from that perspective makes me realize that opening the main passages to 5/16 and slotting the bearing shells increases the dwell time to get oil into the crank passages.
The higher the rpm, the less time To get it in there. Those passages do not just feed the main bearings, and when the crank passage needs oil, you need to get it there quick.Opening any passage is the easiest way to improve flow and reduce pumping losses.

Agreed - individual mods don't do squat. The mods are intended to reconfigure stock system to a racing system and are not intended to address specific shortcomings in any one area.

That's some of what's causing disagreement though, is that some steps are being discussed in isolation, and the reasoning invented to explain the steps just isn't accurate - even if it's a 'good' step to take toward reconfiguration, but no single step does much good (except for using a larger pickup and opening ALL the passages associated with the pump and filter - those should be made yuuuuuuge with respect to cross sectional area).

Just drilling the mains feeds larger is likely to cause more problems than gains. But do it AND block the cam feeds (restrict) and you've likely helped balance flow to some extent. Restricting feed at the #1 to the opposite lifter bank goes along with that.

But none of theses steps or reconfigurations is done to eliminate velocity. They're done to eliminate leaks PRIOR to feeding the mains. By doing so, the pressure available to the mains is retained and only drops after them, not before. That's basically what all the racing blocks did - they feed the mains first, the mains feed the cam, and the lifters are fed from the last cam feed. That last cam feed determines the flow potential to everything that's not a main bearing, and so chances for catastrophic oil pressure loss at the mains is reduced.

 

[Duane]

Agreed - individual mods don't do squat. The mods are intended to reconfigure stock system to a racing system and are not intended to address specific shortcomings in any one area.

That's some of what's causing disagreement though, is that some steps are being discussed in isolation, and the reasoning invented to explain the steps just isn't accurate - even if it's a 'good' step to take toward reconfiguration, but no single step does much good (except for using a larger pickup and opening ALL the passages associated with the pump and filter - those should be made yuuuuuuge with respect to cross sectional area).

Just drilling the mains feeds larger is likely to cause more problems than gains. But do it AND block the cam feeds (restrict) and you've likely helped balance flow to some extent. Restricting feed at the #1 to the opposite lifter bank goes along with that.

But none of theses steps or reconfigurations is done to eliminate velocity. They're done to eliminate leaks PRIOR to feeding the mains. By doing so, the pressure available to the mains is retained and only drops after them, not before. That's basically what all the racing blocks did - they feed the mains first, the mains feed the cam, and the lifters are fed from the last cam feed. That last cam feed determines the flow potential to everything that's not a main bearing, and so chances for catastrophic oil pressure loss at the mains is reduced.

Agreed with all but your last paragraph. If you can, try to get a copy of the Larry Atherton book. It explains both recommended modification and explains the velocity issue. The book goes into detail about the crossover tube and the"proper" way to install it. It is designed to slow the oil when using wet lifters only.
The designer of that crossover was Bob Mullen, a highly respected member of the society of automotive engineers, and the inventer of the W2 head. The crossover method was designed to slow velocity
While still have all the lifter oil leaks. Those leaks are what causes the issue. The Chrysler method is to cut the leaks with a system that resembles Gregcons sketch. Both methods are designed to fix the same problem. One with the leaks, one without.
It is Sanborns method of front oiling that is unique. Even his method uses wet lifters but highly restricted.
The book claims that the crossover method was tested reliable to 10,000 rpm and was used in Bob Gliddens pro stock car. The drawback to the crossover is it is difficult to implement correctly.

 

[Duane]

The oil in the galley is not rushing past any leaks. It is flowing to each and every leak. The problem comes when the leaks at one area (like the cam bearings) cause a deficit at another (the rods). There are two basic ways to address that - cut back the amount of losses at the cam (or rockers, etc.), and/or increase the overall amount of oil.

We've all agreed the cam bearing / rocker oil should be restricted. As for the increase in oil, you can achieve that by pumping harder or by improving the supply path. All of us do that (usually) by smoothing the edges or ports, enlarging passages, etc. But where we disagree is in the idea that oil velocity creates oil supply issues. Oil velocity is a byproduct of flow - you can't have flow without some velocity - but I don't believe the velocity is anywhere 'critical mass'.

I find it ironic that you accept all the oiling fixes that the pioneers figured out years ago, but you do not accept the explanation of what you are fixing coming from those same pioneers.
No one in this thread that i can recall has said that rod bearing oiling is a problem. It is main bearings and not all of them.
I agree that you will have some velocity with flow, but putting in that big pump in a "stock" system make it excessive. Even a stock engine restricts oil to the rockers with its timed system of pulse oiling. I have found out the hard way that the mains will not pressurize properly without that restriction.

 

[yellow rose]

Agreed with all but your last paragraph. If you can, try to get a copy of the Larry Atherton book. It explains both recommended modification and explains the velocity issue. The book goes into detail about the crossover tube and the"proper" way to install it. It is designed to slow the oil when using wet lifters only.
The designer of that crossover was Bob Mullen, a highly respected member of the society of automotive engineers, and the inventer of the W2 head. The crossover method was designed to slow velocity
While still have all the lifter oil leaks. Those leaks are what causes the issue. The Chrysler method is to cut the leaks with a system that resembles Gregcons sketch. Both methods are designed to fix the same problem. One with the leaks, one without.
It is Sanborns method of front oiling that is unique. Even his method uses wet lifters but highly restricted.
The book claims that the crossover method was tested reliable to 10,000 rpm and was used in Bob Gliddens pro stock car. The drawback to the crossover is it is difficult to implement correctly.

Can you define “wet” lifters for me? I’m not exactly sure what that means.

Also, I always open the main feeds to .287 because I’ve seen many of those feeds that have steps in them. And I don’t want a change in cross section there.

I think .312 may be on the big side, but the limit to any flow will always be the smallest restriction in the circuit. For main/rod oiling that’s going to be the holes in the crank and at the very end, bearing clearance.

One last point is I’m pretty sure I have the Atherton book and several others that cover the velocity issue. One thing they never answered is how they determined how they tested for velocity in the gallery.

I must be the only guy who has never hurt a main bearing. Now I’m going to have to pull some main caps and have a look at my mains.

 

[yellow rose]

I find it ironic that you accept all the oiling fixes that the pioneers figured out years ago, but you do not accept the explanation of what you are fixing coming from those same pioneers.
No one in this thread that i can recall has said that rod bearing oiling is a problem. It is main bearings and not all of them.
I agree that you will have some velocity with flow, but putting in that big pump in a "stock" system make it excessive. Even a stock engine restricts oil to the rockers with its timed system of pulse oiling. I have found out the hard way that the mains will not pressurize properly without that restriction.

LOL. Read post 406. Rod bearing failure is an oil timing issue. If you are killing the mains, I have no idea how it’s not getting the rods too.

 

[Phreakish]

Agreed with all but your last paragraph. If you can, try to get a copy of the Larry Atherton book. It explains both recommended modification and explains the velocity issue. The book goes into detail about the crossover tube and the"proper" way to install it. It is designed to slow the oil when using wet lifters only.
The designer of that crossover was Bob Mullen, a highly respected member of the society of automotive engineers, and the inventer of the W2 head. The crossover method was designed to slow velocity
While still have all the lifter oil leaks. Those leaks are what causes the issue. The Chrysler method is to cut the leaks with a system that resembles Gregcons sketch. Both methods are designed to fix the same problem. One with the leaks, one without.
It is Sanborns method of front oiling that is unique. Even his method uses wet lifters but highly restricted.
The book claims that the crossover method was tested reliable to 10,000 rpm and was used in Bob Gliddens pro stock car. The drawback to the crossover is it is difficult to implement correctly.

Im sure the crossover works, but I don't buy the velocity explanation. Nothing in my education which includes fluid dynamics and plenty of experience with flow even suggests that velocity can play a part with a liquid.
Air? Sure. Oil? Does not compute.

Thing is, I can fully explain and comprehend why the crossover, restrictions, and drill all work without having to ever bring velocity into the equation.

 

[Duane]

Im sure the crossover works, but I don't buy the velocity explanation. Nothing in my education which includes fluid dynamics and plenty of experience with flow even suggests that velocity can play a part with a liquid.
Air? Sure. Oil? Does not compute.

Thing is, I can fully explain and comprehend why the crossover, restrictions, and drill all work without having to ever bring velocity into the equation.

Ok so explain why you agree that the crossover works. Perhaps we can look at it in a different perspective.

 

[yellow rose]

Im sure the crossover works, but I don't buy the velocity explanation. Nothing in my education which includes fluid dynamics and plenty of experience with flow even suggests that velocity can play a part with a liquid.
Air? Sure. Oil? Does not compute.

Thing is, I can fully explain and comprehend why the crossover, restrictions, and drill all work without having to ever bring velocity into the equation.

I’d love to hear how the crossover works, related to an engine with solid lifters, because anyone using hydraulic lifters can’t have an RPM oiling problem.

Ive never understood the crossover. As far as I can tell it does nothing.

 

[yellow rose]

Ok so explain why you agree that the crossover works. Perhaps we can look at it in a different perspective.

Damn got TREE’D.

 

[Duane]

LOL. Read post 406. Rod bearing failure is an oil timing issue. If you are killing the mains, I have no idea how it’s not getting the rods too.

After reading that rod bearings are pressurized by centrifugal force I am beginning to rethink the timing issue. I'm not so sure now.

 

[Phreakish]

The crossover is only there to get oil to the opposite bank without having rob the #1 main, and it works for that.

Getting oil there is necessary for oil thru lifters, hydraulic or not. Look at the size of the tubes used on those vintage builds - it didn't rob much oil from the primary lifter galley that's for sure.

 

[Phreakish]

After reading that rod bearings are pressurized by centrifugal force I am beginning to rethink the timing issue. I'm not so sure now.

There's two things to think about. Centrifugal force pressurizes the oil, but the passage to the rod only holds so much... That passage gets filled quickly each time it aligns with the mains feed, but doesn't fill very fast when main bearing clearance is minimal - hence grooved bearings. But at very high revs, even grooves likely can't keep up.

 

[Duane]

Can you define “wet” lifters for me? I’m not exactly sure what that means.

Also, I always open the main feeds to .287 because I’ve seen many of those feeds that have steps in them. And I don’t want a change in cross section there.

I think .312 may be on the big side, but the limit to any flow will always be the smallest restriction in the circuit. For main/rod oiling that’s going to be the holes in the crank and at the very end, bearing clearance.

One last point is I’m pretty sure I have the Atherton book and several others that cover the velocity issue. One thing they never answered is how they determined how they tested for velocity in the gallery.

I must be the only guy who has never hurt a main bearing. Now I’m going to have to pull some main caps and have a look at my mains.

Some amount of oil flow to the lifters, maybe highly restricted, but some. I agree on the step drilled holes.
If my memory serves, there was a guy named Rapid Robert on the forum who has another book by Atherton showing that he pressurized an unassembled block with a garden hose flowing water through the galley to see how the distribution of each main was flowing. Apparently number 4 had very little water come out with the majority coming out the front.
When you kicked the rods out, was the journal blued or blackish in colour?

 

[Phreakish]

Some amount of oil flow to the lifters, maybe highly restricted, but some. I agree on the step drilled holes.
If my memory serves, there was a guy named Rapid Robert on the forum who has another book by Atherton showing that he pressurized an unassembled block with a garden hose flowing water through the galley to see how the distribution of each main was flowing. Apparently number 4 had very little water come out with the majority coming out the front.
When you kicked the rods out, was the journal blued or blackish in colour?

A garden hose through a stripped block is not analogous to an assembled engine.

It is possible that there's some unique situation at #4 caused by machining methods or the way the oil passages are routed that results in a greater reduction of flow at #4 when outflows elsewhere exceed supply. But it's not due to velocity.. It would be due to an imbalance of flows caused by inconsistent flow demand at various passages.

 

[Duane]

There's two things to think about. Centrifugal force pressurizes the oil, but the passage to the rod only holds so much... That passage gets filled quickly each time it aligns with the mains feed, but doesn't fill very fast when main bearing clearance is minimal - hence grooved bearings. But at very high revs, even grooves likely can't keep up.

Agreed but I know that it was Sanborns theory also that the idea is to give the crank passage more time to fill. He addressed this by slotting the oil feed passage in the bearing and the block to 1/4 inch by 1/2 length to increase the dwell time, or the amount of time that the fill passage sees full flow. This does jive with Yellow roses theory of oil timing but differs on how the bearing is pressurized.

 

[Duane]

A garden hose through a stripped block is not analogous to an assembled engine.

It is possible that there's some unique situation at #4 caused by machining methods or the way the oil passages are routed that results in a greater reduction of flow at #4 when outflows elsewhere exceed supply. But it's not due to velocity.. It would be due to an imbalance of flows caused by inconsistent flow demand at various passages.

If you sealed the unnessesary passages I do not see how the test could not be valid. A hose say right at the rear galley port would simulate the location of the large volume of oil from the pump.
I don't know the details of the test, just the basis of how Atherton
Determine the unequal flow. To me it jives with my dash example.
A long galley opened at the far end, and the large volume of air or oil at the other tends to run right by the nearest passage to the pump until restricted down stream.

 

[Phreakish]

Yes, slotting the bearing or opening allows more time to fill.

But, higher centrifugal pressure at higher revs means the same oil supply doesn't last as long. If the rod passage is critically low on oil (or out) as the critical period approaches (nearing TDC or after it when major loads are applied) then it's a bigger problem than running out when there's no or light loads (passing bdc and coming back up). If high pressure oil is fed into the crank passage right around TDC, then there's always oil there at the right time, even if it runs out later.

 

[Duane]

The crossover is only there to get oil to the opposite bank without having rob the #1 main, and it works for that.

Getting oil there is necessary for oil thru lifters, hydraulic or not. Look at the size of the tubes used on those vintage builds - it didn't rob much oil from the primary lifter galley that's for sure.

That is not even close to the explanation of what a properly implemented Atherton/ Bob Mullen crossover is claimed to do.
I have seen all kinds of crossovers, anything from braid line with 90 degree aero quip fittings. That's why I said properly implemented.
The Atherton crossover requires precise exit and entrance angles.
It is claimed that these angles precisely channel a certain amount of oil to the drivers side to slow the oil speed on the passenger side to better allow the oil to make it to number four main. Not just any old crossover will work.

 

[Phreakish]

If you sealed the unnessesary passages I do not see how the test could not be valid. A hose say right at the rear galley port would simulate the location of the large volume of oil from the pump.
I don't know the details of the test, just the basis of how Atherton
Determine the unequal flow. To me it jives with my dash example.
A long galley opened at the far end, and the large volume of air or oil at the other tends to run right by the nearest passage to the pump until restricted down stream.

I don't know how the "test" was done, so I can only speculate, and if flown was simply being observed then I don't see how the proper passages could be plugged, since a crank has to be in a block for the passages to operate properly.

Your dash example is with air, air is compressible and the relative flow rate to cross section is entirely different.

An open passage would basically have the oil feed pressure dropping to zero, just like when cam bearings are toast. In that case velocity WILL dominate and momentum comes into play. However, working clearances in an oil system should never let pressure drop to zero. That's the big difference. If pressure is actually present in the primary galley, then velocity will not rob a passage of flow. It is possible to lose pressure in that galley though for a variety of reasons, but that does not mean the fix is to reduce velocity, it's to plug the hemmorage wherever it's happening! LOL

 

[Phreakish]

That is not even close to the explanation of what a properly implemented Atherton/ Bob Mullen crossover is claimed to do.
I have seen all kinds of crossovers, anything from braid line with 90 degree aero quip fittings. That's why I said properly implemented.
The Atherton crossover requires precise exit and entrance angles.
It is claimed that these angles precisely channel a certain amount of oil to the drivers side to slow the oil speed on the passenger side to better allow the oil to make it to number four main. Not just any old crossover will work.

I can't disagree more.

That sounds like a Wizarding explanation someone gives in order to confuse their competitors. Been there...

 

[Duane]

Yes, slotting the bearing or opening allows more time to fill.

But, higher centrifugal pressure at higher revs means the same oil supply doesn't last as long. If the rod passage is critically low on oil (or out) as the critical period approaches (nearing TDC or after it when major loads are applied) then it's a bigger problem than running out when there's no or light loads (passing bdc and coming back up). If high pressure oil is fed into the crank passage right around TDC, then there's always oil there at the right time, even if it runs out later.

Agreed that's where the timing comes in, but not necessarily for pressure as that's supplied the centrifugal force.

 

[Phreakish]

Agreed that's where the timing comes in, but not necessarily for pressure as that's supplied the centrifugal force.

Correct. Not for pressure, for supply. At least that's what I'm seeing. I don't have a motor apart right now to see how things actually line up during operation, LOL.

 

[Duane]

I don't know how the "test" was done, so I can only speculate, and if flown was simply being observed then I don't see how the proper passages could be plugged, since a crank has to be in a block for the passages to operate properly.

Your dash example is with air, air is compressible and the relative flow rate to cross section is entirely different.

An open passage would basically have the oil feed pressure dropping to zero, just like when cam bearings are toast. In that case velocity WILL dominate and momentum comes into play. However, working clearances in an oil system should never let pressure drop to zero. That's the big difference. If pressure is actually present in the primary galley, then velocity will not rob a passage of flow. It is possible to lose pressure in that galley though for a variety of reasons, but that does not mean the fix is to reduce velocity, it's to plug the hemmorage wherever it's happening! LOL

I would say that the ultimate test would be an engine that lives to 10,000 rpm and won the 1979 pro stock championship driven by Bob Glidden is enough ample proof for me.