MY 2 cents worth of opinion:

I have run 15W-40 motor oil intended for diesel engine use in both of my FE 390-powered Slicks, in my 2.3L Ranger and in my 2.5L Jeep (snowplowing) for many years without any concerns or problems.

My reasoning being based on the information that I've read indicates the diesel motor oils have a tendency to contain higher amounts of Zinc (Zn) than most standard motor oils. I can typically locate it at the local Tractors Supply Co (TSC) store in 2-gallon jugs and it is competitively-priced.

By the way, both Ford FEs, the Ford 2.3L DOHC and the AMC 2.5L all get & use the same oil filter; the Motorcraft FL-1A.

Lastly, they all get a quart of LUCAS HD Oil Additive at each oil changing.... 'cause they like it!

-- It works for me!
BarnieTrk

 

I have read this article before... My Father and my Uncle were both Chemical engineers for oil companies...My Father died a few years ago after almost 60 years in the oil industry. My Uncle found the validity of the article as dubious. He carries a Chemical engineering Degree from Yale, and has worked for Atlantic Richfield aka ARCO since back in the late 1940's...and more recently was the VP of engineering for Stauffer Chemical an additive manufacturers.. He holds a great many Patents, mostly in Aircraft fuels, and I have a tendency to trust his Active knowledge over a website chat posting in which the author's name is different in a few different places... There are a great many valid points in the article.. but I have to go with the Men with the degrees, and the really big homes....

 

As some on who has wiped cams on break in, i will never ever forget to use the zinc. I use diesel rotella for break in.

The zinc is no longer in the oil due to tighter tolerances and most manufacturers of gasoline duty engines have switched to over head cams with followers or roller cams that do not have the pressures or rotational wear inherent in a flat tappet mechanical or hydraulic type lifter.

Garbz

 

So true.. On Aircraft Engines we use 40 weight Castor oil with a zinc additive for the first 40 hours, then do an oil change and the same mixture until 100 hours, then another oil change to straight 40 weight, with the Zinc additive, and then oil change every 100 hours there after.... It is all about Cam, and lifter wear, and break in. You want to temper the cam shaft properly to prevent cam shaft failure. Too much heat to fast can cause the Cam shaft to become brittle and prone to breaking... The heating and cooling cycles when new causes the metal to temper...Both Edelbrock, and Comp Cams explain it very well on their websites, and both require that you use break in additive for at least the first 5000 miles of a new cam. They also both suggest that you run the engine at 3000 rpm for 20 minutes on first start up to help with the tempering process... if you have all roller cam/lifter/rockers go for the Synthetic, after break in... but other then that why spend the bucks if there is no real benefit.

I tried the 15W-40 in my FE but found that the oil pressure would be almost alarmingly high until the engine was fully warmed up idling at close to 70 PSI, and then it dropped into a normal range .. SO I will stick with the 10W-30 all is right where it is supposed to be, and 10W-30 is not hard on the wallet either... The 10W-30 Idles at 45PSI until warm and then it sets at 32-35 PSI at Idle.. Excess oil pressure can be as bad as very low oil pressure, as it can cause gasket failure in some cases... ahh it is all a matter of what you are comfortable with..


Cheers all

 

JCP,

I'd much rather have high oil pressure than low oil pressure!

Yep, my oil pressure gauge reads >70psi when I fire up my 390, (especially when the outside temps are < 50*F) then it calms down to 35-45psi when the engine is up to operating temperature; suffice it to say say I am comfortable running higher than 'normal' oil pressure pressures. Of course I don't rev the engine excessively or put it under a strain until it has reached normal (160*F) operating temperatures.

High oil pressure will not blow a seal if your PVC system / blowby tube is working correctly. The only downfall to excessive oil pressure I can envision would be a loss of a few HP due to working the oil pump more than is necessary when spinning it at the higher end of the rpm scale, probably not an issue unless you're in a racing situation.

Maybe your gauge is faulty?

BarnieTrk