Correct oil pressure for 454?

[ClydesdaleKevin]

Hey guys,

Now that my gauges are all reading correctly, or at least steadily and consistently, after fixing all my wiring and grounds, my oil pressure gauge now reads just slightly higher than 70psi at 2700 RPM, whereas before,when all the gauges were reading lower, it read right around 60psi.

What is the normal operating range for oil pressure on a Chevy big block 454?
I want to make sure it isn't running too high.

I think I read somewhere that 40-80 was the correct operating range, but want to make sure.

Thanks!

Kev

[DaveVA78Chieftain]

My 1992 P30 manual says for a 454:
10 psi minimum @ 500 RPM
40-60 PSI @ 2000 RPM

For reference, The 73-77 Dodge manual says for a 440-3:
8 psi minimum @ idle
30-80 PSI @ 2000 RPM

Yous sounds like it is in the expected range.

Dave

[ClydesdaleKevin]

Thanks Dave!  I'm getting 40psi at idle (700 rpm), and just over 70 psi at 2700 rpm, so it looks like I'm right within specs.


Kev

[Bigjohnk99]

My 1983 454 seems to run about 30 psi no matter what the engine speed is.  Is this too low?

[ClydesdaleKevin]

Seems lower than it should be, but don't get too worried...the stock gauges on these things suck, especially if you have any ground issues.  Check the back of your gauges where a bunch of ground wires come together on the gauge mounting nuts and make sure they are all tight...they loosen up from road vibrations.  I'm going to be installing a mechanical oil pressure gauge in the near future to take the guess work out of it, as well as a mechanical temp gauge and vacuum gauge.


VERY sexy rig by the way!  I'm a little partial to the Holiday Rambler...lol!  Outstanding engineering, and they have the Muscle Car look of the vintage RV world.


Kev

[HandyDan]

BigJohnK99, Out of curiosity, does your Holiday Rambler have an oil pressure cutoff switch for an after market electric fuel pump? This shouldn't affect the oil pressure gauge unless it was installed wrong or the sender unit was bad. 

[Jerry]

I just bought a 83 HR Imperial with the 454 paper work shows new long block 500 miles ago along with new oil and temp gauges. My problem is this thing runs at 20 psi oil going down the road and 220 degrees temp, both numbers seem wrong to me but some say it is ok even the shop that done the engine work says temp should run 220-230. Has anyone saw oil pressure this low and it be normal? The temp is not a cooling problem it is a high temp thermostat all the cooling system is new!

[MotorPro]

Too hot and too low on pressure. A 454 should have at least 30 at idle and 45 going down the road.

[beaverman]

Temp should be around 185, pressure as stated in the last post unless it's running a hi volume oil pump, mine has a Melling hi volume and runs at 45 at idle 60 at cruise

[HamRad Mobile]

Good morning; 

     One other thing I have learned about oil temperatures: 

     The most or highest that I have seen recommended for automotive application engine oil is about 240 degrees Fahrenheit.  That is the same recommendation that I have seen for piston engines for aircraft.  At that point, the oil and its additives begin to lose their effectiveness.  Keep it under 240 degrees, and I start to get concerned if it is up in the 230 degree range. 

     In our application, an external oil cooler with a thermostatically controlled fan may be useful when climbing grades on a hot summer day.   The most that the oil temperature gauge installed on my Chevrolet 454 engine has ever displayed to me was about 215 degrees when climbing up Snoqualmie Pass.  My real test later this summer will be climbing the grade on Eastbound I-84 East of Pendleton, Oregon.   

          Enjoy; 

          Ralph 
          Latte Land, Washington 

[Jerry]

Thanks It already has a twin elec fan and oil cooler new radiator, and water pump so it is not the system I think I will change the thermostat so it doesn't get so hot!

[Rickf1985]

Just do not go below  180 thermostat. If that is what you have or even if you have a 195, if it is running in the 240 range then the thermostat is already wide open unless it is bad or clogged. A 180 is a good choice for a motorhome. But if you are still running hot after that you will need to find out why.

[tmsnyder]

What weight oil are you running? 


I think 195 is the standard thermostat on these. 



Is this on a P-30 chassis?   I think those twin electric fans are triggered only from running the A/C.  The schematic for that is on page 32 of the chassis manual I found here:  http://www.gmcmi.com/wp-content/uploads/2014/05/P30-Chassis-Manual.pdf

Looks like the radiator has to be hot, and the A/C running for the twin fans to turn on.  I haven't gotten to looking at my A/C yet so I can't verify this.  So you'll only get the benefit of those fans when you're running the A/C, which puts a larger heat load on the engine. The fans might offset that, but who knows?  If it was me and the engine were running hot I'd shut off the A/C.

Thanks It already has a twin elec fan and oil cooler new radiator, and water pump so it is not the system I think I will change the thermostat so it doesn't get so hot!

[Rickf1985]

If you are running the stock radiator there is a sensor in the top left that turns the fans on at a set temp, probably 195 degrees. This sensor is tied into and uses the relay for the A/C to power the fans. Pink wire if I remember correctly. Don't quote me on the color, I just seem to remember that for some reason when working on mine which was a wiring nightmare.

[tarifachris]

From the P30 manual...

OPERATING TEMPERATURES

Engine Oil - Page 7-8 Normal engine oil temperature in between
coolant temperature and 50 degrees above.

Coolant Temperature - Oil pressure 30 to 40 PSI while driving under operating
temperature and moderate road speed .

Engine Coolant - Minimal operating temperature 200. Redline is 240° with
195° thermostat.

With my Holiday Rambler at cold start I have 50 PSI oil pressure and 35-40 on the road and at idle. Mobile 1 5W-40.

In Phoenix at summer (105 degree) my coolant temperature is 210 to 220. At 220 the fan clutch engages into full speed
and after 20 seconds it is down to 210-215. On my last trip from Arizona to Oregon on long hills it goes to 230 even with engaged
fan clutch. My transmission temp is normal at 180 and at hills 200 / Dexron IV transmission fluid.

Just passed emission test easily - engine is in great tune up.

P.S. I run two additional transmission coolers with a manual switch for the fans

[Jerry]

The old girl is getting new gauges, yesterday I used a inferred temp gauge and discovered I do not have a over heating issue it's a gauge/sending unit issue. Since I hate electronic gauges anyhow she is getting new manual temp and oil gauges I hope the low oil pressure is also just a faulty reading. I new something was off on the temp since it never seemed hot no boiling over or smelling hot! Hopefully this will be the last of engine issues for awhile and I can get back to killing gremlins in the coach!