when are 3/4 grooved main bearings needed for bbc ?

[Kevin Johnson]

Here’s a question. Does the oil in the main bearing groove need to accelerate to the crank main journal surface speed before it can be pushed into the oil feel passage? I think it needs to.

Meernik. One of those damn SAE papers you complained that I recommended reading.

https://www.sae.org/publications/techni ... nt/860229/

[ClassAct]

No confusion on my part concerning priority main oiling and oil timing. I was just wanting to get warpspeeds thoughts concerning Darts Iron Eagle engine block compared to the R0-7 as far as the way in which the oil is routed through the block. As far as oil timing goes, i have left that up to Winberg Crankshaft manufacturing to get it correct. You stated an engine (block) with incorrect oil timing, would you mind explaining what that means please ? Mark H

The oil feed hole in the block has to line up with the oil hole in the crank at the correct time. All the engines I've listed above have very advanced oil timing, meaning the oil hole in the block is way ahead of where it should be. And unless something has changed, you can't move the hole in the crank far enough to fix it.

Fought this deal for years. Guys that don't understand oil timing always say "dry sump it". I would, except it won't fix the oil timing issue. And many say "I've turned my stuff XXXX RPM and it lived". I can say where I live and hang out, I've never seen anyone do it. Ever. Fords, Pontiac, Chrysler whatever.

I remember I ordered a set of lifters from a well known company. They showed up and they were garbage. So I called them and I said "I'm shifting at 8500...is this the lifter you want me to use?" The answer was HELL NO. It won't live. And then the guy asks me who told me to order that lifter. I had copious notes. Same dude I had on the phone.

Then he admitted that many guys call up and claim they turn 8000,8500 what ever and he knows they are bullshitting. I wasn't.

Again, please clarify the "block timing" you are referring to!?!
All engines you speak of have an oil passage that feed a groove in the upper bearing. The only way to effectively change the "timing", is to move the groove to a different part of the bearing, or move the feed hole in the crank.
Please explain, as I (and a few others) have no idea what your talking about.

Warp, there has to be a feed hole in the block that lines up with the oil feed hole in the main journal. That needs to happen at about 70 degrees ATDC. You can't move the oil hole in the crank very much. So the feed hole in the block needs to be in a location so that the feed hole in the block lines up with the oil hole in the crank at the 70 degree timing.

If you look at a Chrysler block (even the much vaunted R series of blocks), small or big block and you'll see that oil feed hole that comes down from the oil gallery will be putting the oil out to the rods about 15-20 degrees too soon. I apologize for not remembering the exact number because it's been years since I actually measured it out, but it's that early.

As RPM and/or load or both go up, that advanced oil timing will absolutely not feed oil to the rods at the correct time and we both know what happens when that rule of oil timing is off!!! You can up the pressure, use full groove mains, you can slot the feed hole in the block over towards the feed hole that goes up to the cam bearing, you can change the hole in the bearing to a slot, you can use a crossover tube (which does NOTHING)...I can name some other stuff but none of that can fix that oil timing issue.

And it's not just the Chrysler stuff that has the feed hole in the block in an advanced position. Ford, Buick, Pontiac and IIRC Olds all have the oil timing advanced to some degree.

At lower RPM/loads it really doesn't matter. But when you start running up the power and the RPM's it will start to show up...bearings getting hot...whatever. So you end up with full groove mains so there is some oil there all the time. Up the RPM/load again and it will start again. So you start doing all the crap that the "tech" books tell you to do, and if you are lucky, it will help. A bit. At some point though, you have to correct the timing issue or slow the engine speed down.

That's what I talking about when I say the oil timing is advanced in any of these blocks, even some of the aftermarket blocks.

It's two things. The oil feed hole in the block and the oil feed hole to the rods in the main bearing journal. Together, those two better line up about 70 degrees ATDC or you end up in a world of crap.

I hope I have made this understandable.

Can you address this Warp and give your thoughts? I'm sure many (myself included) would love to hear what you think. And Hoffman and Jon Schmidt if he's watching this. And Kevin Johnson too.

I know all of you (and many others on here) are involved in developing new stuff all the time and what you think may clear up some misconceptions and actually teach people that oil timing is a thing and it matters.

Thanks

[Kevin Johnson]

One of the problems with aerated oil is hysteresis or a delay from the typically assumed simultaneity in an ideal hydraulic circuit. When engine oil became commonly used as an actuating fluid a great deal more attention was paid to air release values and deaeration schema.

[ClassAct]

One of the problems with aerated oil is hysteresis or a delay from the typically assumed simultaneity in an ideal hydraulic circuit. When engine oil became commonly used as an actuating fluid a great deal more attention was paid to air release values and deaeration schema.

Thank you Kevin!

Which is one reason why the latest stuff can run so little total oil volume and still feed everything and not go off like a grenade.

You can reduce the volume of oil used when things like the above are considered. And that gets back to one of Warps issues with full groove mains and the excessive oil volume they add to the system...which increases windage loss...which entrails more air...etc and if have this incorrect please correct it for me Kevin.

Thank you

[Kevin Johnson]

I think an ounce of prevention is worth a pound of cure. Design the system to avoid known problems and you have more freedom to optimize other elements.

[Warp Speed]

The oil feed hole in the block has to line up with the oil hole in the crank at the correct time. All the engines I've listed above have very advanced oil timing, meaning the oil hole in the block is way ahead of where it should be. And unless something has changed, you can't move the hole in the crank far enough to fix it.

Fought this deal for years. Guys that don't understand oil timing always say "dry sump it". I would, except it won't fix the oil timing issue. And many say "I've turned my stuff XXXX RPM and it lived". I can say where I live and hang out, I've never seen anyone do it. Ever. Fords, Pontiac, Chrysler whatever.

I remember I ordered a set of lifters from a well known company. They showed up and they were garbage. So I called them and I said "I'm shifting at 8500...is this the lifter you want me to use?" The answer was HELL NO. It won't live. And then the guy asks me who told me to order that lifter. I had copious notes. Same dude I had on the phone.

Then he admitted that many guys call up and claim they turn 8000,8500 what ever and he knows they are bullshitting. I wasn't.

Again, please clarify the "block timing" you are referring to!?!
All engines you speak of have an oil passage that feed a groove in the upper bearing. The only way to effectively change the "timing", is to move the groove to a different part of the bearing, or move the feed hole in the crank.
Please explain, as I (and a few others) have no idea what your talking about.

Warp, there has to be a feed hole in the block that lines up with the oil feed hole in the main journal. That needs to happen at about 70 degrees ATDC. You can't move the oil hole in the crank very much. So the feed hole in the block needs to be in a location so that the feed hole in the block lines up with the oil hole in the crank at the 70 degree timing.

If you look at a Chrysler block (even the much vaunted R series of blocks), small or big block and you'll see that oil feed hole that comes down from the oil gallery will be putting the oil out to the rods about 15-20 degrees too soon. I apologize for not remembering the exact number because it's been years since I actually measured it out, but it's that early.

As RPM and/or load or both go up, that advanced oil timing will absolutely not feed oil to the rods at the correct time and we both know what happens when that rule of oil timing is off!!! You can up the pressure, use full groove mains, you can slot the feed hole in the block over towards the feed hole that goes up to the cam bearing, you can change the hole in the bearing to a slot, you can use a crossover tube (which does NOTHING)...I can name some other stuff but none of that can fix that oil timing issue.

And it's not just the Chrysler stuff that has the feed hole in the block in an advanced position. Ford, Buick, Pontiac and IIRC Olds all have the oil timing advanced to some degree.

At lower RPM/loads it really doesn't matter. But when you start running up the power and the RPM's it will start to show up...bearings getting hot...whatever. So you end up with full groove mains so there is some oil there all the time. Up the RPM/load again and it will start again. So you start doing all the crap that the "tech" books tell you to do, and if you are lucky, it will help. A bit. At some point though, you have to correct the timing issue or slow the engine speed down.

That's what I talking about when I say the oil timing is advanced in any of these blocks, even some of the aftermarket blocks.

It's two things. The oil feed hole in the block and the oil feed hole to the rods in the main bearing journal. Together, those two better line up about 70 degrees ATDC or you end up in a world of crap.

I hope I have made this understandable.

Can you address this Warp and give your thoughts? I'm sure many (myself included) would love to hear what you think. And Hoffman and Jon Schmidt if he's watching this. And Kevin Johnson too.

I know all of you (and many others on here) are involved in developing new stuff all the time and what you think may clear up some misconceptions and actually teach people that oil timing is a thing and it matters.

Thanks

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

[ClassAct]

Again, please clarify the "block timing" you are referring to!?!
All engines you speak of have an oil passage that feed a groove in the upper bearing. The only way to effectively change the "timing", is to move the groove to a different part of the bearing, or move the feed hole in the crank.
Please explain, as I (and a few others) have no idea what your talking about.

Warp, there has to be a feed hole in the block that lines up with the oil feed hole in the main journal. That needs to happen at about 70 degrees ATDC. You can't move the oil hole in the crank very much. So the feed hole in the block needs to be in a location so that the feed hole in the block lines up with the oil hole in the crank at the 70 degree timing.

If you look at a Chrysler block (even the much vaunted R series of blocks), small or big block and you'll see that oil feed hole that comes down from the oil gallery will be putting the oil out to the rods about 15-20 degrees too soon. I apologize for not remembering the exact number because it's been years since I actually measured it out, but it's that early.

As RPM and/or load or both go up, that advanced oil timing will absolutely not feed oil to the rods at the correct time and we both know what happens when that rule of oil timing is off!!! You can up the pressure, use full groove mains, you can slot the feed hole in the block over towards the feed hole that goes up to the cam bearing, you can change the hole in the bearing to a slot, you can use a crossover tube (which does NOTHING)...I can name some other stuff but none of that can fix that oil timing issue.

And it's not just the Chrysler stuff that has the feed hole in the block in an advanced position. Ford, Buick, Pontiac and IIRC Olds all have the oil timing advanced to some degree.

At lower RPM/loads it really doesn't matter. But when you start running up the power and the RPM's it will start to show up...bearings getting hot...whatever. So you end up with full groove mains so there is some oil there all the time. Up the RPM/load again and it will start again. So you start doing all the crap that the "tech" books tell you to do, and if you are lucky, it will help. A bit. At some point though, you have to correct the timing issue or slow the engine speed down.

That's what I talking about when I say the oil timing is advanced in any of these blocks, even some of the aftermarket blocks.

It's two things. The oil feed hole in the block and the oil feed hole to the rods in the main bearing journal. Together, those two better line up about 70 degrees ATDC or you end up in a world of crap.

I hope I have made this understandable.

Can you address this Warp and give your thoughts? I'm sure many (myself included) would love to hear what you think. And Hoffman and Jon Schmidt if he's watching this. And Kevin Johnson too.

I know all of you (and many others on here) are involved in developing new stuff all the time and what you think may clear up some misconceptions and actually teach people that oil timing is a thing and it matters.

Thanks

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

[Warp Speed]

Warp, there has to be a feed hole in the block that lines up with the oil feed hole in the main journal. That needs to happen at about 70 degrees ATDC. You can't move the oil hole in the crank very much. So the feed hole in the block needs to be in a location so that the feed hole in the block lines up with the oil hole in the crank at the 70 degree timing.

If you look at a Chrysler block (even the much vaunted R series of blocks), small or big block and you'll see that oil feed hole that comes down from the oil gallery will be putting the oil out to the rods about 15-20 degrees too soon. I apologize for not remembering the exact number because it's been years since I actually measured it out, but it's that early.

As RPM and/or load or both go up, that advanced oil timing will absolutely not feed oil to the rods at the correct time and we both know what happens when that rule of oil timing is off!!! You can up the pressure, use full groove mains, you can slot the feed hole in the block over towards the feed hole that goes up to the cam bearing, you can change the hole in the bearing to a slot, you can use a crossover tube (which does NOTHING)...I can name some other stuff but none of that can fix that oil timing issue.

And it's not just the Chrysler stuff that has the feed hole in the block in an advanced position. Ford, Buick, Pontiac and IIRC Olds all have the oil timing advanced to some degree.

At lower RPM/loads it really doesn't matter. But when you start running up the power and the RPM's it will start to show up...bearings getting hot...whatever. So you end up with full groove mains so there is some oil there all the time. Up the RPM/load again and it will start again. So you start doing all the crap that the "tech" books tell you to do, and if you are lucky, it will help. A bit. At some point though, you have to correct the timing issue or slow the engine speed down.

That's what I talking about when I say the oil timing is advanced in any of these blocks, even some of the aftermarket blocks.

It's two things. The oil feed hole in the block and the oil feed hole to the rods in the main bearing journal. Together, those two better line up about 70 degrees ATDC or you end up in a world of crap.

I hope I have made this understandable.

Can you address this Warp and give your thoughts? I'm sure many (myself included) would love to hear what you think. And Hoffman and Jon Schmidt if he's watching this. And Kevin Johnson too.

I know all of you (and many others on here) are involved in developing new stuff all the time and what you think may clear up some misconceptions and actually teach people that oil timing is a thing and it matters.

Thanks

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

And your theory is based on?

[ptuomov]

The reason why I'm asking about whether people think the oil in the groove needs to first accelerate to the surface speed of the journal before it can go into the groove is that that seems to be first-order relevant to the length of the groove and the direction in which the oil should flow into the groove.

[ptuomov]

The reason why I'm asking about whether people think the oil in the groove needs to first accelerate to the surface speed of the journal before it can go into the inlet hole in the main journal is that that seems to be first-order relevant to the length of the groove and flow direction inside the groove.

Mistakes fixed there.

[MELWAY]

Warp, there has to be a feed hole in the block that lines up with the oil feed hole in the main journal. That needs to happen at about 70 degrees ATDC. You can't move the oil hole in the crank very much. So the feed hole in the block needs to be in a location so that the feed hole in the block lines up with the oil hole in the crank at the 70 degree timing.

If you look at a Chrysler block (even the much vaunted R series of blocks), small or big block and you'll see that oil feed hole that comes down from the oil gallery will be putting the oil out to the rods about 15-20 degrees too soon. I apologize for not remembering the exact number because it's been years since I actually measured it out, but it's that early.

As RPM and/or load or both go up, that advanced oil timing will absolutely not feed oil to the rods at the correct time and we both know what happens when that rule of oil timing is off!!! You can up the pressure, use full groove mains, you can slot the feed hole in the block over towards the feed hole that goes up to the cam bearing, you can change the hole in the bearing to a slot, you can use a crossover tube (which does NOTHING)...I can name some other stuff but none of that can fix that oil timing issue.

And it's not just the Chrysler stuff that has the feed hole in the block in an advanced position. Ford, Buick, Pontiac and IIRC Olds all have the oil timing advanced to some degree.

At lower RPM/loads it really doesn't matter. But when you start running up the power and the RPM's it will start to show up...bearings getting hot...whatever. So you end up with full groove mains so there is some oil there all the time. Up the RPM/load again and it will start again. So you start doing all the crap that the "tech" books tell you to do, and if you are lucky, it will help. A bit. At some point though, you have to correct the timing issue or slow the engine speed down.

That's what I talking about when I say the oil timing is advanced in any of these blocks, even some of the aftermarket blocks.

It's two things. The oil feed hole in the block and the oil feed hole to the rods in the main bearing journal. Together, those two better line up about 70 degrees ATDC or you end up in a world of crap.

I hope I have made this understandable.

Can you address this Warp and give your thoughts? I'm sure many (myself included) would love to hear what you think. And Hoffman and Jon Schmidt if he's watching this. And Kevin Johnson too.

I know all of you (and many others on here) are involved in developing new stuff all the time and what you think may clear up some misconceptions and actually teach people that oil timing is a thing and it matters.

Thanks

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

If this is really the case. Then how much exposure time would the 2 holes have being in alignment at 9000+ rpm.
I think if the upper groove is at stable pressure. That would be more important to constant oil flow through the crank oil drilling’s

[ClassAct]

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

And your theory is based on?

Based on experience and facts. If you think you can put the holes anywhere you want, you be mistaken. Maybe on the new stuff you use, but not on anything else.

If you want to see how correct I am, pick any engine with the oil hole in the block not lining up with the oil hole in the crank at ~70 degrees ATDC and put it on the pump and turn it 8500. You'll count on one hand how many times you can make a pull before a Rod comes out. My bet is 3 max.

What's sad is who knows this, and who doesn't. Those who do started in classes like Modified Eliminator and we're stuck using stock blocks because that's all they had.

You can put the oil feed hole anywhere in the main bore, as long as the hole in the main journal lines up with that feed hole in the block at about 70 degrees ATDC.

When all the cranks are drilled the same, and the feed holes in the block are not, that's the wrong oil timing. And a full groove main won't fix it. Neither will all the other crap that is palmed off as a fix. You have to reclock the oil feed hole in the block.

And it begs the question...why will a run of the mill SBC RPM to as high as you want, and a small block Chrysler, BB Chrylser, Pontiac, Ford etc not? It should be easy to figure out.

[ClassAct]

So what you are implying, is that when the hole in the bearing/main web line up to the rod feed hole in the crank, is of the utmost importance?!?
What is the groove for?!?
The positioning of the pasage in the block, and even the angle it approaches can have a slight effect, but as long as supply to the passage in the bulkhead is good, its a non factor. That is why the bearing groove is there, to feed the rod for longer than when the two holes line up?!?
If your saying this is the root cause, I definitely do not agree.

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

If this is really the case. Then how much exposure time would the 2 holes have being in alignment at 9000+ rpm.
I think if the upper groove is at stable pressure. That would be more important to constant oil flow through the crank oil drilling’s

The time the holes line up will always be the same. So you're missing the point. If the hole in the block and the hol in the crank DO NOT LINE UP AT THE CORRECT TIME you have an issue.

That's why there is a groove in the upper shell. You've got to get the oil moving, so the groove does that. But those two holes better line up, or you will run over stuff.

Basic hydraulics really.

[Warp Speed]

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

And your theory is based on?

Based on experience and facts. If you think you can put the holes anywhere you want, you be mistaken. Maybe on the new stuff you use, but not on anything else.

If you want to see how correct I am, pick any engine with the oil hole in the block not lining up with the oil hole in the crank at ~70 degrees ATDC and put it on the pump and turn it 8500. You'll count on one hand how many times you can make a pull before a Rod comes out. My bet is 3 max.

What's sad is who knows this, and who doesn't. Those who do started in classes like Modified Eliminator and we're stuck using stock blocks because that's all they had.

You can put the oil feed hole anywhere in the main bore, as long as the hole in the main journal lines up with that feed hole in the block at about 70 degrees ATDC.

When all the cranks are drilled the same, and the feed holes in the block are not, that's the wrong oil timing. And a full groove main won't fix it. Neither will all the other crap that is palmed off as a fix. You have to reclock the oil feed hole in the block.

And it begs the question...why will a run of the mill SBC RPM to as high as you want, and a small block Chrysler, BB Chrylser, Pontiac, Ford etc not? It should be easy to figure out.

So you are saying +/- 5* (maybe 10*) of hole placement in the block, as typical of your examples, spells doom?!?

[Warp Speed]

I does make a difference and it's a big difference. As I said earlier you can slot, slit, notch and anything and everything else but it won't fix it.

The hole in the block must line up with the hole in the crank at about 70 degrees ATDC for full pressure and flow to the rods. If not, it will have issues.

In fact, if you think about it, full groove mains should fix that issue. It will help. To a point. And the groove is there to initiate flow because we all know instantaneous flow is an impossibility.

If this is really the case. Then how much exposure time would the 2 holes have being in alignment at 9000+ rpm.
I think if the upper groove is at stable pressure. That would be more important to constant oil flow through the crank oil drilling’s

The time the holes line up will always be the same. So you're missing the point. If the hole in the block and the hol in the crank DO NOT LINE UP AT THE CORRECT TIME you have an issue.

That's why there is a groove in the upper shell. You've got to get the oil moving, so the groove does that. But those two holes better line up, or you will run over stuff.

Basic hydraulics really.

They always "line up" at some point, and yes, this will be the point of highest pressure, but the small change in placement between manufactures (+/- a few degrees) as you suggest, IS NOT the problem!