What weight oil are you running

[SGBARRACUDA]

10-30 Lucas Hot Rod in my hydraulic lifter 360 and my solid roller 416.

 

[Nat]

I ran ROYAL PURPLE 10-40 synthetic on my 340 for 7 years and 20,000 miles when i removed it everything looked new inside . i used zinc additive for the first few oil changes after that I'd add a little zinc every 2 or 3 oil changes . on my stroked 360 a musing valvoline vr1 10-30 synthetic for now . as long as you use a good oil and change it often enough you should be good , and i have never used a quart between oil changes every 5000 miles

 

[Wyrmrider]

https://www.widman.biz/uploads/Corvair_oil.pdf

 

[rumblefish360]

Great read Wyrm.

Used it on my last summer road trip to the USA in my '72 318 SSP (rebuilt in 1979).

View attachment 1715534089

I have never seen such a super heavy thick oil like that ever before. Wow!

Mattax’s list below about sums it up. Based on bearing clearances, I’m running a 10/30 or 5/30. I have fresh rebuilt engines and the “10” is more than enough, the “5” is what I’d rather have in the crank case, but nothing lighter or heavier if I can. The “30” is right for my engine. The clearances are on in the middle to tight side of the listing.

This ^^^^^^^^

Here's what was posted in:
Oil Viscosity vs Bearing Clearance
and discussed in posts here
Valvoline VR-1 vs. Lucas Hot Rod oil
Your engine builder may have some thoughts on this too.
For street & strip use the following SAE grades:
Rod bearings with
.0015 to .0018 use 20
.002 to .0024 use 30
.0025 to .0029 use 40
.0030 to .004 use 50

For main bearings:
.0015 to .002 use 20
.002 to .0025 use 30
.0026 to .003 use 40
.0031 to .0041 use 50

For general use, its usually better to use a multi-grade.
whateverW Same will provide better lubrication when the oil is not fully warmed up than a straight grade.

Some recommended rod bearing oil clearances for various oil viscosities:
.0015 to .0018 for 0W20 or 5W-20
.0020 to .0024 for 5W-30 or 10W30
.0025 to .0029 for 10W-40 or 15W40
.0030 to .0040 for 15W-50 or 20W-50

For main bearings:
.0015 to .0020 for 0W20 or 5W20
.0020 to .0025 for 5W-30 or 10W30
.0026 to .0030 for 10W-40 or 15W40
.0031 to .0041 for 15W-50 or 20W-50

After break-in, depending on how it was machined, probably best to use a conventional base stock for a few thousand miles.
One current option for a conventional with decent Zddp levels is "Ford Super Heavyduty" meets FORD WSS-M2C171-F1
PETROLEUM QUALITY INSTITUTE OF AMERICA TEST PROGRAM

 

[TrailBeast]

Nobody is using Mobil 1 or some of the other full synthetics?

I run 5-30 Castrol Syntec full synthetic, but I have a Magnum roller motor so it doesn't really apply to this thread.

 

[Mattax]

I run 5-30 Castrol Syntec full synthetic, but I have a Magnum roller motor so it doesn't really apply to this thread.

But you answered the question in the title.