Newly built 440 with low oil pressure

[Jon Lowell]

Hello, I have a 440 in my GTX that was just built by a very reputable builder.
It was broken in and runs great.
At cold stat up 70lbs of oil pressure
Took on a 25 min ride on highway at 55 oil pressure is at 30-35 lbs when you come to a stop with car in gear it’s low I attached a pic. When you get on it alittle the pressure will rise to 60lbs. I’m lost. ? In park it’s 20lbs. Any suggestions would be greatly appreciated.

 

[66 Sat]

Seems ok to me, it will depend on your rpm too, if the revs are low at idle in gear then the pressure will be lower.
How accurate is your gauge? Water temp looks pretty high to me too, if the engine's running hot that would thin the oil and decrease pressure.

 

[R413]

All looks great from here.

 

[RemCharger]

To me, both gauges look terrible.

 

[Jon Lowell]

Seems ok to me, it will depend on your rpm too, if the revs are low at idle in gear then the pressure will be lower.
How accurate is your gauge? Water temp looks pretty high to me too, if the engine's running hot that would thin the oil and decrease pressure.

I had just come back from a 40 min ride on the highway so the temp got high when I got home. Shouldn’t temp run 190-210 ?

 

[Jon Lowell]

To me, both gauges look terrible.

I definitely think the idle in gear oil pressure should be at least 35lbs.
The temp may be high due to the fact I just came back from a 40 min ride on highway. It was at 190-195 the whole ride

 

[threewood]

10 psi at idle is normal for my engine. Some guys like more. I'm perfectly fine as long as the oil warning light doesn't come on. Did your builder give you clearances and oil recommendations?

 

[Michael_]

Shouldn’t temp run 190-210 ?

180°F is great, ideally not over 190°F.
But 210°F isn't dangerous in my book. Just not ideal really.

 

[Jerry Hall]

In my opinion if the gauges are correct, fix the temperature problem. On a big block you can change the oil pump without going into the engine. You can change to a higher pressure pump, or just change to 20W50 oil and see what happens. I would like to see that temperature gauge at 190 tops. Multiple things could cause that.

 

[RJRENTON]

Out of curiosity, do you know your bearing clearances?..... for main bearings and rod bearings? Do you know if the re-builder/machine shop installed a HIGH VOLUME or HIGH PRESSURE oil pump? Do you know if any of the lifter bores were machined or sleeved? What type of bearings were installed?
There is controversy wether a high volume pump or high pressure pump is "best". I can only speak for myself and my '70 GTX RS23V0A****** six barrel 4 speed, 4.10 Dana 60. I use a HIGH VOLUME oil pump. My hot oil pressure at cruise RPM is 75 psi; hot oil pressure at idle at ~ 1200 RPM is 50-55 psi at 190°F - 205° F coolant temp. I use 10W-30 Mobil One oil + pint of ZDDP. My bearing clearances: mains @ 0.0025" rods @ 0.0025" with tri metal Clevite 77 bearings (not sure if they're made any longer). Mains are full groove for 360° rod bearing oiling........its been this way for years...I do not race the car....this is what works for me....right or wrong.... Just talking out loud......
BOB RENTON

 

[Nxcoupe]

Hello, I have a 440 in my GTX that was just built by a very reputable builder.
It was broken in and runs great.
At cold stat up 70lbs of oil pressure
Took on a 25 min ride on highway at 55 oil pressure is at 30-35 lbs when you come to a stop with car in gear it’s low I attached a pic. When you get on it alittle the pressure will rise to 60lbs. I’m lost. ? In park it’s 20lbs. Any suggestions would be greatly appreciated.

View attachment 1347662

He's got your bearing clearances at the top end of the spectrum. Lifter bores could be loose as well.

 

[AR67GTX]

I believe 30 - 35 psi at 55 mph is low. Could be the heat. Could be thin oil. Could be large clearances. Could be something else. I don’t know. I like to maintain a 20 psi hot idle pressure which I usually can with 15W-40 oil. But at 55 mph it’s going to be showing at least 55 psi if not higher.

 

[Curiousyellow71]

Sounds like a stock oil pump. Look for a part number on it if there's no record of what you have.

Easy to Install a High volume pump.
There was a interesting engine masters they found no hp loss in going to larger pump.

 

[Fran Blacker]

Are they mechanical gauges or electrical? I prefer mechanical for oil, more accurate. MO

 

[steve340]

Assuming both gauges are accurate.
Oil pressure is a little too low and temperature is too high. Although the original post oil pressure does seem OK when it gets a few RPM going.
10 psi at idle is worn out engine territory. If the engine had done 100,000 miles I would not worry but the engine is apparently fresh.

 

[RemCharger]

Sounds like a stock oil pump. Look for a part number on it if there's no record of what you have.

Easy to Install a High volume pump.
There was a interesting engine masters they found no hp loss in going to larger pump.

Well put.
The pump body can be measured to tell if it's low volume or high volume.

 

[steve340]

I just checked the FSM and it states minimum pump pressure at 500 rpm is 15psi.
Operating pressure at 1000 rpm is 45 -65 psi.

 

[Jon Lowell]

Out of curiosity, do you know your bearing clearances?..... for main bearings and rod bearings? Do you know if the re-builder/machine shop installed a HIGH VOLUME or HIGH PRESSURE oil pump? Do you know if any of the lifter bores were machined or sleeved? What type of bearings were installed?
There is controversy wether a high volume pump or high pressure pump is "best". I can only speak for myself and my '70 GTX RS23V0A****** six barrel 4 speed, 4.10 Dana 60. I use a HIGH VOLUME oil pump. My hot oil pressure at cruise RPM is 75 psi; hot oil pressure at idle at ~ 1200 RPM is 50-55 psi at 190°F - 205° F coolant temp. I use 10W-30 Mobil One oil + pint of ZDDP. My bearing clearances: mains @ 0.0025" rods @ 0.0025" with tri metal Clevite 77 bearings (not sure if they're made any longer). Mains are full groove for 360° rod bearing oiling........its been this way for years...I do not race the car....this is what works for me....right or wrong.... Just talking out loud......
BOB RENTON

Out of curiosity, do you know your bearing clearances?..... for main bearings and rod bearings? Do you know if the re-builder/machine shop installed a HIGH VOLUME or HIGH PRESSURE oil pump? Do you know if any of the lifter bores were machined or sleeved? What type of bearings were installed?
There is controversy wether a high volume pump or high pressure pump is "best". I can only speak for myself and my '70 GTX RS23V0A****** six barrel 4 speed, 4.10 Dana 60. I use a HIGH VOLUME oil pump. My hot oil pressure at cruise RPM is 75 psi; hot oil pressure at idle at ~ 1200 RPM is 50-55 psi at 190°F - 205° F coolant temp. I use 10W-30 Mobil One oil + pint of ZDDP. My bearing clearances: mains @ 0.0025" rods @ 0.0025" with tri metal Clevite 77 bearings (not sure if they're made any longer). Mains are full groove for 360° rod bearing oiling........its been this way for years...I do not race the car....this is what works for me....right or wrong.... Just talking out loud......
BOB RENTON

Not a high volume oil pump. Just a stock melling. I’m definitely going to change oil tomorrow, and I just looked tonight the rear fitting for the aftermarket oil gauge cause is leaking. So maybe that’s effecting the gauge

 

[diesel_lv]

Going to reiterate the bearing clearances, if it was set up loose, it will run a bit low psi. What is your idle rpm? What is 55mph rpm. 10 psi per 1k rpm is ok, depending on clearances. Some are much higher w tighter clearances.
As for temps, too many shadetree mechanics who don't understand a thermostat. A 180 will stay closed to 180 to allow engine to warm up. It will be fully open at 195° and will run once stabilized around 195-210. Mopars in the 60's came factory 180° n 195° t-stats. A 195 will open at 195 n fully open at 210°. If your cooling system is stock, nothing at all wrong w your temps.

 

[Jon Lowell]

Well put.
The pump body can be measured to tell if it's low volume or high volume.

It is a stock pump. I’m going to put a high volume in it. I just seen the rear fitting on the aftermarket gauge on the engine side is leaking. Don’t know if that effect the gauge.