What weight oil are you guys running in the big Hemi's and Wedges?

Valvoline VR10X30Wt
Works good, last a long time in my motors with vacuum pumps

Driven GP-1 synthetic blend 15-40. Very clingy oil.

15-40 delo 400. Change it often.

Rotella 15-40.... 540" wedge.

Depends on the clearances used when building the motor. Typically bigger clearances need heavier oil.

Exactly. Most new cars are running thin synthetics, but their bearing clearances are tighter. As an example, if your clearances are say .0025" on the mains and .002" on the rods, that's a little looser than most engines came from the factory, and you're okay running a medium weight oil, like 10w-30 or just 30w if you want something a little thicker. If you're engine was built loose like some racier engines are, say .003"-.0035" on the mains and .0025" on the rods, I would think you may want to run a heavier oil.

I also like the idea of running an oil with zinc, even on a roller cam motor that may not require it.

Penn Grade 20/50 in my 505 wedge . If you are sitting peak hour traffic for extended periods or extended highway use heavier oil may be a good thing . I do run a solid flat tappet cam . JMO .

Tex

VR1 20/50 mostly but I have used the 10/30 also. Its just not as accessible as the 20/50.

Weight will be determined by how much it's internally hemorrhaging (bearing clearance, lifter bore clearance, oil leakage through pushrods, etc) and oil temp. My new motor isn't particularly "oil efficient" plus with the block being filled the oil temps are on the high side.

So for me I had to put 20w-50 in it to get the oil pressure up where I liked it.

My piston to wall clearance on this one is tighter than previous, but most are about .003" for clearances. I typically run Brad Penn 20-50 and was wondering if I should switch to straight 50w? I burned #7 bearing last year again, so I do not want to do that again.

I would think you'd want to run (ideally) the thinest oil that will get you the pressure you need.

Idea here being:

1) any system leaks will bleed the pressure
2) thinner oil will make that bleed easier to happen: the thinner it is the easier it will be for it to escapte through any such path
3) of course you need volume to carry the heat away, so pressure isn't the only metric to watch, but as far as leaks go it's a darn good indicator

My stroker motor has:
1) 0.032 - 0.035" clearance on the MAINS
2) 0.020 - 0.023" clearnace on the RODS

I intend to run VR1 10W30, but if that nets me an uncomfortably low pressure I'll move up to 10W40, or 15W40.

Right now the crankcase is full of break-in oil (30), only 1 startup so far, but it was a steady 45-50 at idle and 75 at the initial start and about 2K RPM.

I found this DRIVEN reference chart to be pretty handy, take a look at the attachment.

540 street/strip Hemi, and 499" street/strip wedge. Used to run 20-50, then tried the 15-40, and then tried the 10-30.

Valvoline VR-1 10-30 is what has been in both engines the last few years. No synthetic, no additives. Both engines have SFT cams. Good hot pressure and no problems.

I use 20w50 VR1 and have used Brad Penn in the past.

I primarily use that weight it because we use nitrous and try to absorb the shock a little better.

I pulled it apart a couple of winters ago and was surprised at how well the bearings and the main caps looked! Almost no fretting on the caps and the bearings had virtually no wear.

This is all on a stock block with studs and spraying 250 shot.

I use 15W50 but also try to make sure the engine has some oil temperature in it before making passes. Thinner oils are better if you don't spend any time warming it up at the track for sure. The thicker and/or straight weight oils don't flow as well cold. In some other applications we've failed engines with heavier weights at cold ambient temps because while it has pressure, the oil isn't flowing to all of the appropriate bearing surfaces.

Yep, even after a brief warmup down the return road, the car will usually gain quite a bit due to all the oils and lube being warmed up after a pass.

On the oil pressure with warm, above 160 F or hot oil I like to see 10 Lbs. per thousand RPM, if it shifts at 6500 RPM I like to see 65+ Lbs. at that RPM.
I do trim or add spacers to the bypass spring as needed to achieve that, my old pump gas 400 stroker motor would idle at 850 RPM in gear and have from 18 to 22 Lbs oil pressure 60 lbs at 1500 RPM with 180F+ oil temps when revved up above that and gain another 5 lbs. above 3000 RPM

Driven XP3 in everything for me. Street car and racecars, all aluminum blocks.

I try to run as thin as possible. Thin enough to have 15-20psi at hot idle but also not have 100PSI through the traps once the oil cools off from the drive. My car is faster the cooler I can run it so I try to keep the engine as cool as possible. I normally try to hit the burnout box at 140 coolant temp, it slows down .1 if I hit the box at 160. Stupid naturally aspirated racing lol.

Castrol GTX Conventional 20W-50 in a 512".