Are My Oil Pressure Readings Normal

[sdcbowler]

Have started my rebuilt 413 engine. It is still in the brake-in stage. When cold, oil pressure is above 50. As the engine heats up, the pressure begins to drop and settles at about 25 psi at idle (Approx. 900 RPMs). I brought the RMPs up to 2,500 and the pressure went back up to above 50 psi. Is this normal, or do I have a problem? The oil in the engine is 10W-40, Sensor and gauge are new. Do I need to go to a different grade/weight oil or use an additive?

Also, how many miles is the 'break-in, stage and what is the maximum spead I should go?

Thanks fellow members

 

[Challenger RTA]

Lube components,Prime engine,Use ZZDP additive. Proper break in on cam 2000 - 2500 for 30 minutes. Check oil filter cut open look for metal. At 2000 rpms oil pressure will be up. Don't let idle to much before break in.

 

[Xcudame]

Oil pressure of 25psi at idle sounds a little low even for 10W-40. The manual lists 45-65psi at 1000rpm. But the pressure going up with rpm is good at least. Of course we don't know your rod and main bearing clearances, etc. Hopefully you've added some zinc additive if it's a flat tapper camshaft. Personally I like to break an engine in with straight SAE 30 and a zinc additive. Usually figure 500 miles of break in before changing oil. Others may have different thoughts.

 

[Chryco Psycho]

IMO you are fine 25 psi at idle is good & it rises with RPM , no problem .

 

[sdcbowler]

Lube components,Prime engine,Use ZZDP additive. Proper break in on cam 2000 - 2500 for 30 minutes. Check oil filter cut open look for metal. At 2000 rpms oil pressure will be up. Don't let idle to much before break in.

Thanks much. Will take this to heart. I did lube the parts and primed the oil pump after assembly.

 

[sdcbowler]

Oil pressure of 25psi at idle sounds a little low even for 10W-40. The manual lists 45-65psi at 1000rpm. But the pressure going up with rpm is good at least. Of course we don't know your rod and main bearing clearances, etc. Hopefully you've added some zinc additive if it's a flat tapper camshaft. Personally I like to break an engine in with straight SAE 30 and a zinc additive. Usually figure 500 miles of break in before changing oil. Others may have different thoughts.

Xcuda,

Thank you for the good advice.

 

[sdcbowler]

IMO you are fine 25 psi at idle is good & it rises with RPM , no problem .

Thanks. I will keep my eye on the pressure.

 

[Steve340]

Don't baby the engine get on the throttle to bed the rings in just avoid flogging the ass off it.
I leave formulated break in oil in the engine for 900 - 1000 miles.
If using full synthetic don't change to it before the engine has done 1000 miles and is fully bedded in.
I did a saloon car engine and we left the break in oil in for 2 race meetings and no problems.

I agree with Chryco - the oil pressure is OK. So long as it builds quickly when you speed the oil pump up I see you being fine.

 

[heminut]

IMO you are fine 25 psi at idle is good & it rises with RPM , no problem .

I agree! I've seen engines that idled at 10 PSI with no problems. Yeah 10 PSI is a little unsettling to see but it's sufficient as long as the pressure goes up when the RPM's do also.

 

[krazykuda]

Have started my rebuilt 413 engine. It is still in the brake-in stage. When cold, oil pressure is above 50. As the engine heats up, the pressure begins to drop and settles at about 25 psi at idle (Approx. 900 RPMs). I brought the RMPs up to 2,500 and the pressure went back up to above 50 psi. Is this normal, or do I have a problem? The oil in the engine is 10W-40, Sensor and gauge are new. Do I need to go to a different grade/weight oil or use an additive?

Also, how many miles is the 'break-in, stage and what is the maximum spead I should go?

Thanks fellow members

I had a similar problem with that on a small block and it turned out that the machine shop left out the oil galley plugs for the lifter bores that are under the camshaft thrust plate...

 

[casper]

IMO you are fine 25 psi at idle is good & it rises with RPM , no problem .

I also believe it is fine as long as you used a stock oil pump. If u put in a high volume pump than it is on the low side

 

[sdcbowler]

I also believe it is fine as long as you used a stock oil pump. If u put in a high volume pump than it is on the low side

I did have a high volume oil pump installed. I figured that could be th problem so I replaced it with a stock pump. Once I start driving it regularly, I will see what happens.
Thanks much.

 

[sdcbowler]

I had a similar problem with that on a small block and it turned out that the machine shop left out the oil galley plugs for the lifter bores that are under the camshaft thrust plate...

View attachment 110817

View attachment 110818

That is so crazy. Good thing you notice it before you assembled, installed, and mounted it to the tranny. I think Mine is ok. I would have seen a mess of oil ont the floor when the engine was on the stand and I was priming the oil pump.

Thanks for the info. Another thing to be mindful of on the next rebuild.

 

[volunteer]

Have started my rebuilt 413 engine. It is still in the brake-in stage. When cold, oil pressure is above 50. As the engine heats up, the pressure begins to drop and settles at about 25 psi at idle (Approx. 900 RPMs). I brought the RMPs up to 2,500 and the pressure went back up to above 50 psi. Is this normal, or do I have a problem? The oil in the engine is 10W-40, Sensor and gauge are new. Do I need to go to a different grade/weight oil or use an additive?

Also, how many miles is the 'break-in, stage and what is the maximum spead I should go?

Thanks fellow members

Your readings are perfect - - IF you have 'fully grooved' mains. Biggest contributor to low oil pressure is bearing clearances.

 

[Adam]

Also, the sender may be out of spec. for your gauge. I recently did a magnum swap (rebuilt engine) in my old Ramcharger. I used the Magnum oil sender but my gauge barely registered. I put my old used sender back on and then my gauge could read it.

Same for the temp sender too. Btw, they look exactly the same. So…. try another sender if you have one.

 

[Challenger RTA]

Adam: I love your truck in you avatar. Always wanted one. You mentioned Ramcharger. So I settled for a 79 in the mid 80's. Sold it because the wife complained about climbing in when wearing a skirt. I said I have no problem with that. She replied: You don't where a skirt. I said I think I would look good in a skirt. She was not amused. One time she said that we were lucky we were in it. As we were crossing an intersection. A driver in a Nova Went around traffic in the left turn lane only. Slammed into the front left tire. Ramchger didn't move. Totaled the Nove Knocked off a lug nut on the Ramcharger. They just don't build stuff like that any more. Sorry about getting off track.

 

[Challenger RTA]

But anyhow back on track. The Ramchager is relevant to this. I would say 99% of people do not understand how to run car's engine. It is ok to start a car and let it run to warm up, because it is at a higher idle. But once warm the idle drops. It is more than likely ok to idle a total half hour. After that I can be destructive. At idle the oil pressure is not there as it should be. I guess the 99% of the driver that let there car idle think it is a diesel truck. Diesel trucks are built different they can idle for long periods of time.
So case and point. The Ramchager I had a problem when I bought it. Not a big problem to me. The salesmen told it was used as a armed security vehicle in the mining industry. (When cleaning it up later I did find a few 357 rounds. I think they were serious.) The problem that was relevant it would smoke a little when first started. So got it took it home changed the valve seals and guides were ok.
That is also true for police cars the idle time is a engine killer.

 

[sdcbowler]

Hey Guys,

(Sorry for the long post, but I figured I would give as much information up front to minimize some of the back-and-forth dialogue)

Still having issues with oil pressure. Have been working with the system so I have a bit more information for you.

Engine: 413 Wedge (Industrial)
Bored .030 over with mild cam…..not lopey
440 original crank


What I did:
Drained oil and removed pan and pickup tube. Did not notice any metal in the pan.
The tube had sludge, so I cleaned it out. The engine has less the 50 actual miles on
The rebuild. Am thinking the sludge was from the assembly lube that never circulated
And mixed with the oil due to the engine not being operated.

I replaced the oil pump and filter. I expected the filter to be full, but it was not. It had
Far less oil than I thought it should have.

Removed intake and valve covers. I tested the oil pump with my mechanical
Gauge and was getting steady Pressure (43 to 47) See video. Was getting plenty of
Oil to the lifters at this time. Once I put the engine back together.

I put the engine back together and started it up (I still have the mechanical pressure gauge connected). The first start of the day (cold), the Pressure is about (See picture titled ‘Cold’). As the vehicle warmed up, the pressure began to drop. The title of the picture equals the number of run time minutes. One thing I notice was that the lifters did not appear to get as much oil with the car running as it did when I was turning the pump with the drill.


Start: Pressure = 40psi @ 700-800rpms

After 1 minute: Pressure = 35psi
After 2 minutes: Pressure = 30psi
After 4 minutes: Pressure = 20psi

Finally, after 10 minutes pressure settled at about 7psi
I turned the engine off

As I increase the RPMs, the pressure would also increase but would never get any
Higher than 20psi @ 2000rpms

As the issue seems to be getting progressively worse, I am considering removing the engine, dis-assemble, re-inspect everything, and then leaving the block for the recycle truck

Any information you all can give would be greatly appreciated

Thanks

 

[Xcudame]

I'm betting you're missing the hidden internal oil plug in the rear of the block. See picture below.

 

[Steve340]

That plug would not cause low oil pressure.
That plug is there to send all the oil from the pump through the oil filter.

It could be another gallery plug, cam bearings or main/big end bearings.