jpatrick62

So I know this topic has probably been beat to death, but I wanted to get some good advice. My 69 L46 convertible has been sitting in the garage since January and hasn't been started because I did a complete front suspension rebuild and installed new SS brake lines, radiator shroud, electrical fixes along with a host of other fixes. So she's ready for July now and I'm going to first change the oil on her 72K mile motor. The motor ran pretty strong before the winter and didn't have any noticeable oil leaks or the such. I was thinking 10W-40 synthetic oil since I run all my cars on synthetic. What oil do you all run in your motors now?

sullyman56

I run Valvoline VR-1 with high zinc. It's not synthetic oil, but the added zinc prevents excessive engine wear on these older engines with the flat tappet cams. Amsoil sells a synthetic oil with a high zinc content.

Tampa Jerry

Check over on the C-2 forum side. Most use Rotella 10-40 diesel oil. The oil is inexpensive and contains the correct amount of zinc for our flat tappet engines. I have been using it for years on my two Vettes and my Chevelle. Jerry

flyeri

Tampa Jerry will probably get flamed for his endorsement of a diesel oil but I agree with him. I ran Rotella 10-30 in my solid lifter/flat tappet engine with absolutely no issues. You can run synthetic oil, or regular non synthetic, but I highly recommend a Zinc additive.

resdoggie

Mobil 15W-50. See specs bottom of page 3.

https://mobiloil.com/~/media/amer/us...pecs-guide.pdf

Douglas Mariani

I use Castrol GTX 20-50 with a bottle of ZDDP in my 1980/350ci & 1968/427ci for decades

Gold Dragon

There was an old saying a while back....People who know, use Valvoline. If you are breaking in a new engine use Delo 400.

pd64

I run Amsoil Z-Rod 10W-30

doorgunner

Do high mileage engines tend to start using oil when going to synthetic oil that is the same wt. as petroleum based oil?

jpatrick62

Yeah, I see the line: "For high HT/HS applications. Racing and Flat tappet applications." Thanks!

jpatrick62

Thanks - I am now aware of the special needs of flat tappet engine designs over modern machines.

jpatrick62

Thanks - I'll look for the Zinc additive or an oil that works with flat tappet designs...

jpatrick62

Thanks Tampa Jerry!

stingr69

Valvoline VR-1 Racing Oil - The Silver bottle version has the additives for conventional oil change intervals and the added zinc for flat tappets.

FWIW - The Silver bottle (conventional base) 10W-30 has more zinc and phosphorous than the full synthetic 10W-30 black bottle version does.

Kacyc3

^ Same but as a 10w30 weight

marshal135

+1 for me Mobil 1 15-50.
Marshal

resdoggie

I think of it this way. Why would I buy 87 octane and put in an octane booster i.e. additive, when I can just buy 93 octane and not bother with an "additive"? KISS principle. But you can see from the responses that ANY brand oil will work in your engine as long as you get sufficient zinc levels.

fastimes

Lucas Oil Hot Rod & Classic High Zinc 10w30 for me.

jackson

FWIW Shell Rotella (aka SOPUS) no longer markets a conventional diesel 10W-40.
No longer markets anything in diesel T3 line. Diesel T4 conventional replaced discontinued conventional T3.
SOPUS markets diesel T4 conventional 15W-40 and 10W-30.
SOPUS markets diesel T1 conventional "straight grade" 10W, 30W, 40W, 50W.

For years I've run Rotella diesel Full-Syn T6 5W-40 in gas passenger/lite truck motors ...
... and diesel T1 30W or T4 15W-40 in diesel MF/Perkins tractor & gas mowers. YMMV

Lotsa regional flat-tappet circletrackers still running Rotella diesel T4 conventional 15W-40. YMMV

? Wonder what type oil new GDCI motors (Gas Direct-Injection Compression-Ignition) will like ?
https://www.sae.org/news/2019/04/hig...hi-gdci-engine

Rescue Rogers

I've been running this since i got my vette and JKippin recommended it. Never a problem.