I finally got around to installing an oil psi gauge, and it is always about 45 to 50 psi. Hot, cold, idle, 3000 rpm. It never changes. It might drop 5 psi when its hot and at idle. Thinking my new electric gauge was bad, I swapped the electric gauge for a mech gauge, no change. What happened to the 10 psi per 1000 rpm rule?

I have been looking back at multiple threads re: oil, oil psi, cam gear, oil pump drive gear failure, etc. All of my vehicles are older, and I normally run Delo 400 15W40, with a NAPA filter, and I have never had a problem. My /6 is 120K all original 1970 never been out of the car. Ambient temps are usually above 75 F anytime I am driving the car,We don't get snow or freezing stuff here.

This oil psi appears normal for some guys/ cars, not normal for others. Is this a characteristic of the NAPA 1806, or a characteristic of the oil viscosity? There was a recent thread about oil viscosity where several members commented on their oil psi.

I guess it is not a problem, it's not a bypass stuck open, bad psi regulator, etc. I can't think of a mechanicsl problem that would cause high oil psi at idle, but nomal otherwise. I am just trying to make sense out of the readings. Does anyone think this is a problem?

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NO WHINING and NO EXCUSES!

Usually the 10 psi rule is if you are going over normal cruise speeds....


My current mill with a standard Melling pump (not the HV pump)...spits out 50-60 psi up to about 4000 rpm...then increases to 75 psi....

I noticed with all the hot weather we are having when the 10W30 gets warm the PSI goes from 50 at idle after 20 minutes on the freeway
to about 75 psi at idle when warmed up...

I need to loosen those clearances a bit I think...

-D.Idiot

On cold startup I get about 40-50 psi at idle. After its warm I get about 20 psi. At highway speeds I get between 38 and 52.

Don't think I've ever gone above 55 psi and certainly not up to 75. I do use 10w-30 Mobile 1.

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'66 Dodge Dart

I noticed a similar issue with my car lately too. At idle I'm right around 50psi, but when I was at higher RPM (not even that high mind you, basically as soon as I hit the gas) and at cruising speeds it was around 100psi. Made me very nervous to say the least, as the last time I drove it I was around 70-80psi at higher RPM and cruising speeds, which still seems a tad high.

Any cause for concern here? I checked the oil level and it's still full, no excessive blowby, leaks, etc... or anything of that sort. Anything I should be checking as the route to this issue?

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1963 Plymouth Fury 4-door, 225 /6, 3-speed manual w/ OD, "super six", Mopar electronic ignition

Fury, what kind of oil are you using? Higher pressure is caused by more resistance, which is the result of thicker oil, smaller passage ways, or higher volume oil pump. So it could be that you use thicker oil, or if you've recently switched to a synthetic it could have knocked loose some old mineral based oil buildup which is now clogging an oil passages.

Does anybody have a spec for normal psi for these engines? The FSM recommends the use of SAE 30 oil (I believe in various multi-grade favors, straight SAE 30, 10w-30, and possibly 5w-30?), but I didn't see a oil pressure specification. Is less pressure (20-50psi) better, or is higher pressure (45-80psi)? Or does it not matter as long as you are above 10-15psi?

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'66 Dodge Dart

Are these readings using a mechanical oil gauge?
If so, it sounds like you have a sticky regulator valve in the oil pump.
If it is an electric gauge, the gauge sending unit may be off.

Search on cleaning procedures. Doc has some good pictures of how to do it.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

The '79 manual says:
Minimum pressure at idle: 8 psi
Operating pressure at 2000 engine rpm: 30-70 psi
Pressure drop from clogged filter: 7 to 9 psi

Olaf

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Aspenized

I am using a full synthetic 10w30 Mobil 1, so the point about breaking material loose makes sense, I'll have to dig a bit further...I have no idea what oil was in the car prior to my changing it. The car didn't run funny or act weird at all, just the pressure was high. The gauge is an electronic gauge mounted to the dash along with an engine temp gauge.

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1963 Plymouth Fury 4-door, 225 /6, 3-speed manual w/ OD, "super six", Mopar electronic ignition

Thanks! And what section did you find that in?

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'66 Dodge Dart

Specifications Six Cylinder Engines 225 in section 9, page 53, heading: ENGINE LUBRICATION

Olaf.

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Aspenized

My roadster with a factory oil pump runs about 55lbs at road speed and drops to 20-25lbs at hot idle.

My Valiant in which I just put a high volume pump in, runs about 40lbs at hot idle and 55-60lbs at road speed.

Both have good mechanical gauges and have been doubled checked with a second known working gauge. I also run Valvoline 10/30 conventional motor oil.

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