Low oil pressure?

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What timing are you talking about YR rod feed timing
I've had customers who had me drill the front of SBC for front end feed- mostly sprinters and road/ circle track I have/ had a jig for it
I've fed the mains from the side where the bearing halves join
I've put the pressure relief at the opposite end of the block from the pump
lots of things
good points


Yes, rod feed timing. The rest of it will take care of itself. You can put the oil in anywhere you want. As long as the oil timing is correct it will oil. The rest is smoke and mirrors.

I'm not a fan of running two columns of oil at each other. You can have pressure and no flow. I've run into it myself.
 
In the late 70's I had a AAR and my friend had a 69 440 6 pack coronet R/T. We lived around Akron and knew Arlen Vanke and Larry Shepard and a few other mopar racers, and we used to drive down to Shepard's shop and BS with Larry sr and see how much we could learn about race engines as he always had a few hemi's around and he told us that he wrote the books on hemi's, he was a very smart guy, I understood he was a engineer for chrysler and my dad worked there starting in 57 and I think Shepard was about the same age as my dad and Larry jr is about the same age as me but any way it got me thinking reading this post and I did a little searching and found this.
Larry Shepard | Michigan Motor Sports Hall of Fame
Now would the real Larry Shepard please stand up!
 
Yes, rod feed timing. The rest of it will take care of itself. You can put the oil in anywhere you want. As long as the oil timing is correct it will oil. The rest is smoke and mirrors.

I'm not a fan of running two columns of oil at each other. You can have pressure and no flow. I've run into it myself.

Full groove main's will oil the rods full time, right, wrong ?

As long as you have a leak the oil wont stop ?
 
Full groove main's will oil the rods full time, right, wrong ?

As long as you have a leak the oil wont stop ?


Full groove bearings do send oil to the rods all the time, and IMO that's good for a Chrysler with Chrysler oil timing.

The issue is you need full pressure and full flow to the rods when the piston is about ~70* ATDC. By the time a Chrysler has the piston that far down the hole the full pressure, full flow oil is long past that. The Chrysler has full pressure, full flow oil to the rods too soon.
 
Back in the day we ran half grove bearings- Vandervell etc because you loose a lot of bearing support with the grove- I think maybe 30%- you loose oil film near the edges of the bearing and half grove have twice as many edges as well as the groove
We found that quick and dirty cross drilling was not the answer
and some smart crank guys figured out oiling drillings that work much better
There is a graphic for inline which shows where you want to inject oil for best oil film- hydrodynamic wedge
when converting to V8 you have to consider both banks and the fact that two cylinders fire next to each other
one reason we grooved the blocks bearing bore with a tool that rotates with the main C/L but has a cutter on the eccentric- think like a crank throw with teeth
That puts the oil in the trough by the parting line and you do not loose oil where the big clearance is at the old oil feed location at the top- worst spot to feed a main

70 ATDC is closer to where the rod is tangent to the crank throw than 90 degrees close to where there is the most cylinder wall pressure
you get the most mechanical advantage at the tangent point
a long rod is at more degrees ATDC than a short rod another reason why each takes a different cam
 
Back in the day we ran half grove bearings- Vandervell etc because you loose a lot of bearing support with the grove- I think maybe 30%- you loose oil film near the edges of the bearing and half grove have twice as many edges as well as the groove
We found that quick and dirty cross drilling was not the answer
and some smart crank guys figured out oiling drillings that work much better
There is a graphic for inline which shows where you want to inject oil for best oil film- hydrodynamic wedge
when converting to V8 you have to consider both banks and the fact that two cylinders fire next to each other
one reason we grooved the blocks bearing bore with a tool that rotates with the main C/L but has a cutter on the eccentric- think like a crank throw with teeth
That puts the oil in the trough by the parting line and you do not loose oil where the big clearance is at the old oil feed location at the top- worst spot to feed a main

70 ATDC is closer to where the rod is tangent to the crank throw than 90 degrees close to where there is the most cylinder wall pressure
you get the most mechanical advantage at the tangent point
a long rod is at more degrees ATDC than a short rod another reason why each takes a different cam


I'm sorry, but there's enough wrong in this that I'm not going to try and fix it.
 
Sanborn was wrong then, and is wrong now. I to,d him way back when I was on mofartcrap.

If you can't understand the simple physics that have been worked out for decades, I can't help you. You can move the oil supply anywhere you want and it won't make a pinch of **** difference.

It isn't a supply issue. It isn't an oil velocity issue. It's an oil timing issue. You can argue the point all you want, and you will still be wrong.

I've been there. I've done that. I've made over 2 hp/CID at 8500 and the stock system is plenty. If you correct the oil timing. All that other **** is a waste of time and money.

Sanborn was wrong. I sent him several emails with pictures. And he always said my way works. But he never turned the RPM I did.

Fix your oil timing. Don't **** with that other stuff. It's stupid. If you would have looked at a SBC block and crank like I said, you'd see how far off the timing is.
Yellow rose take it easy lol I agreed with you about the timing.
I just think there is a different way to fix it than you did.
 
Yellow rose take it easy lol I agreed with you about the timing.
I just think there is a different way to fix it than you did.


I've broken enough parts to know for a fact that oil timing is what it is. It's been settled science for decades. Hell, I think it was settled between the wars. Maybe before.

As long as the hole in the main journal of the crank is lined up with the feed hole in the block at about 70 degrees after TDC it doesn't matter where that oil feed hole is located. It can be anywhere in the circle, within reason. You have to be able to drill the passage from the main out to the rod.

It's a constant flow system. Rod length makes ZERO difference.

I'm surprised more people don't know this. It's why Chrysler's, Buicks, Olds and Pontiacs don't oil very well at higher RPM's. Look at their oil timing.
 
I've broken enough parts to know for a fact that oil timing is what it is. It's been settled science for decades. Hell, I think it was settled between the wars. Maybe before.

As long as the hole in the main journal of the crank is lined up with the feed hole in the block at about 70 degrees after TDC it doesn't matter where that oil feed hole is located. It can be anywhere in the circle, within reason. You have to be able to drill the passage from the main out to the rod.

It's a constant flow system. Rod length makes ZERO difference.

I'm surprised more people don't know this. It's why Chrysler's, Buicks, Olds and Pontiacs don't oil very well at higher RPM's. Look at their oil timing.
Agreed but it seems to me that the size of the hole in the bearing shell is much smaller than that counter bore in the bearing saddle.
If you slot the bearing shell as Sanborn does and Guitar jones does, you shift the degrees of rotation closer to that 70 degree position that you feel is ideal. The slotted bearing shell along with the counter bore
Extends the position where the crank oil passage can get pressurized oil. IMHO both these guys are doing this mod with apparent success.
I believe rightly or wrongly that this modification is adjusting the oil timing. Either my 69 340 block missed some machining operations back in 1969 or Chrysler made a running change and started adding those counter bores. We are way off topic in this thread. Lol
 
I don't understand the oil line in the valley mod it makes no sense to me, I would block off the oil to the left side if it has solid lifters and that would give more oil to the mains, the lifters get drain back oil from the top and oil from the rods from the bottom there is no lack of oil.
 
I don't understand the oil line in the valley mod it makes no sense to me, I would block off the oil to the left side if it has solid lifters and that would give more oil to the mains, the lifters get drain back oil from the top and oil from the rods from the bottom there is no lack of oil.
I used to do it that way. Works fine for regular roller lifters.
Are you referring to the crossover line for improved main oiling or the new one for better rocker arm oiling?
 
The old one for better main oiling, supposedly. never liked it, who ever thought it up didn't understand it.

And the rocker arms oil from the cam not the galleys.
 
The old one for better main oiling, supposedly. never liked it, who ever thought it up didn't understand it.

And the rocker arms oil from the cam not the galleys.
The inventor of the w2 head invented that. Bob Mullen I believe.
I believe it works but I do not like it because I think it is too difficult to do properly for diy person.
 
The old one for better main oiling, supposedly. never liked it, who ever thought it up didn't understand it.

And the rocker arms oil from the cam not the galleys.
In the stroker small block book there is another type crossover line recommended that is used to oil the rockers and do away with oiling them from the cam. That's why I said which crossover line.
 
It was Bob Mullen
As YR intimates the grove in the bearing is not enough to feed the crank/ rods
 
The inventor of the w2 head invented that. Bob Mullen I believe.
I believe it works but I do not like it because I think it is too difficult to do properly for diy person.
.
I thought it was Larry Atherton.
 
I've broken enough parts to know for a fact that oil timing is what it is. It's been settled science for decades. Hell, I think it was settled between the wars. Maybe before.

As long as the hole in the main journal of the crank is lined up with the feed hole in the block at about 70 degrees after TDC it doesn't matter where that oil feed hole is located. It can be anywhere in the circle, within reason. You have to be able to drill the passage from the main out to the rod.

It's a constant flow system. Rod length makes ZERO difference.

I'm surprised more people don't know this. It's why Chrysler's, Buicks, Olds and Pontiacs don't oil very well at higher RPM's. Look at their oil timing.
I'll agree on the 'this stuff has been known for a long time'.... there are many things like that; cellular antenna engineers 'discovered' the 'miracle' of certain antenna pattern tweaks in the late 90's..... almost 60 years after WWII radar engineers started using it LOL.

"It can be anywhere in the circle, within reason." YR, which 'circle' are you speaking of? The rod bearing end of the oiling passage?

But I am still trying to figure out the point of the 70 degree ATDC timing of oiling the rods. Is the force on the rod bearing approaching it's peak at that crank angle, possibly due to the next firing cylinder nearing maximum compression pressure and adding to the combustion pressure already acting directly on the rod ? This 70 ATDC matter is still mystifying me.

Here is an interesting article that discusses the Chevy oiling situation.
Tech Talk #51 – Crank Calls, Part II

It talks about the main-to-rod oil passages basically not going straight through the center of the main but at an angle that is rather flat to the main journal's surface, so that centrifugal force does not cancel as much of the supply oil pressure, due to the oil in rod oiling passage right at the main journal wanting to be thrown backwards.

This also refers to oiling timing as an improvement, not as the key. So which is more important is not yet clear to me. If this centrifugal force is the reason, then it's easy to see why this becomes more important when you go from short spurts of 6500 RPM max, versus long runs at 8500 RPM. And I better see why one would want higher oil pressures than for 'standard' use with high revving engines.
 
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WE had Bob doing some race car heads about the time he was workin on his version of the W2
I'm sure there were other prototypes because not all of Bob's ideas made it into the final castings
Bob did awesome Hemi heads for the timeframe- worked especially well at Riverside Raceway
(Where we won with our Matador)
 
YR
maybe it's just a coincidence that 70 degree area is where you are getting maximum pressure on the cylinder wall (later with a long rod)
Thanks for the opportunity to rethink this
 
I'll agree on the 'this stuff has been known for a long time'.... there are many things like that; cellular antenna engineers 'discovered' the 'miracle' of certain antenna pattern tweaks in the late 90's..... almost 60 years after WWII radar engineers started using it LOL.

"It can be anywhere in the circle, within reason." YR, which 'circle' are you speaking of? The rod bearing end of the oiling passage?

But I am still trying to figure out the point of the 70 degree ATDC timing of oiling the rods. Is the force on the rod bearing approaching it's peak at that crank angle, possibly due to the next firing cylinder nearing maximum compression pressure and adding to the combustion pressure already acting directly on the rod ? This 70 ATDC matter is still mystifying me.

Here is an interesting article that discusses the Chevy oiling situation.
Tech Talk #51 – Crank Calls, Part II

It talks about the main-to-rod oil passages basically not going straight through the center of the main but at an angle that is rather flat to the main journal's surface, so that centrifugal force does not cancel as much of the supply oil pressure, due to the oil in rod oiling passage right at the main journal wanting to be thrown backwards.

This also refers to oiling timing as an improvement, not as the key. So which is more important is not yet clear to me. If this centrifugal force is the reason, then it's easy to see why this becomes more important when you go from short spurts of 6500 RPM max, versus long runs at 8500 RPM. And I better see why one would want higher oil pressures than for 'standard' use with high revving engines.
There is an entire thread /discussion that we had on this topic on the board. You can read yellow rose views on the issue. There are pics posted there showing a chev crank versus the Chrysler small block oiling holes. I agree with yellow rose on the timing issue because I make crankshafts for a living at Chevrolet and I know the position of the holes is very precisely located. However I do not agree with his views on how to improve the timing by cross drilling. Hence the Rehr Morrison article explaining why. But I believe that slotting the bearing shells improves the timing as well as increases the dwell time that the crank has full pressure. Ironically Mopar performance used to sell slotted bearings many years ago.
A friend yesterday tipped me to a very good discussion on small block oiling over on the class racer forum. 360 mopar oiling issue - CLASS RACER FORUM
 
There is an entire thread /discussion that we had on this topic on the board. You can read yellow rose views on the issue. There are pics posted there showing a chev crank versus the Chrysler small block oiling holes. I agree with yellow rose on the timing issue because I make crankshafts for a living at Chevrolet and I know the position of the holes is very precisely located. However I do not agree with his views on how to improve the timing by cross drilling. Hence the Rehr Morrison article explaining why. But I believe that slotting the bearing shells improves the timing as well as increases the dwell time that the crank has full pressure. Ironically Mopar performance used to sell slotted bearings many years ago.
A friend yesterday tipped me to a very good discussion on small block oiling over on the class racer forum. 360 mopar oiling issue - CLASS RACER FORUM



I only advocate cross drilling a crank to correct the oil timing.

Since you drill cranks for a living, maybe you can shed some light on things pertaining to the oil feed passages in the crank.

If you take a SBC and a SBM crank and lay them side by each, you'll see that they are drilled exactly the same. If you look at the SBC block you'll notice (talking OE stuff here not the later stuff with priority main oiling but it's essentially the same) the oil feed hole in the block is at 12 o'clock looking from the front at the number one main bearing bore.

If you do the math, you'll find that the oil feed hole in the block lines up perfectly with the oil hole in the main journal and the piston would be about 70 degrees ATDC. That is full flow and full pressure to the rod, where peak load is.

Now look at a SBM. I don't have one right in front of me but from memory, the oil feed hole in the blow isn't at 12 o'clock. It's closer to 11:30 or maybe even 11:15 (I used to know how many degrees it was but its slipped my mind but the point is still made) which means, that full flow and full pressure to the rod bearings was too early, long before 70 degrees ATDC. This is because the oil feed hole in the main bearing is in exactly the same location as the SBC crank. If you could rotate the oil feed hole backwards, towards the 11 o'clock position, you would delay full flow and full pressure to the rods until about 70 degrees ATDC.

I've asked everyone from Callie's, Scat, Winberg and one other I forget, and they all said they same thing...you can't move the oil feed hole in the main journal that far back and get it to line up with the correct location on the rod throw.

Is this making sense? It's well established you need full oil at about 70 degrees ATDC. There should be no questions on that. The question becomes how do you make that happen on a small or big block MoPar short of Chrysler changing the oil feed holes in the block, which they did much later on in the R block series, where the adopted a priority main oiling system.

The best answer I've found is to block ALL the oil going to the mains from the passenger side oil gallery. All of it. Doesn't matter how it's done, it needs to be done. A simple set screw in the oil feed gallery from the number 1 main to the drivers side oil gallery will stop oil going there, as you don't need it.

The next step is to drill main caps 1-4 down through the center of the cap, so when the cap is installed, there will be a hole though the cap at the 6 o'clock position. Then, I made some changes to how this was done on the first engine I had. The guy who originated the fix drill a hole in the number 5 main cap on the passenger side directly into the feed passage that eventually leads to the filter. Doing it this way works, but you don't filter the oil going to the mains. The oil going other places gets filtered. So eventually all the oil gets filtered. Then, he made up a right angle fitting that screwed in to the cap. And from there he drilled 4 holes for 1/8 pipe and ran hoses from that common feed to the main bearing caps.

The last thing to do was cross drill the crank. Why? Because the oil timing would still be wrong if you are feeding oil at 6 o'clock but there was no hole in the main journal. In fact, it would be worse that what Chrysler did. Cross drilling simply relocated the feed hole in the main bearing with full pressure, full flow oil at the correct time. I should mention that you have to drill a hole in the lower main bearing shell and use full groove bearings. That way, you initiate flow before the holes line up.

You have now corrected the oil timing. It's simple to hide the system in the pan as it was done when I bought the engine. No one knew what was done. And it worked.

I eventually got tired of seeing trash in the bearings becaus they were getting unfiltered oil. So instead of a 1 inch diameter feed manifold in the pan coming off the main cap, I moved all that crap outside the pan. This also allowed me to run an externally adjustable pressure regulator on the system.

What I did was take a 3 inch diameter piece of aluminum tube about 8 inches long and welded a lid on both ends. On top, I welded in a number 10 fitting, and on the bottom I used 5 number 4 fittings.

Now, I ran the oil out of the block, through my Systems 1 oil filter, out of the filter to the top of my new, bigger manifold, and the five hoses fed each main. 1-4 going through the pan with bulkhead fittings and number 5 being fed right back into the block. I installed my external pressure regulator after the filter and could adjust the pressure to virtually anything I needed. And, all the oil to the bearings was filtered before it went to them.

That, in a nutshell is how I corrected the oil timing. I didn't design it. I just updated it a bit. If you want to turn 8500 and make power doing it, it's what you have to do. No other bullshit works.

So...my question for Duane is...can you move the oil feed hole in the main bearing journal backwards far enough so the oil holes line up at the correct time? With out throwing off the feed hole in the rod? I was always told no, because to me that would be an easier fix.

What do you think Duane?
 
Thanks YR. making sense now. The effort is appreciated, and your long post will be read multiple times at this end.

I just checked a 360 main bearing..... the main feed hole is 10 degrees off from being straight up, towards the passenger side. You would have to move that hole just about 1/4" towards the driver's side to get it to be at 12 o'clock. so if the SBM crank is drilled at exactly the same place as the SBC that seems like it would equalize things pretty well. Would a slot in the main web 1/4' long weaken things a whole lot? Guess I need to look.

One thing I think you did YR that probably made another difference: bypassing the regular system for oiling the mains and going direct. I suspect you ended up with better oil pressure to the mains after that change which helped too. So how much a 10 degree timing change and a better oil feed did the trick, seems hard to separate out.

A friend yesterday tipped me to a very good discussion on small block oiling over on the class racer forum. 360 mopar oiling issue - CLASS RACER FORUM
Thank you; I'll look at this for sure.

Now the next question: At what RPM does this become essential? And below what RPM is it a waste of time?
 
I only advocate cross drilling a crank to correct the oil timing.

Since you drill cranks for a living, maybe you can shed some light on things pertaining to the oil feed passages in the crank.

If you take a SBC and a SBM crank and lay them side by each, you'll see that they are drilled exactly the same. If you look at the SBC block you'll notice (talking OE stuff here not the later stuff with priority main oiling but it's essentially the same) the oil feed hole in the block is at 12 o'clock looking from the front at the number one main bearing bore.

If you do the math, you'll find that the oil feed hole in the block lines up perfectly with the oil hole in the main journal and the piston would be about 70 degrees ATDC. That is full flow and full pressure to the rod, where peak load is.

Now look at a SBM. I don't have one right in front of me but from memory, the oil feed hole in the blow isn't at 12 o'clock. It's closer to 11:30 or maybe even 11:15 (I used to know how many degrees it was but its slipped my mind but the point is still made) which means, that full flow and full pressure to the rod bearings was too early, long before 70 degrees ATDC. This is because the oil feed hole in the main bearing is in exactly the same location as the SBC crank. If you could rotate the oil feed hole backwards, towards the 11 o'clock position, you would delay full flow and full pressure to the rods until about 70 degrees ATDC.

I've asked everyone from Callie's, Scat, Winberg and one other I forget, and they all said they same thing...you can't move the oil feed hole in the main journal that far back and get it to line up with the correct location on the rod throw.

Is this making sense? It's well established you need full oil at about 70 degrees ATDC. There should be no questions on that. The question becomes how do you make that happen on a small or big block MoPar short of Chrysler changing the oil feed holes in the block, which they did much later on in the R block series, where the adopted a priority main oiling system.

The best answer I've found is to block ALL the oil going to the mains from the passenger side oil gallery. All of it. Doesn't matter how it's done, it needs to be done. A simple set screw in the oil feed gallery from the number 1 main to the drivers side oil gallery will stop oil going there, as you don't need it.

The next step is to drill main caps 1-4 down through the center of the cap, so when the cap is installed, there will be a hole though the cap at the 6 o'clock position. Then, I made some changes to how this was done on the first engine I had. The guy who originated the fix drill a hole in the number 5 main cap on the passenger side directly into the feed passage that eventually leads to the filter. Doing it this way works, but you don't filter the oil going to the mains. The oil going other places gets filtered. So eventually all the oil gets filtered. Then, he made up a right angle fitting that screwed in to the cap. And from there he drilled 4 holes for 1/8 pipe and ran hoses from that common feed to the main bearing caps.

The last thing to do was cross drill the crank. Why? Because the oil timing would still be wrong if you are feeding oil at 6 o'clock but there was no hole in the main journal. In fact, it would be worse that what Chrysler did. Cross drilling simply relocated the feed hole in the main bearing with full pressure, full flow oil at the correct time. I should mention that you have to drill a hole in the lower main bearing shell and use full groove bearings. That way, you initiate flow before the holes line up.

You have now corrected the oil timing. It's simple to hide the system in the pan as it was done when I bought the engine. No one knew what was done. And it worked.

I eventually got tired of seeing trash in the bearings becaus they were getting unfiltered oil. So instead of a 1 inch diameter feed manifold in the pan coming off the main cap, I moved all that crap outside the pan. This also allowed me to run an externally adjustable pressure regulator on the system.

What I did was take a 3 inch diameter piece of aluminum tube about 8 inches long and welded a lid on both ends. On top, I welded in a number 10 fitting, and on the bottom I used 5 number 4 fittings.

Now, I ran the oil out of the block, through my Systems 1 oil filter, out of the filter to the top of my new, bigger manifold, and the five hoses fed each main. 1-4 going through the pan with bulkhead fittings and number 5 being fed right back into the block. I installed my external pressure regulator after the filter and could adjust the pressure to virtually anything I needed. And, all the oil to the bearings was filtered before it went to them.

That, in a nutshell is how I corrected the oil timing. I didn't design it. I just updated it a bit. If you want to turn 8500 and make power doing it, it's what you have to do. No other bullshit works.

So...my question for Duane is...can you move the oil feed hole in the main bearing journal backwards far enough so the oil holes line up at the correct time? With out throwing off the feed hole in the rod? I was always told no, because to me that would be an easier fix.

What do you think Duane?
I never put a degree wheel on to check how many degrees of rotation there was, but when we had this discussion about timing,
I was also reading guitar jones thread about slotting the bearings, and Charles Sanborns thread where he also slots the bearings.
I also was in the middle of assembling my own new motor.
I wanted to slot my bearings as well. This was the first time I have performed that mod. I had a friend wire edm the slots and I had tell him exactly what I wanted. Looking at where the original oil hole was in the bearing shell you are 100% correct the hole is not at 12 o'clock
More like 11:30 just as you say. But the counter bore is pretty much in the centre of the saddle. The original hole in the bearing shell is also at 11:30. So it became obvious that there is only one logical direction to go with the slot. Towards the 12 o'clock position and if memory serves if you make the slot to 1/2 inch length you are probably over to the 12:30 position.
My point about the counterbore in the saddle is that slotting the bearings would be pointless if the counterbore was not there to allow the oil flow over to the slotted position.
That's when it hit me that the reason slotting the bearing is claimed to be so beneficial is because you have improved that oil timing.
Now you can get full flow and pressure all the way from 11:30 to
The 12:30 position. The oil can flow underneath the bearing shell
All the way over to 12:30 position with full flow and pressure.
If my memory serves that counterbore overlaps the cam bearing feed hole that is at the 12:00 position.
As I said I 100% agree with what you say about the timing.
It would be very hard to fix the timing in the crankshaft. Those gun drills already come in at extreme angles on a round surface.
I suspect imho that Chrysler addressed the issue in the block with a running change and added that counterbore. Slotting the bearings imho just utilizes it.
But I could be wrong lol.
The sbm has much room for improvement in its oiling.
Hope I explained that clearly.
 
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