69 Chevelle 396 big block

[UKCatsfan]

I have a Chevelle with a 396 big block and was looking for opinions on whether I should use dino or syn? I put about 1000 miles a year on it and is garaged in the winter months. What is the consensus of the following? Thanks

GC
Mobil 1 10w30
Havoline 10w40
redline 10w40

 

[Rob Taggs]

With the old style seals in that motor you might be better served with conventional oil. Also, depends on the condition of your engine. I know motorheads with these old blocks that run synthetic with no problems. I had a 396 bored out to a 402 in a 1978 Chevy Blazer. I romped on the throttle real hard one night, the next day I went out and started the truck up. Well, it was smoking like a factory chimney. Didn't see the smoke prior because I was running it hard in the middle of night. I was running Castrol GTX 20w-50 motor oil in it. Buddy torn down motor and found that I had burned 5 intake valves out!

 

[Al]

I would stay away from Mobil 1, GC, RedLine bc of the PAO (Synthetic) and the RedLine (Ester Synthetic). I probably would go with Any of the New GF-4 oils.

 

[sbc350gearhead]

I am guessing this is a fair weather only car? A 15w40 HDEO might fit the ticket. I would want to see a couple of UOA's of the new GF-4/SM stuff in an older engine with a flat tappet cam, before I could recommend them.......JMO.

 

[Al]

quote:

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Originally posted by sbc350gearhead:
I am guessing this is a fair weather only car? A 15w40 HDEO might fit the ticket. I would want to see a couple of UOA's of the new GF-4/SM stuff in an older engine with a flat tappet cam, before I could recommend them.......JMO.

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You are probably right.

 

[Gene K]

Valvoline VR-1 20W-50 if it is a Mechanical Cam. A proven Combo.

If it is a Hydraulic Cam I would not go over 15W-40.
For that application I would suggest Mobil 1 Truck and SUV 5W-40. Or for a lower cost alternative Shell Rotella T Synthetic 5W-40.

Gene

[ December 12, 2004, 10:40 PM: Message edited by: Gene K ]

 

[ebaker]

M1 15w50. Add 1/2 a bottle of GM EOS if your valve springs are heavier than stock.

 

[Dart-Swinger]

I've been using Mobil-1 15w50 in my modified 1969 340 Dart for three years now and it is great.I previously used Castrol syntec in 5w50 and this is a great improvement over it.It starts better and holds oil pressure better too.And I noticed that the lifters stay pumped up alot longer

 

[Hirev]

My vote would be for a very good additive package dino oil such as found in 15w 40 HDEOs. Chevron Delo 400 and Mobil 1300 come to mind. I always had good luck with HDEOs in my BB powered cars. I always like the 396s Chevelles.

 

[FFeng7]

Whats wrong with running a thicker oil then 15w40 in an engine with a hydraulic cam?

 

[Pat in Speedway]

My brother has a '72 Chevelle SS with a 454 bored out to (I think) a 502 w/nitrous.

He swears by M1 5w30, which to me is too thin for that application. But hey, it's worked for him for years though.

 

[novadude]

My Dad has a '70 ss396 Convertible. We built a '69 396 for it, as the origial engine was missing. We were using Valvoline VR-1 20W-50, until I found this site, and started to learn that 20W-50 may be a bit thick for that engine.

Lately, he has been using Havoline, or Pennzoil 10W-40. He drives the car about 1000 miles per year (summer months) and does an annual oil change in the spring. This is a mild hydraulic cam engine, and the car is primarily a cruiser.

Big Block Chevys are somewhat hard on cams, since they have a heavy valvetrain, high ratio rockers, and often run spring pressures that are a bit high. I would think a 15W-40 HD oil would work great in this application. So far, the passenger car 10W-40 oils are doing a good job in this 396. We have not used any GF-4 oils yet.

Out of the oils listed, Havoline 10W-40 gets my vote. No need for synthetics... just use a quality dino, and change it at the start of the "cruise season". If you want xtra protection, run a 15W-40 HD oil.

 

[k1xv]

If it has the original seals, I would avoid synthetic, and run something like Mobil Delvac 1300 15w-40