Crankcase Oil

[Don C.]

I just purchased a '56 Corvette with dual quads. What is the recommended engine oil for this car. I would appreciate specific brand and type info.

thanks,

Don Curtes

[Terry D.]

Re: Crankcase Oil

Don
Try searching the archieves, this topic has been discussed several times. Make sure you check out articles written by Duke. It usually comes down to personal preferrence as I don't think there is only one brand to use. I use Shell Rotella 15W40 in my 62.
Terry

[Lyndon S.]

Re: Crankcase Oil

I like to use Mobil Delvac , but like Duke says you can buy the house brand at Wal-Mart.
__________
Kelly

[Duke W.]

Re: Crankcase Oil

You guys fail the course! Your answers are incomplete and misleading.

Maybe someone else can list the TWO SELECTION CRITERIA for vintage Corvette engine oil.

I will state - as I have a zillion times before - that brand name is irrelevant, immaterial, and of absolutely no consequence as long as you follow the TWO SELECTION CRITERIA.

Does anyone know them?

To the OP - do you have the Summer 2008 Corvette Restorer?

Duke

[Lyndon S.]

Re: Crankcase Oil

I don’t understand how I failed the course? I suggested a Diesel engine oil, I like Mobil Delvac. I live not to far from the refinery that makes Mobil 1 and I have several friends that work there and from time to time I get goodies from them. I also like the black jugs that the Delvac comes in they look good on my shelf in the garage.
__________
Kelly

[Steven B.]

Re: Crankcase Oil

You guys fail the course! Your answers are incomplete and misleading.

Maybe someone else can list the TWO SELECTION CRITERIA for vintage Corvette engine oil.

I will state - as I have a zillion times before - that brand name is irrelevant, immaterial, and of absolutely no consequence as long as you follow the TWO SELECTION CRITERIA.

Does anyone know them?

To the OP - do you have the Summer 2008 Corvette Restorer?

Duke

Memory serving, or maybe not, I look for 1) CJ-4 or CI-4 and 2) the appropriate viscosity.

[Duke W.]

Re: Crankcase Oil

A gold star for Steven! That's the answer - short and simple.

The "appropriate viscosity" is based on the lowest cold start temperature, and virtually any GM vehicle owner's manual from the fifties to the seventies has appropriate viscosity - cold start temperature information.

Duke

[Ralph E.]

Re: Crankcase Oil

First let me say.
I use HD Diesel Oil 15W-40 CJ-4 or CI-4 in my Corvette.
Recently I was at an engine rebuilder shop and I told him what oil I was using in my old 67 Vette. He went off! said I was crazy. Said that Diesel oil is to "heavy" for car engines and should never be used.
I listened as he went on and on. I knew Duke would never steer us wrong.

Not sure why, but this year I did not need to top off my engine oil once. In addition, the engine is running cooler. Could this be the HD diesel oil?

[Joe R.]

Re: Crankcase Oil

Hey, your engine builder is from the old school like myself and others on this board.

Viscosity hasn't changed in the last 100 years unless they have re-written the rule book!

I use Rotella-T 15-40 in my Dodge diesel truck. Mobil 1 10-30 in my 96 Corvette. Castrol 10-30 in my 1967 Corvette. The truck has 350,000, the 96 Corvette has 150,000 and the 67 doesn't even have 50K on it.

The above are all good oils and when used with the proper viscosity for the application and changed regularly the motors will last a lifetime. I live in the South and don't need the 5W oils for starting in the winter.

JR

[Duke W.]

Re: Crankcase Oil

First let me say.
I use HD Diesel Oil 15W-40 CJ-4 or CI-4 in my Corvette.
Recently I was at an engine rebuilder shop and I told him what oil I was using in my old 67 Vette. He went off! said I was crazy. Said that Diesel oil is to "heavy" for car engines and should never be used.
I listened as he went on and on. I knew Duke would never steer us wrong.

Not sure why, but this year I did not need to top off my engine oil once. In addition, the engine is running cooler. Could this be the HD diesel oil?

Again, look at any period owner's manual to see what viscosity is suitable for for your lowest cold start temperature, and understand that a muli-vis oil like 15W-40 means it has the viscosity of a 15W at 32F and a 40 at 212F.

Back in the seventies and 80s everyone was using 20W-50 "racing oil". Was it too heavy?

I wish I had a buck for every moronic statement made by some "engine builder".

Guys change oil viscosity and claim it runs -hotter, colder, higher oil pressure, lower oil pressure, quieter, noisier...

Given the accuracy of indash gages any difference between a 10W-30 and 15W-40 is either a figment of your imagination or your engine is the home of a tribe or gremlins.

Duke

[Duke W.]

Re: Crankcase Oil

Castrol 10-30 in my 1967 Corvette.
JR

Why are you using an S-category oil in a vintage Corvette?

Duke

[Don C.]

Re: Crankcase Oil

thanks to all for their input. This was my first post and the responses were very gratifying.

Don

[Paul J.]

Re: Crankcase Oil

Don:

Today it's pretty much a matter of preferrence. Consider how much you use the car and in what temperatures. The previous answers about viscosity is sage advice.

I used to be semi-expert on motor oil, but I had forgotten most of what I knew as the products changed. When I heard myself talking to somebody a few years back about the cold starting characteristics of parafin based-crudes and the aggressive acids in asphalt-based crudes, I decided it was time for a refresher. If you go to the oil companies' websites you can look at the MSDS sheets and see the characteristics of all of the different oils, as well as find information on the additives. You will see that they are all very similar. The difference is not in the types of the additives in the oil, as they all do the same things, but how effective the additives in one particular oil are at doing what they are supposed to. The previous posts discussing the different graded oils is primarily about the performance of the additives.

I've used several different brands of conventional oil over the years with no problems. On vehicles that I do not start often I use STP because it leaves a film on polished surfaces such as bearings. This film becomes more viscous as it cools, and stays put. This provides some additional protection at start-up.

When I finish my Vette restoration, I will probably use a synthetic for longevity. But remember, most of the dirt you see in oil are particles that got past the filter and can cause additional wear in the engine.

Time for me to get off my horse and shut up.

Paul

[Clem Z.]

Re: Crankcase Oil

Don:

Today it's pretty much a matter of preferrence. Consider how much you use the car and in what temperatures. The previous answers about viscosity is sage advice.

I used to be semi-expert on motor oil, but I had forgotten most of what I knew as the products changed. When I heard myself talking to somebody a few years back about the cold starting characteristics of parafin based-crudes and the aggressive acids in asphalt-based crudes, I decided it was time for a refresher. If you go to the oil companies' websites you can look at the MSDS sheets and see the characteristics of all of the different oils, as well as find information on the additives. You will see that they are all very similar. The difference is not in the types of the additives in the oil, as they all do the same things, but how effective the additives in one particular oil are at doing what they are supposed to. The previous posts discussing the different graded oils is primarily about the performance of the additives.

I've used several different brands of conventional oil over the years with no problems. On vehicles that I do not start often I use STP because it leaves a film on polished surfaces such as bearings. This film becomes more viscous as it cools, and stays put. This provides some additional protection at start-up.

When I finish my Vette restoration, I will probably use a synthetic for longevity. But remember, most of the dirt you see in oil are particles that got past the filter and can cause additional wear in the engine.

Time for me to get off my horse and shut up.

Paul

when i switched from the factory fill at 4000 miles on my new at the time 1988 silverado to mobil 1 i noticed that the oil became dark very quickly. i called mobil about this and they told me the mobil 1 was doing its job cleaning the internals of the engine. at 150,000 miles is still use mobil 1 but i save it from my corvette which only gets the max of 4000 miles a year where i change it every fall before storage. i change once a year in the truck and that is about 6000 to 8000 miles. remember i am retired and living on a fixed income. if you look thru the oil fill cap into the cylinder head the surface looks like band new. also the truck has flat tappet hydraulic lifters and so far no problems with camshaft wear.

[Paul J.]

Re: Crankcase Oil

That's very interesting, Clem. While I probably would'nt do what you're doing, I don't see any big problems with it. The evidence of the lack of dirt deposits and formation of resins on the head is probably a fair indicator that there is not any premature significant engine wear.

You're certainly making the most of your resources, and helping the planet too.

Paul