Oil Change

[cycleguy55]

Interesting read here, albeit very long. The net of this is that he basically dismisses as myth the requirement for ZDDP (a.k.a. zinc) that many strongly believe in for flat tappet / lifter engines, and recommends certain types of high quality 5W30 synthetic pretty much universally.

https://540ratblog.wordpress.com/

The weight / viscosity of your oil s/b based upon the clearances in the engine, as indicated by pressures you're seeing. Standard guidance for many has been 10 PSI per 1,000 RPM at operating temperature, so 60 PSI @ 6,000 RPM. Running heavier / thicker oil than that not only requires more power to pump, but may also result in insufficient lubrication to tight clearances - particularly when cold (yes, even with multi-viscosity oils).

[ACHiPo]

Originally Posted by cycleguy55

Interesting read here, albeit very long. The net of this is that he basically dismisses as myth the requirement for ZDDP (a.k.a. zinc) that many strongly believe in for flat tappet / lifter engines, and recommends certain types of high quality 5W30 synthetic pretty much universally.

https://540ratblog.wordpress.com/

The weight / viscosity of your oil s/b based upon the clearances in the engine, as indicated by pressures you're seeing. Standard guidance for many has been 10 PSI per 1,000 RPM at operating temperature, so 60 PSI @ 6,000 RPM. Running heavier / thicker oil than that not only requires more power to pump, but may also result in insufficient lubrication to tight clearances - particularly when cold (yes, even with multi-viscosity oils).

A guy in our club is a retired oil engineer from one of the big US refineries. A good part of his career was spent developing and providing oil for race cars, sponsored and unsponsored. When I showed him the 540Ratblog (after being pretty impressed myself), he ripped the methodology to shreds. The author is making a lot of unfounded statements that he backs up with pseudo science and testing.

The recommended oil from the guy with experience? Delo diesel when it used to have 1200ppm zinc, now Delo diesel with ZDDP additive. Based on that I'm running Rotella 15W40 as it still has 1200 ppm ZDDP in my flat hydraulic tappet motor.

[sea2jet]

10 psi at idle seems very low.

Originally Posted by cycleguy55

The weight / viscosity of your oil s/b based upon the clearances in the engine, as indicated by pressures you're seeing. Standard guidance for many has been 10 PSI per 1,000 RPM at operating temperature, so 60 PSI @ 6,000 RPM. Running heavier / thicker oil than that not only requires more power to pump, but may also result in insufficient lubrication to tight clearances - particularly when cold (yes, even with multi-viscosity oils).

[patrickt]

Originally Posted by sea2jet

10 psi at idle seems very low.

Actually, it's not -- depending on what your idle is, of course. Let's say you're idling down at 700 RPM with a hot idle at 10 psi in a brand spankin' new stroker FE, say a SCAT with the Chevy journals, and clearances approaching .003", and a nice HV oil pump. 10psi is nothing to even blink at, provided the pressure comes up right off idle. The original 427FE didn't even flicker the light until 6psi - and the service bulletin's recommendation for when that happened was to just raise the customer's idle a bit. The need for a higher psi at hot idle is all in your head.

[ERA 626]

Originally Posted by patrickt

Actually, it's not -- depending on what your idle is, of course. Let's say you're idling down at 700 RPM with a hot idle at 10 psi in a brand spankin' new stroker FE, say a SCAT with the Chevy journals, and clearances approaching .003", and a nice HV oil pump. 10psi is nothing to even blink at, provided the pressure comes up right off idle. The original 427FE didn't even flicker the light until 6psi - and the service bulletin's recommendation for when that happened was to just raise the customer's idle a bit. The need for a higher psi at hot idle is all in your head.

I have to agree with Patric here, My FE in my ERA car (454) ran at 10psi all day long at hot idle, as soon as I touched the peddle it jumped up...it has been this way for may years, no issues

[spdbrake]

This Melling article is a good read and help diagnose if you think you have a problem or not.

https://www.melling.com/aftermarket-...u-k/technical/

[patrickt]

And speaking of Chevrolet, what do you think the installation guide from Chevrolet lists as the minimum oil pressure at idle (1000 RPM) for a nice, new 454 HO crate engine? Answer: 6 psi.

https://www.chevrolet.com/content/da...e-12568774.pdf

[cycleguy55]

Originally Posted by patrickt

And speaking of Chevrolet, what do you think the installation guide from Chevrolet lists as the minimum oil pressure at idle (1000 RPM) for a nice, new 454 HO crate engine? Answer: 6 psi.

https://www.chevrolet.com/content/da...e-12568774.pdf

I also note the recommendation for 5W30 non-synthetic. No mention of ZDDP as that's a roller cam engine.