Fresh 427 s/o 40psi oil pressure drop

[Rick Parker]

On my 289 I originally used .0025 clearance for rods and .002 for mains, with oil restrictors throughout. The current Oil Pump is a Precision Pumps (reworked Melling) Hi Volume, High Pressure unit; the newer design with the shaft extending into the bottom cover. This was installed when they became available as I thought the extended shaft was a definate design plus, that had been missing in the Ford pumps. Per Melling the bypass is set at 80#. Using Kendall GT-1 10-40 oil the engine develops 80#+ at cold start up. When warmed up it has a solid 70# at road speed above 2000 RPM and 35#-40# at idle. It has been bullit proof for 14 years. Although it is not a high mileage engine, it routinely get reved above 6800 RPM.

[edwhite7]

I have a Shelby aluminum block and heads. My oil pressure can easily go above 100 lbs cold and I am real careful until the temp comes up. Once the oil gets warm it drops to 55 at 2000 rpm and 20 at idle, the max pressure hot is about 60. I spun the gear off the dist once cause I got carried away before it was warmed up but that was about five years ago. I have a high volume pump with oil restrictors in the head a cast T pan and a Canton windage tray. If I hold above 4000 long enough, well over 100 mph, my pressure will start to bobble. I am convinced that I am pumping the oil up into the motor faster than it can return. The FE heads have a very challenging time trying to drain oil back to the pan and over use of silicon for the end seals can interfere with this. If you pull the dist and the rear breather you can see these drain backs with a mirror. I am always amazed at the number of people who think that a stronger oil pressure relief spring will help low oil pressure. It can make the high higher but the low will be unchanged.

[terry lee]

I had my engine modified to a dry sump system. Something you might want to consider if running high RPM's for extended periods of time. I use to watch my pressure guage bounch all over the place; now it stays pretty steady, except at idle.

RDI in NC made mine for me.

TL

[jimmymac]

ED
Your oil is up in the motor, at higher rpm's. But mainly wrapped around the crank. My oil restrictors are brass screws cut about 5/16's long slotted and drilled with the smallest drill bit ACE hardware carries.062 was too large.Couldn't find it but it was the smallest bit they had. still flows plenty for my Dove rollers. You cant imagine how much oil your engine moves I was shocked when I spun the oil pump with an cordless drill motor. Plastic catch pan under a friend spun it while i watched. It has to move more while running. So keep filters ,coolers fed with an-8 line min. I'll be using an-10 line to reduce friction,and let oil flow unrestricted with a bypass line for the cooler. Your correct let that oil warm up. Excessive oil pressure uses horsepower, More's Law doesn't always apply enough is enough. When my system is full I have almost 12 quarts oil with the oil to the bottom of the windage tray.Knowing that will drop some when the motors fired up. Can you Imigian the turblence all those pistons pumping on the bottom side. a little vaccume on the crankcase doesnt hurt, keeps the seals from leaking,gaskets too. A nice an dry FE what do you know? Thanks All Jimmymac