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Oil pressure vs volume

General engine tech -- Drag Racing to Circle Track

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piston guy
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Re: Oil pressure vs volume

Post by piston guy » Wed May 20, 2020 11:57 am

Steve,
On my original aluminum block ( pass side lifter bushings only , main bearing restrictors) and I ran a std pump with the Ford /G&R high pressure spring. Oil pressure "at rpm" was always 60+ with aluminum rods. The pan was the Moroso "pro stock" pan. Cold pressure was always in the 80-90 range. My new RDI 302 aluminum block will be a new learning experience.

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Re: Oil pressure vs volume

Post by Steve.k » Wed May 20, 2020 12:08 pm

So you had to do those mods to get the pressure?

GLHS60
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Re: Oil pressure vs volume

Post by GLHS60 » Wed May 20, 2020 12:20 pm

Very well said, my pal Mark knows Engines!

One can certainly depend on him come up with a thought provoking analogy.

Thanks
Randy

Mark O'Neal wrote:
Wed May 20, 2020 12:07 am
Pressure is what blew the filter off the Engine.

Volume is what determined how long it took to clean it up.
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There is no logical reason to call an Engine a motor.

tuffxf
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Re: Oil pressure vs volume

Post by tuffxf » Wed May 20, 2020 5:58 pm

G,day Steve,
do you know cam bearing and lifter - bore clearances?
What i did when going to a roller cam was to have the have the engine on the engine stand with pan, rocker covers and intake off.
put the pan on floor or box, level so you have access to see what is going on , take the pickup tube out of the pump and put a npt - -12 jic nipple in its place and make up a -12 hose as a temp pick up and place in the pan at correct height off the floor.
You will have a priming tool you can run with a decent drill
to make it real, you need to work out what the viscosity of your oil of choice is at the operating temp you are running, easy to work out.
Then buy some lighter weight oil that matches that viscosity at room temp, it will be real light, i used thinner oil plus my pan heater to achieve what i wanted.
jam a mechanical gauge on it
Next step is important!
crack a beer or make a rum, preferred! you will need it.
Run the thing on the drill and be prepared to make a bit of a mess, you will be able to see any obvious pouring of oil or volume loss issues,
pay attention to what is coming out above and below the lifter bores, out the lifter axle lube,front of the cam / cam gear area, take note of what the gauge is telling you.
Then for an interesting experiment for yourself, rip the roller lifters out of it and drop a set of flat tappet lifters into the bores and repeat.
Then make another rum when you see the difference!
Huge difference in oiling and sizing between different lifters.
It is really only a small amount of work but it will answer a lot of questions and point you in the directions that need addressing.
Cheers
Paul

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Re: Oil pressure vs volume

Post by Mark O'Neal » Wed May 20, 2020 6:22 pm

Coloradoracer wrote:
Wed May 20, 2020 9:12 am
tenxal wrote:
Wed May 20, 2020 7:38 am
How is the bypassed oil being handled?
That depends on the pump. Some pumps will dump the bypassed oil back to pan, others will redirect it back to the inlet....

Or...as mentioned earlier.....it shoots the filter across the shop and dumps 5 quarts on the floor.

To my never ending amusement.

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Re: Oil pressure vs volume

Post by tenxal » Wed May 20, 2020 7:03 pm

Coloradoracer wrote:
Wed May 20, 2020 9:12 am
tenxal wrote:
Wed May 20, 2020 7:38 am
How is the bypassed oil being handled?
That depends on the pump. Some pumps will dump the bypassed oil back to pan, others will redirect it back to the inlet....
Yeah...I know. :wink:

I don't see where the O.P. has discussed it, other than to state what pump is on it.

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Re: Oil pressure vs volume

Post by Steve.k » Wed May 20, 2020 7:07 pm

Melling dumps back to inlet side I believe.

Kevin Johnson
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Re: Oil pressure vs volume

Post by Kevin Johnson » Wed May 20, 2020 9:22 pm

Steve.k wrote:
Wed May 20, 2020 7:07 pm
Melling dumps back to inlet side I believe.
Yes, you can see a series of pictures of the basic pump body here -- no external relief opening so an internal bypass:

https://www.jegs.com/i/Melling/689/M84AHV/10002/-1#

Aside: If you are using the stock pickup head then it is a poor design with respect to anti-vortexing. It is better than a free standing hemispherical bulb, yes. Look to the Nissan VG30DETT pickup tube head.
mel-84-as1_w.jpg





VG30DETT
VG30DETT.jpg
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Re: Oil pressure vs volume

Post by blykins » Thu May 21, 2020 9:10 am

Where were you measuring the oil pressure? It makes a difference if it's at the front of the block near the pump or at the rear of the block.

FWIW, here's the bearings from my 354C, which had a standard pressure/volume pump on it. Were seeing about 60 psi at the rear of the block, pulling to 8500 rpm. Standard main bearings, coated rod bearings, can still see my mic tracks. 620 hp.

Image

Image
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Re: Oil pressure vs volume

Post by Steve.k » Thu May 21, 2020 9:32 am

Oil pressure feed is standard location. Its a custom kevko piickup to fit pan. Last dyno session before this our bearings looked the same.

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Re: Oil pressure vs volume

Post by blykins » Thu May 21, 2020 10:32 am

I think you're in good shape.
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Re: Oil pressure vs volume

Post by Steve.k » Thu May 21, 2020 10:47 am

B9C095C3-7AB8-4718-83EF-2A80DCE284A9.jpeg
4975EAB2-D27B-4897-9CEE-7B6114E5CF8E.jpeg
Kevin Johnson wrote:
Wed May 20, 2020 9:22 pm
Steve.k wrote:
Wed May 20, 2020 7:07 pm
Melling dumps back to inlet side I believe.
Yes, you can see a series of pictures of the basic pump body here -- no external relief opening so an internal bypass:

https://www.jegs.com/i/Melling/689/M84AHV/10002/-1#
Theres pickup tube.
Aside: If you are using the stock pickup head then it is a poor design with respect to anti-vortexing. It is better than a free standing hemispherical bulb, yes. Look to the Nissan VG30DETT pickup tube head.

mel-84-as1_w.jpg






VG30DETT
VG30DETT.jpg
You do not have the required permissions to view the files attached to this post.

Kevin Johnson
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Re: Oil pressure vs volume

Post by Kevin Johnson » Thu May 21, 2020 11:16 am

Thank you!
Steve.gif
Steve 2.gif

Edit 2: Other interesting flow is set up beneath tray but the above seems to be an issue in my 'noggin. The leading edge of the tray directs flow smack down the smooth pan wall. The louvers there immediately adjacent reinforce this.
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Last edited by Kevin Johnson on Thu May 21, 2020 11:48 am, edited 3 times in total.

piston guy
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Re: Oil pressure vs volume

Post by piston guy » Thu May 21, 2020 11:38 am

Steve.k wrote:
Wed May 20, 2020 12:08 pm
So you had to do those mods to get the pressure?
It was standard practice in the late 70's and was already done when I bought the complete engine. I did not build it , I only rebuilt/maintained it after I got it.

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Re: Oil pressure vs volume

Post by Steve.k » Thu May 21, 2020 12:49 pm

Kevin Johnson wrote:
Thu May 21, 2020 11:16 am
Thank you!

Steve.gif

Steve 2.gif


Edit 2: Other interesting flow is set up beneath tray but the above seems to be an issue in my 'noggin. The leading edge of the tray directs flow smack down the smooth pan wall. The louvers there immediately adjacent reinforce this.
So Kevin you think there could be some ariation issues set up this way? Maybe im better off without windage tray.

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