Oil Pressure/Temp Question

[69'Net]

Oi pressure question: I have a freshly built 440. After the engine is at operating temp, my oil pressure is around 19-21 psi in park idling at 1000 rpms. When in gear, foot on the brake it drops to around 13 psi, 600-650 rpm Is that too low?

Temp question: Also, I have a 180 thermostat in the car. The hottest i can get the car idling is 180 degrees. I'm in Texas, its around 75-80 degrees right now even in February. The temp goes down to about 135 cruising. Is there such a thing as too cool? I even took the fan shroud off. From reading things on here, it seems I have the opposite problem as everyone else.
-Note: I have all mechanical gauges.

 

[1967coronet440]

Oi pressure question: I have a freshly built 440. After the engine is at operating temp, my oil pressure is around 19-21 psi in park idling at 1000 rpms. When in gear, foot on the brake it drops to around 13 psi, 600-650 rpm Is that too low?

Temp question: Also, I have a 180 thermostat in the car. The hottest i can get the car idling is 180 degrees. I'm in Texas, its around 75-80 degrees right now even in February. The temp goes down to about 135 cruising. Is there such a thing as too cool? I even took the fan shroud off. From reading things on here, it seems I have the opposite problem as everyone else.
-Note: I have all mechanical gauges.

When warmed up my oil pressure is around 16psi in gear idling, never had any issues. As far as the temp that is odd it's staying that cool, mine has gotten to 220 in traffic on a hot day, stays around 190 when cruising.

 

[miller]

What weight oil?
Might try a 192-195 thermostat, if for nothing else, to see if the motor runs a little better. BB Mopar motors seem to like a certain temp to run best, usually warmer than 180.
Might want to try another oil pressure gauge, at least to compare readings, to see if what you have is accurate.

 

[lewtot184]

my question would be; are you using a thin modern oil? if your engine won't run hot i'd put an extra $20 in the plate next sunday. 180 is about perfect.

 

[69'Net]

For oil I run 10w40 Brad Penn oil. I've thought about bumping my idle up to around 1100 in park to up the pressure. I will try another gauge as well.

As far as the temp goes, I have had it to 220 and climbing once in traffic with the vac advance plugged. I just hate the way it runs plugged, it idles rougher and runs hotter. Also, I run a cheap 3 core champion radiator with 3 parts distilled water. The engine is bored .060 over. Everyone told me that make it run hotter too. Maybe I need to try a different temp gauge too. Idk

 

[PurpleBeeper]

It sort of sounds like your thermostat is stuck open. I had a 383 that would run at 140 while cruising when I didn't have a thermostat in it. I'd also suggest you bump your idle up just a little bit. The old "rule of thumb" for oil pressure is 10psi/1000rpm, so if your oil pressure goes up when you drive it then you're OK.

 

[mentor70]

did you have your crankshaft machined? and your clearences cked on on the mains?

i would like to see 20 psi or more.

i has heard few guys having problems with the oil pressure bypass valves in the oil pump

 

[69'Net]

I finally got ahold of my engine builder. He said run the idle up a tad, but that was about right for the rule of 10psi per 1000 rpm. The theromstat being stuck open makes a lot of sense. I put a cheap Mr.gasket in there. Maybe I need to buy something a little better quality. Suggestions?

 

[lewtot184]

i messed with some brad penn 10-30wt, very thin. try some rotella straight 30wt and get away from the multi grades. bearing clearances are probably loose.

 

[69'Net]

I run a HFT cam, does rotella have a high enough zinc content?

 

[dvw]

Single weight will do nothing for pressure hot. In my experience bearing clearance makes very ltitle difference in oil pressure. Most pressure loss is thru upper end internal leaks. That being said even 10 psi at idle wouldn't scare me as long as it rises to an acceptable level with rpm. What is that number? For racing to 7100 with good rods that stay round 45 psi was to low, polished the rod bearings. 65 psi worked for over 300 passes with zero wear. This was with 5w30 synthetic.
Doug

 

[Jackpot50]

Put a new thermostat in it, no way 130-40 driving if it is working.

 

[lewtot184]

I run a HFT cam, does rotella have a high enough zinc content?

yep. it's what i use.

 

[lewtot184]

Single weight will do nothing for pressure hot. In my experience bearing clearance makes very ltitle difference in oil pressure. Most pressure loss is thru upper end internal leaks. That being said even 10 psi at idle wouldn't scare me as long as it rises to an acceptable level with rpm. What is that number? For racing to 7100 with good rods that stay round 45 psi was to low, polished the rod bearings. 65 psi worked for over 300 passes with zero wear. This was with 5w30 synthetic.
Doug

my experience has been different.

 

[dvw]

my experience has been different.

Current motor has .003 rod/.004 main. 5w30, 60 psi at 1200. Pressure is nothing but flow capicity vs restriction. Previously bearing clearance was tightened from .004 to .003 did nothing for oil pressure, not 1 psi. Thick oil is just a restriction that slows flow. Its my belief that the only time you need to go to thicker viscosity is for higher oil temp conditions. There needs to be suffecient flow for a given temperature along wth film strength to prevent part contact. If oil pressure is out of limits at a given temperature either there isn't enough pump volume or there is too great an internal leak path.
My 2 cents.
Doug

 

[Dennis H]

On the temperature, mine drops to about 168 when cruising. I too worry about running too cool. Are you using a laser temperature gun to confirm the actual reading? Been using Amsoil Signature Synthetic 10-40 motor oil. It is high zinc, and additive package to massage seals to help reduce leaks. Using it for 10 years big block likes it.

 

[lewtot184]

Current motor has .003 rod/.004 main. 5w30, 60 psi at 1200. Pressure is nothing but flow capicity vs restriction. Previously bearing clearance was tightened from .004 to .003 did nothing for oil pressure, not 1 psi. Thick oil is just a restriction that slows flow. Its my belief that the only time you need to go to thicker viscosity is for higher oil temp conditions. There needs to be suffecient flow for a given temperature along wth film strength to prevent part contact. If oil pressure is out of limits at a given temperature either there isn't enough pump volume or there is too great an internal leak path.
My 2 cents.
Doug

i went from .003-.0035 on the mains and rods to .0023-.0027 on the mains and rods and doubled the hot idle oil pressure (20psi vs 40psi) with thinner oil. loose bearings are a leak. higher viscositys need higher temps to thin out. bleeders will only increase pressure if the pump is driven faster.

 

[Ranger16]

The theromstat being stuck open makes a lot of sense. I put a cheap Mr.gasket in there. Maybe I need to buy something a little better quality. Suggestions?

Stant

 

[dvw]

i went from .003-.0035 on the mains and rods to .0023-.0027 on the mains and rods and doubled the hot idle oil pressure (20psi vs 40psi) with thinner oil. loose bearings are a leak. higher viscositys need higher temps to thin out. bleeders will only increase pressure if the pump is driven faster.

I agree with your statement here. Should have quantified my statement of no increased psi with tighter bearing clearance. The objective was to increase running psi at 7100 in which tightening the clearance did nothing. Increasing idle pressure wasn't something that was a concern.
Doug

 

[AR67GTX]

Don't rod side clearances also have some affect on oil pressure, especially at idle?