What oil are you guys running in your /6?

[fjr]

I just put filled the engine in my 1965 Barracuda with New Holland 15W-40 (similar to Ambra 15W-40) that I've had for a while. For more pressure, I replaced the stock pressure relief valve spring with a hemi spring. Other than the cam and a 4bbl carb, my engine is stock. Since I'm running about 60 psi at idle and 75-80 psi fully warmed-up above idle with this oil, I'll switch to a 10W-30 Heavy Duty Engine Oil for my next oil change since HDEOs already have plenty of zddp built-in. I'll probably use a PetroCanada Duron-E then.

 

[kyles73dart]

Right now since my slant hasn't run in a while I'm running diesel engine oil in it to clean out the gunk.

 

[Johnny Dart]

Are all of these cars in this thread in stock form ?
How many are hydraulic lifter and harden seat engines ?

In stock form, my /6 solid lift daily driver get's Rotela.

I know why you run Rotella Mike. But so you no the zinc is gone in it.

I run Castrol 10-30 with a little Comp Cams zinc additive in all 3 of my Darts (/6,318,360).

 

[fjr]

I know why you run Rotella Mike. But so you no the zinc is gone in it.

Although Shell has poor data sheets, Rotella still has plenty of zddp (1200 ppm for both 10W-30 Rotella T5 and Rotella T) in it. The latest API service category (API CJ-4) just limits phosphorus (the antiwear component of zddp) to 1200 ppm. Previous 15W-40 grades of API CI-4 oils typically had not more than 1400 ppm of phosphorus. Similarly, Chevron Delo 400 LE 10W-30 contains 1100 ppm of phosphorus.

Adding more zddp to engine oil is not beneficial and can increase the chance of camshaft spalling.