oil pressure for 427 aluminum block

[COACH MIKE]

I have a stroked 427 (482) side oiler with pond block. I am told the oil pressure will bleed off as the engine gets to running temp (180 h2o temp and 200 oil tmp). I have 100 miles on the engine and when the temp gets to running temp the oil pressure at 1200 rpm is 18 lbs and 35 lbs at 2000 rpm. The oil pressure does increase quickly when rpm's increase.

This is my first aluminum block and is this typical?
Thanks in advance.
Mike

[GRUF78]

After 4000+ miles, mine idles at 25 psi (hot) and 57 PSI at above 1500 RPM.

It goes up instantly if you touch the throttle when hot. 10W40 Rotella oil.

Cold, it is 67 psi at idle.

Pond AL block.

GRUFF

[Bernica]

I have a Shelby 482 here. Runs about 60+ psi on startup, then settles to around 40-50 when warmed up. It eventually goes to around 40+, but does jump and move when I am playing, but always at 40 or more....

[FWB]

Originally Posted by COACH MIKE

I have a stroked 427 (482) side oiler with pond block. I am told the oil pressure will bleed off as the engine gets to running temp (180 h2o temp and 200 oil tmp). I have 100 miles on the engine and when the temp gets to running temp the oil pressure at 1200 rpm is 18 lbs and 35 lbs at 2000 rpm. The oil pressure does increase quickly when rpm's increase.

This is my first aluminum block and is this typical?
Thanks in advance.
Mike

is it typical?......NO

what Bernica experiences is usually typical......it's what i have too.
if it was my new motor, the 18psi would bother me...
what oil are you using? was there a HV oil pump put in it?
does the gauge get erratic?

by just stating the oil pressure of the motor really isn't going to yield a good answer, a lot of factors will determine whether is good, bad, or just OK.

[patrickt]

Originally Posted by COACH MIKE

I have a stroked 427 (482) side oiler with pond block. I am told the oil pressure will bleed off as the engine gets to running temp (180 h2o temp and 200 oil tmp). I have 100 miles on the engine and when the temp gets to running temp the oil pressure at 1200 rpm is 18 lbs and 35 lbs at 2000 rpm. The oil pressure does increase quickly when rpm's increase.

There have been many, many "what should my FE's oil pressure be" threads. Do you normally idle at 1200 RPM? What is the viscosity of the oil that you are running?

[Bernica]

Double-check your gauges, then triple check by pulling a pressure check directly off the motor. If you are still running that low, call your engine builder. Since a kid, I was always taught that 40 lbs was where you want to be. If I'm wrong, this is the place for me to be promptly corrected.

[patrickt]

Bernica -- I'm posting this for historical purposes only because I know you like this stuff. Here are the specs from my 1964 Ford Service Manual. Note that he would barely pass under these original specs. I also have the Owner's Manual that says "disregard the red oil light if it flickers at stop lights" -- which meant you were dancing around 6psi (and I have posted a pic of that on this forum before). All of this is just for reading pleasure, the OP should not rely on it. We really need more facts....

[Bernica]

You are good Sir.
I grew up with the "40psi" rule when running hot. And yes, I was running hard cams....

[mike harter]

Hi oil pressure does not mean better lubrication 40-45 lbs. is fine

[ERA Chas]

The PRIMARY determining factors are what main and rod bearing clearances your builder used. He would have accounted for the expansion of your ally block in the bearing clearances he selected. Call him and ask those clearances and post back here. .002" to .0024" would be good for the mains. Rods maybe .0023" to .0026".
Then oil viscosity and temps. 10 psi per 1000 RPM is an accepted standard. 20 to 25 would be nice for a hot, 1000RPM idle for FE's. But 18 won't melt the motor.
Avoid the problem by no prolonged idle less than 1200 or so.

[Bernica]

Sorry, that was meant for Patrick's message above.

[MOTORHEAD]

Is it a shelby block ? Shelby aluminium blocks are not side oilers so dont go by what is normal for them. Shelby specs:" 80-85 lbs cold @2000 rpm, 60-70 hot @ 2500 rpm" no mention of idle pressure.'

[dcdoug]

Originally Posted by MOTORHEAD

Is it a shelby block ? Shelby aluminium blocks are not side oilers so dont go by what is normal for them. Shelby specs:" 80-85 lbs cold @2000 rpm, 60-70 hot @ 2500 rpm" no mention of idle pressure.'

Except don't most of us with side oilers have ~65lbs oil pressure relief valves?

[patrickt]

Coach Mike, I'm thinking that I remember you saying you had Keith Craft build your engine, but maybe I'm wrong. If it was Keith, then your numbers don't jive with his usual numbers. See this post snap-shotted below for all our beloved slackers: 427 Oil Pressure

[Bernica]

My clearances:

• Main Bearings .0022 ‐ .0025
• Piston‐to‐wall .004
• Rod Bearings .0025 ‐ .0030

Running Joe Gibbs XRP3 oil....

[MOTORHEAD]

Also check it with a mechanical (good quality) gauge at the filter adapter. Your gauge may be faulty.

[ERA Chas]

That doesn't matter-they are all priority main oilers.

[MOTORHEAD]

Chas: I'm just say'in the iron original "side oilers" have a reputation on THIS forum as needing vast quantities of oil @ very high pressures. That may or may not be accurate, but it doesn't necessarily apply to other "427" blocks.

[ERA Chas]

That is true (that they have that reputation) because the current aftermarket block manufacturers use the smaller GM main and rod sizes with much tighter clearances than the original iron blocks used. Using lower viscosity oils is current practice because of that. As 'Cup cars do.
The location of the main gallery feed is not a determining factor.

[Gaz64]

We had the same problem, bad hot oil pressure in one engine years ago.

Any large clearance within the motor will give low hot oil pressure.

In our case, rods and mains were in the middle of spec, BUT cam bearings were too loose.