Oil system myths

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I have always found it funny that no one worries about that thin metal cover (less than 1/4" thick) held by 1/4" fasteners not having a gasket, but will debate until the end of time about the other side.
 
I have always found it funny that no one worries about that thin metal cover (less than 1/4" thick) held by 1/4" fasteners not having a gasket, but will debate until the end of time about the other side.

Never seen a problem there. But most of my engines were early ones. Better bolts, metallurgy, machining?
 
I have built with and without a gasket with no problems either way. If I have one I use it, if I don't then I don't.

Look at the other side of the pump. That 5 bolt plate on the bottom of the oil pump has no gasket....


Damn, thats why I’m going to post a link to the webinar.

There was plenty of information that was as relevant as what I outlined, but it wasn’t nearly as specific to what we discuss here.

And I kinda forgot about this because it doesn’t usually apply to Chrysler stuff (I happen to have a pump that breaks this sort of rule).

Tim Foster was discussing oil loss at different points in the system, and one was at the pump cover. He basically said that a cast iron cover was the best way to close off the pump, rather than a cheap stamped steel cover or an aluminum one.

The cast iron is more rigid and has built in lubricity, where the others do not. Of course, I have an aluminum cover on my pump because that’s how it’s designed, but it’s not a thin piece either.

I need to listen to it again because there’s a lot of information in it.

I suppose the cover isn’t subject to anywhere near the stress as the body of the pump where it meets the cap.

Just my WAG on that, but he also talked about coatings and things on the stamped covers.
 
Damn, thats why I’m going to post a link to the webinar.

There was plenty of information that was as relevant as what I outlined, but it wasn’t nearly as specific to what we discuss here.

And I kinda forgot about this because it doesn’t usually apply to Chrysler stuff (I happen to have a pump that breaks this sort of rule).

Tim Foster was discussing oil loss at different points in the system, and one was at the pump cover. He basically said that a cast iron cover was the best way to close off the pump, rather than a cheap stamped steel cover or an aluminum one.

The cast iron is more rigid and has built in lubricity, where the others do not. Of course, I have an aluminum cover on my pump because that’s how it’s designed, but it’s not a thin piece either.

I need to listen to it again because there’s a lot of information in it.

I suppose the cover isn’t subject to anywhere near the stress as the body of the pump where it meets the cap.

Just my WAG on that, but he also talked about coatings and things on the stamped covers.

I do wish we could still buy the cast covers with the pickup hole in them. I have been on the lookout for one. They don't seem to pop up for sale very often.

If you post the link, I will put on a pot of coffee and take a good listen.
 
I don't remember for sure, as it was almost 40 years ago. But I do remember making a oil pump to main cap gasket for a 273 engine, I built. I'm thinking I removed a factory gasket, but there was none in the replacement gasket set.

Edit: I just looked at the 1968 Factory parts manual. It shows a oil pump mounting gasket for the slant six, and the big block. It does not list a gasket for 273,318, or 340 engines
65 doesn't show exhaust gasket for 318 poly, and all the B/RB/Hemi but does list a slant and a 273
 
If I'm installing the original oil pump and it came with no gasket, then I don't use a gasket either. If it worked for the XXXXXX miles without one, then the machining surfaces must not be leaking and i like the idea of no gasket to blow out. If I'm installing a different/new pump, then i use the gasket for sure.... with Indian head shellac :)

I believe their thinking on it was the oil pump's in the pan already. If it leaks, it ain't gonna be "much" and it ain't gonna matter.
 
In my opinion, you have to introduce air to have cavitation. Fluid pumps pump fluid, they are not air pumps.
 
Damn, thats why I’m going to post a link to the webinar.

There was plenty of information that was as relevant as what I outlined, but it wasn’t nearly as specific to what we discuss here.

And I kinda forgot about this because it doesn’t usually apply to Chrysler stuff (I happen to have a pump that breaks this sort of rule).

Tim Foster was discussing oil loss at different points in the system, and one was at the pump cover. He basically said that a cast iron cover was the best way to close off the pump, rather than a cheap stamped steel cover or an aluminum one.

The cast iron is more rigid and has built in lubricity, where the others do not. Of course, I have an aluminum cover on my pump because that’s how it’s designed, but it’s not a thin piece either.

I need to listen to it again because there’s a lot of information in it.

I suppose the cover isn’t subject to anywhere near the stress as the body of the pump where it meets the cap.

Just my WAG on that, but he also talked about coatings and things on the stamped covers.

Did they talk about pump impeller/gear designs?

Ive heard there are certain designs more efficient than others.
  • Straight Spur gear vs Gerotor.
  • gear/lobe design: rounded, pointed, helical, number of lobes...
 
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I do wish we could still buy the cast covers with the pickup hole in them. I have been on the lookout for one. They don't seem to pop up for sale very often.

If you post the link, I will put on a pot of coffee and take a good listen.


Good luck finding those. I have 2 Milodon Super Stock oil pans and 2 pick ups that go with them.

One is the static pickup and the other is the swinging unit.

I buy those up as soon as I see them. IMHO, those are the BEST stock chassis oil pans out there.
 
Did they talk about pump impeller/gear designs?

Ive heard there are certain designs more efficient than others.
  • Straight Spur gear vs Gerotor.
  • gear/lobe design: rounded, pointed, helical, number of lobes...


Yes, he covered that and spent some time discussing the new crank driven pumps and their drawbacks.

It was a MUCH better webinar than I expected.
 
Good luck finding those. I have 2 Milodon Super Stock oil pans and 2 pick ups that go with them.

One is the static pickup and the other is the swinging unit.

I buy those up as soon as I see them. IMHO, those are the BEST stock chassis oil pans out there.

I have only seen a few for sale, and someone was quicker hitting the buy it now button than me....

Was it you?!!! Dagnabbit!
 
I have only seen a few for sale, and someone was quicker hitting the buy it now button than me....

Was it you?!!! Dagnabbit!


LOL...IDK it’s been awhile since I’ve found one. Seems like it was at least 5 years ago.

‘In fact, I called and had a LOOOOOOOONG discussion with Milodon about building that pan and pickup again and after about 35 minutes of back and fourth, they said they can’t sell them!

Mil: they just won’t sell.
Me: why not.
Mil: a bunch of rabble that made no sense.
Me: what you said makes NO SENSE. Why won’t it sell?????
Mil: because no one want to put the center link through the pan, and because it’s too low! Chrysler people just will not deal with the centerline through the pan, no matter how much we can show the pan ales more power and has the best oil control of ANY other stock chassis pan out there. It used to be serious street guys could see the benefit to it, but that’s no longer the case today. You can’t explain oil control to most guys today. To them, a pan is a pan, and the least amount of effort to put the engine in the chassis outweighs durability and horsepower.
Me: well that sucks.
Mil: it’s the reality with Chrysler consumers today. And, even though that pan is not any lower than any other comparable pan, it’s rear sump makes it less susceptible to dragging the ground, unless the car is running 22 inch tall front tires or the car is dragging the chassis.
Me: I was born into the wrong generation.

That’s a quick paraphrase of the end of that conversation. Like many things, Chrylser guys just will not get out of their comfort zone. They use whatever the mass claims they use, or whatever is the easiest to install, falling back into the 1980’s and even earlier technology because that is the least path of resistance.
 
One of the biggest misconceptions when it comes to centrifugal pumps is that water or oil in a engine is “sucked” out of the oil pan or radiator. Which isn’t possible, what actually occurs is the is a pressure drop created by the impeller of a WP or in the case of a oil pump the rotation of the gears creates a lower pressure on the intake side of the pump which causes fluid to travel to a higher pressure. Atmospheric air pressure is 14.7 at sea level. It’s easier to understand it when you stick a straw in your glass of water or soda, when you “suck” on a straw, it travels up the straw because with your mouth you have lower the pressure on the suction side causing the fluid to travel up the straw. Unless your talking about positive displacement pumps which is a different animal.
but an oil pump in an engine isn't a centrifugal pump. it works by 'trapping oil in cavities which decrease in size as the rotors turn and then is released at the outlet port at greater pressure.
a centrifugal pump has a rotor spinning in a cavity and centrifugal force pushes the (usually) water to the outside of the cavity where the outlet is. up to a point a centrifugal pump can be dead headed (when a radiator is blocked for example) and it would cavitate whereas an oil pump if you did that would most likely break it's driveshaft.
neil.
 
Cavitation can only occur in any oil pump water pump even up to and including a fire pump on a fire truck if you exceed the supply. If the pump gears or impellers are not damaged. Using a heavier weight oil will certainly use more power to pump.
I had a long conversation with an engineer from aeromotive yesterday about this very topic. Please elaborate on this. In my opinion you can cavitate a pump even with unlimited supply. Think of a boat propeller. Unlimited supply. Cavitation happens because of pressure differential lowering the vaporization point (boiling point) of whatever medium you are pumping, be it water, fuel, or oil, to its flash point. Add restriction to the supply side (increased vacuum, ie negative pressure) or heat in to the medium and it only gets worse.
 
Damn, thats why I’m going to post a link to the webinar.

There was plenty of information that was as relevant as what I outlined, but it wasn’t nearly as specific to what we discuss here.

And I kinda forgot about this because it doesn’t usually apply to Chrysler stuff (I happen to have a pump that breaks this sort of rule).

Tim Foster was discussing oil loss at different points in the system, and one was at the pump cover. He basically said that a cast iron cover was the best way to close off the pump, rather than a cheap stamped steel cover or an aluminum one.

The cast iron is more rigid and has built in lubricity, where the others do not. Of course, I have an aluminum cover on my pump because that’s how it’s designed, but it’s not a thin piece either.

I need to listen to it again because there’s a lot of information in it.

I suppose the cover isn’t subject to anywhere near the stress as the body of the pump where it meets the cap.

Just my WAG on that, but he also talked about coatings and things on the stamped covers.
i guess you could install a second stamped steel cover plate with longer bolts.
neil.
 
but an oil pump in an engine isn't a centrifugal pump. it works by 'trapping oil in cavities which decrease in size as the rotors turn and then is released at the outlet port at greater pressure.
a centrifugal pump has a rotor spinning in a cavity and centrifugal force pushes the (usually) water to the outside of the cavity where the outlet is. up to a point a centrifugal pump can be dead headed (when a radiator is blocked for example) and it would cavitate whereas an oil pump if you did that would most likely break it's driveshaft.
neil.
Not true, how does the oil get from the pan to the pump? It is not a positive displacement pump. You can’t reach in a bucket and pick up oil with your hand no more than you can water. They don’t have enough surface tension. It is not gravity fed.
 
That includes "just about" the entire Mopar Performance catalog. Pitiful, ain't it?

When I worked in a car quest in the eighties, the owner was a hot rodder. He still loves early Hemis. He let me get parts at cost provided I didn't supply my buddies. I wish I would have bought, bought, bought! Sometimes it doesn't pay to be a tightwad.
 
When I worked in a car quest in the eighties, the owner was a hot rodder. He still loves early Hemis. He let me get parts at cost provided I didn't supply my buddies. I wish I would have bought, bought, bought! Sometimes it doesn't pay to be a tightwad.
In the eighties and early 90's I found every awesome deal I couldn't afford that everyone with money wished they could find :D
 
Well, that is the thing, it's an opinion.
I have seen a propeller in water cavitate, and it sure looked like air to me.
 
In my opinion, you have to introduce air to have cavitation. Fluid pumps pump fluid, they are not air pumps.
Talk to a submariner.....Cavitation of the prop underwater is like telling the world your here in a permanent hide and seek environment. its the boiling of water at the tip of the props due to the negative pressure they create, lower boiling point at lower pressures. Not sure what the vacuum pressure of an oil pump is so its probably not an issue with an oil pump but the blanket term you need air to cavitate is not correct.
 
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