Proper Oil PSI

67topless

67topless

Member
Mar 31, 2006
203
0
16
Raleigh, NC
#1
I saw in another thread "GOT THE CAR DONE AT APRIL 3, 2006 11:50PM!!!!!!!!" by 69Rcode_Mach1 that he mentioned he is at 60 PSI and there were some comments mentioning that was high. Ouch... when my engine is cold, I am running closer to 75 PSI, if not a little higher. In addition, when it is hot at ~ 190 degrees, I am still anywhere around 40 PSI at idle. I am using a high volume oil pump... but is this something that is all right, or do I need to address this pressure.

289 with Comp Cams Aluminum Roller Rockers - Comp Cams Hydraulic Lifters - Comp Cams Xtreame Energy cam

Holley 4160 600 CFM - Edelbrock 289 Performer - Hooker Competition headers

Also using Valvoline 10w 30 weight

Thank you for your input,

Scott
 
#2
67topless said:
I saw in another thread "GOT THE CAR DONE AT APRIL 3, 2006 11:50PM!!!!!!!!" by 69Rcode_Mach1 that he mentioned he is at 60 PSI and there were some comments mentioning that was high. Ouch... when my engine is cold, I am running closer to 75 PSI, if not a little higher. In addition, when it is hot at ~ 190 degrees, I am still anywhere around 40 PSI at idle. I am using a high volume oil pump... but is this something that is all right, or do I need to address this pressure.

289 with Comp Cams Aluminum Roller Rockers - Comp Cams Hydraulic Lifters - Comp Cams Xtreame Energy cam

Holley 4160 600 CFM - Edelbrock 289 Performer - Hooker Competition headers

Also using Valvoline 10w 30 weight

Thank you for your input,

Scott
Click to expand...

Your oil pressure is wonderful and you don't need to do anything. Many of us wish we could have pressure like that. You could have easily gotten away with a standard pressure pump instead of the HV. All that you are doing is loosing a tiny bit of HP from the extra load, no biggy.
 
#3
67topless said:
I saw in another thread "GOT THE CAR DONE AT APRIL 3, 2006 11:50PM!!!!!!!!" by 69Rcode_Mach1 that he mentioned he is at 60 PSI and there were some comments mentioning that was high. Ouch... when my engine is cold, I am running closer to 75 PSI, if not a little higher. In addition, when it is hot at ~ 190 degrees, I am still anywhere around 40 PSI at idle. I am using a high volume oil pump... but is this something that is all right, or do I need to address this pressure.

289 with Comp Cams Aluminum Roller Rockers - Comp Cams Hydraulic Lifters - Comp Cams Xtreame Energy cam

Holley 4160 600 CFM - Edelbrock 289 Performer - Hooker Competition headers

Also using Valvoline 10w 30 weight

Thank you for your input,

Scott
Click to expand...


I'm running similar sort of numbers as you (perhaps 5 psi lower) and have been for years. Nothing wrong with those numbers:nice:

Dave
 
#4
Those numbers are great.

According to a few engine blue printing books I've read, a high volume oil pump is a misconcieved overkill kind of part. They were originally designed as a replacement on an older engine with worn bearings to get more life out of the engine before needing a rebuild.

Now I'm not an expert here, just quoting what I've read. These books claimed in the area of 5-7hp savings by keeping a stock blue printed pump as compared to a HV. Unless you are purposely running a "loose" engine with larger bearing clearances for a particular application.

Just throwing out ideas here, I realize it's a common practice to put a HV oil pump on everything.
 
#5
milner351 said:
Those numbers are great.

According to a few engine blue printing books I've read, a high volume oil pump is a misconcieved overkill kind of part. They were originally designed as a replacement on an older engine with worn bearings to get more life out of the engine before needing a rebuild.

Now I'm not an expert here, just quoting what I've read. These books claimed in the area of 5-7hp savings by keeping a stock blue printed pump as compared to a HV. Unless you are purposely running a "loose" engine with larger bearing clearances for a particular application.

Just throwing out ideas here, I realize it's a common practice to put a HV oil pump on everything.
Click to expand...


I've also heard they are unnecessary and I've also heard they can cause problems by pumping too much oil to the top-end and not having enough on the bottom end. But like you, I am no expert and those are things I've heard. I feel very confident that a HV is over-kill in my build and would not use one again for the type of build I have. :ban:

Thanks for the input!

Scott
 
#6
I have read that HV oil pumps can actually be bad for some setups. I was told NOT to use a HV in my 351 build, as the smaller gear could screw up something later..as they have a tendacy to fail..or something like that.

Anyway I am running 45~50 psi on my oil guage when the engine is at normal running temps, and its doing fine.
 
#7
I am running about 35 PSI at idle, 45 at cruise on a stock oil pump. Sometimes when I stop the oil slooshes away from the pickup and goes down to about 15-20, then right back up.


This is on a mechanical Autometer gauge


I have also heard something about too much oil PSI and the bottom end not getting enough lube. I also heard about some oil filters grenading... but I doubt you have to worry about that :)
 
#8
DJCarbine said:
I am running about 35 PSI at idle, 45 at cruise on a stock oil pump. Sometimes when I stop the oil slooshes away from the pickup and goes down to about 15-20, then right back up.


This is on a mechanical Autometer gauge


I have also heard something about too much oil PSI and the bottom end not getting enough lube. I also heard about some oil filters grenading... but I doubt you have to worry about that :)
Click to expand...


is it bad when coming to a stop and the oil goes away from the pickup and then my guage drops to 20 and then goes back to 35???? or does it mean that i need to add oil?:shrug:
 
#9
MustangMatt1966 said:
is it bad when coming to a stop and the oil goes away from the pickup and then my guage drops to 20 and then goes back to 35???? or does it mean that i need to add oil?:shrug:
Click to expand...

When I was almost a quart low, it spiked to zero and then jumped back up on stops, and it also spiked from 20-40 at crusing speeds. On hard stops my pressure still drops when the oil goes away from the pickup, an oil pan with baffles should cure that, but 20psi isn't anything to worry about when its only for a second or so. I tried asking a few people about this, and they said they never really paid attention to the oil pressure gauge when trying to stop... and I can understand why lol
 
#10
DJCarbine said:
When I was almost a quart low, it spiked to zero and then jumped back up on stops, and it also spiked from 20-40 at crusing speeds. On hard stops my pressure still drops when the oil goes away from the pickup, an oil pan with baffles should cure that, but 20psi isn't anything to worry about when its only for a second or so. I tried asking a few people about this, and they said they never really paid attention to the oil pressure gauge when trying to stop... and I can understand why lol
Click to expand...


haha thanks:nice:
 
#12
One thing about high oil pressure is that you are adding to the load on the distributor gear. The distributor gear will wear out more quickly, and metal shavings in the engine are not the best thing to have.

It's also true that a high volume pump can fill up the top of the engine faster than the oil drains back, leaving the sump empty. I wonder how quickly an oil pressure gage reacts to changes in pressure? Could the pressure drop to zero and come back up more quickly than the gage reacts/produces a reading? I would be very hesitant to run an engine where the gage fluctuates as described above.
 
#13
Well ive been running 10 psi at idle for a couple years now, with a max of 50psi at 6500rpm, and its also still holding together. I was concerned at first, but it kinda falls in the 10psi per 1000rpm rule. I'll run it till it blows.
 
#16
My buddies 69 cougar ran more like 7psi at a hot idle for years before we rebuilt the engine, and there was no bearing damage, but there was normal bearing wear, and some scratches inside the oil pump.

I can't recall exactly, but I think there is a ford spec in my old manuals with a min oil pressure of 10psi at hot idle... but my brain may be playing tricks on me.

As for the low oil pressure spike on hard braking, well, that's a bit weird in a pan with a front sump isn't it? That would mean your oil is actually running up the front of the pan and hitting the crank. The opposite happens on a "drag racing start" where Chevy's with rear sumps have an advantage over us.... I think a baffled pan is a must. I like the looks of my milodon. But my engine isn't built yet, so I can't comment on its in use performance.
 
#17
milner351 said:
As for the low oil pressure spike on hard braking, well, that's a bit weird in a pan with a front sump isn't it? That would mean your oil is actually running up the front of the pan and hitting the crank. The opposite happens on a "drag racing start" where Chevy's with rear sumps have an advantage over us.... I think a baffled pan is a must. I like the looks of my milodon. But my engine isn't built yet, so I can't comment on its in use performance.
Click to expand...

Yeah I was wondering how a front sump pan can cause a drop in pressure like that. You'd think it would work the opposite way. It is hard acceleration that sloshes the oil away from the pickup. That is why ford switched to the dual sump pans on the 5.0's.
 
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