Engine Oil... Again

[krick3tt]

Not sure about changing to a different grade, but I used to run 30 SAE all the time. I found it was a bit hard starting in the CO winter and there were lots of drips in the oil pan in the garage and the drive after driving. I changed to Castrol 20/50 and although it a bit more expensive, I find that I burn less and there are no drips in the oil pan in the garage, it starts easier (although, that may be from the gear reduction starter). It still takes a bit of work for the engine after sitting for a week or two, but that is from dry carb bowls.
I am content with the 20/50 and probably won't go back to another oil.

[Jimm391730]

From http://www.kewengineering.co.uk/Auto_oi ... lained.htm:
"The viscosity will determine how easily the oil is pumped to the working components, how easily it will pass through the filter, and how quickly it will drain back to the engine. The lower the viscosity the easier all this will happen. That is why cold starts are so critical to an engine because the oil is cold, and so relatively thick.
But, the lower the viscosity, the less the load the oil can support at the bearing on the crankshaft. The higher the viscosity, the better the load it can support. Even this, however, has a trade-off, since the higher the viscosity, the more the drag at the bearing, and hence, potential power loss, or increased fuel consumption. So a compromise is chosen to minimise power loss, but maximise load support. "

Because the Pinz engine is "high torque" compared to most engines, I'm more worried about wear within the engine (I'm trying to minimize the wear by maximizing the load support) so I use as reasonably heavy an oil as makes sense: in SoCal, warm to very warm most of the year, I use 15W40 diesel grade oil as I feel that the diesel oil probably has more of the "bad for the environment" additives that help to prevent wear that are now absent from most automotive oils.

You are probably better off using any reasonable oil weight when you change it regularly, then trying to find the perfect oil (what would that be, anyway?) and neglecting to change it and the filter for a long time. YMMV.

[Mr_Fixit]

Found Valvoline 20W-50 "Race Oil" at my local Napa, on the back it says "high zink formula also protects push-rod and flat tappet engines". I talked to my local BG distributor about his oil and the valvoline and he actually said valvoline was the "next best thing" to his BG oils for thermal stability, evaporation rate and shock resistance.

[ChickenPinz]

Anyone running the Castrol high-mileage variant of the 20W-50? I'm already using that in another vehicle, and am wondering if others have direct experience with this option. My fallback is conventional Castrol 20W-50.

Here's what they tout about it:
- Superior detergency that fights sludge build up
- Exceptional oil burn-off protection exceeding industry standards**
- Seal conditioners to help reduce leaks
- Advanced additives that minimize engine wear

[krick3tt]

I only ever used Pennzoil SAE 30 in my Pinz, winter and summer. Never had an issue. Mine was 1967 710M

[rmel]

The API or "Service category" of Pennzoil SAE 30 is "SN". That designates it as
Catalytic converter friendly -- thus reduced levels of ZDDP anti-wear agent.
Older engines with solid lifters should really use higher levels of anti-wear.

A SEA 30 monograde with higher levels of anti-wear are designated generically
as HDEO (Heavy Duty Engine Oil) Rotella SAE 30 for example, or Mobile HDEO
with a API designation of Cx e.g. CK, CJ, CI, CH. The "C" stands for "compression"
ignition -- Diesel.

Does this really matter -- it all depends. If you trailer your Pinz, not pushed hard
on the HWY, or your not running pushed engine mods, then maybe not. But, if your
pushing your rig hard on long HWY drives and have some engine modes especially the
more aggressive cam for the 2.7L conversion then your pushing your luck. Still, you
may not "see" a difference unless you pull your lifters and inspect for stress induced
pits or cam lob wear. You could also core you oil filter and inspect for metal
particles but if you find particles then the deed is done.

Aviation grade oil is also a good bet for air-cooled engines, it's ashless, better heat
transfer, and proper anti-wear agents but ain't cheap. And then you get to toss a
load every 3,000 miles for proper maintenance.