Normal oil pressure ?

[428street]

Guys, I have a 428 FE, roughly 10.5:1...it's a mild, streetable build with pump gas...what is a normal oil pressure I should be getting...right now I'm running between 45 and 60 in 5th gear at 2000 RPM...

[mpanten]

There is no "normal" every engine is different but that is well within the safe range.

[428street]

Thanks mpanten...I thought so but I wanted to be sure...I did a 200 mile trip today and it ran flawlessly but I was a bit concerned with the oil pressure...

[mpanten]

Im running 10.5 to 1 in a small block and normal for me is 40psi at normal cruising speed once it reaches it's normal operating temp, even down in the 30's at Idle. Been that way for the three years I have owned it. Dont get to worked up over the oil preassure unless you see a significant drop. There are lots of engines out there and lots of different psi's.

[RICK LAKE]

428street Between 45-60 is a large range at a steady rpm. Is this new oil or old oil? If you are running a HV oil pump in the motor, add 1 quart more than what is called for. The problem is the returns from the heads and block to the oil pan, are slow. A HV pump puts out about 30% more oil than a standard pump. This should also stablize the pressure readings. Do you know if there are limiters in the heads to control oil to the rockers? If not you may want to add a holley jets of .090" to each head. This is for a street motor. For the track an .080" would be fine. Cruising at 2,000 rpms and steady, you want to see a steady reading with maybe a 5 pounds high to low. Any thing more than 10 psi I would be getting another gauge to check out the one in the car. The oil pressure may be fine but the gauge could be off in calibration over time. There is a 10-20 psi differents between the reading you get at the oil filter plate and the heads. As long as you don't hear and rocker noise you are OK. I run a bottle of lucas oil suppliment. I think this helps keep the oil on the parts longer and stops dry startups. You just have to pour it in slow with the motor oil being warm and the engine running. I don't let my motors idle for a long time except when warming up to run. What weight oil are you running? you might want to go 1 range up for the summer months. Rick L.

[mpanten]

Rick,

you have a valid point, if it is fully warm and still fluctuating I would agree. I took to mean that it starts out at 60 then drops when it is warmed up.

[patrickt]

... an oil pressure gauge that fluctuated at a steady RPM. I wouldn't know what to make of it if I did. When I write "fluctuate" I mean the needle is wobbling significantly, or it drops rhythmically, you know -- like a vacuum gauge does with a stuck valve. I can't even think of something that would cause that -- has anybody ever seen that before?

[1985 CCX]

My car runs about 55psi +3

Might be the difference between a mechanical PU and an electrical?

[RICK LAKE]

patrickt A spun bearing in the main trying to weld itself to the crank. At idle it didn't make any noise like you would think.#3 main. The crank just kept spinning. Enough splash from the crank shaft kept it running. This was in a SBC motor. The oil gauge was jumping about 10-15 psi at idle. The rpm was steady. Some motor just don't know when to quit. Rick L

[Argess]

With a high volume pump, small oil pan and cold oil, the pressure can fluctuate after start-up when the car is moved as the oil doesn't drain back very fast. I suppose that could also happen with hot oil if the level is low.

The fix for me was to use a larger capacity pan (Aviad) and switch to synthetic oil after break-in.

With 0.025" bearing clearances and a modified HV pump, I get 85 psi at cold start, 13 to 15 at hot idle and I think about 45 at 2000 rpm when hot.

[ERA Chas]

"With 0.025" bearing clearances..."

How about .0025"?

[Rick Parker]

I once had this going on, turned out to be a crack that had developed in the foot of the oil pickup tube where it was welded to to the strainer. At idle or low speed pressure was normal as the crack was (IMO) totally immersed in oil. When RPM's rose such as steady cruise and oil was being removed from the pan at a faster rate than draining back, the level would drop exposing the crack. Not a good situation, glad I caught it early. That was several years ago, and I have had no negative long term effects.

[Argess]

Originally Posted by ERA Chas

"With 0.025" bearing clearances..."

How about .0025"?

Yup! ....at least my slip up was here, and not in my engine....LOL

[Rick Parker]

13-15 seems pretty low even at idle??

[Argess]

I think it's normal, or at least hope so. And consider, I use a HV pump, I use solid lifters, so I blocked those galleries off, I've enlarged and flared the holes to the oil filter mount, I've restricted the oil to the heads, and I've flared the in the block that feed the crank main journals to match the bearings. And I've put screw-in plugs everywhere there used to be press-in ones. Keep in mind, that once off idle, the pressure rises quickly. I suspect it is just normal for my bearing clearances.

[Rick Parker]

Controlled leakage..........

[Michael C Henry]

What did you do about the front end of top gallery? I remeber a "jiggle pin" back in the late 60s. My machinist just had a small hole in the front plug said it was to evacuate the air on startup and drizzle oil on timing chain. Eight years and pressure is 80 at start up and runs about 50 warm and idle.

[patrickt]

Originally Posted by Michael C Henry

What did you do about the front end of top gallery? I remember a "jiggle pin" back in the late 60s.

Since he wrote:

Originally Posted by Argess

I use solid lifters, so I blocked those galleries off...

then there's nothing at the end of that galley to jiggle or drizzle.

[Michael C Henry]

There should be three galleries running above the cam shaft from front to rear . The top center oil gallery isn't the one you block to eliminate the lifters. I now have a 427 sideoiler. I've had 428s and 406s in the past. They all had those three galleries. The lifter galleries may not even be drilled as most 427 sideoiler were solid lifters. There were some T-birds (the big ones) that had hydraulic liftered 427s. I never saw one in person just read about them. Seems like they were rated at 350 hp. Had to be more than the 390 at 335hp.
With of the increase of usage of hydraulic roller lifters Id bet that some of these old blocks are having those two lower galleries to either side of center gallery being drilled from end to end by machinist today.

[patrickt]

Originally Posted by Michael C Henry

There should be three galleries running above the cam shaft from front to rear . The top center oil gallery isn't the one you block to eliminate the lifters.

Right, I have a 428 that has the side galleys blocked off for my solid lifters and, as I recall, the jiggle pin that was in there for the hydraulic lifters was at the end of one of the side galleys. I looked at my old Ford Service Manuals and they don't even show the damn pin, so I can't be sure -- you may be right on this.