Oil?

[Robert G.]

Hi All,
I may be making too much of this, but I recently bought a '65 (327/300 hp) which has needed a fair amount of sorting. I had the engine rebuilt and am getting ready to re-install it.
I have heard conflicting reports although it is pretty much universal to use a conventional oil instead of synthetic or partially synthetic. I also know that the oil has to have a high level of zinc and phosphorus.
Joe Gibbs racing division has suggested their HR 10W-40. Some other Corvette owners have said to use Shell Rotella T-4 15W-40 which as I'm sure you know is a diesel engine oil but has the proper levels of zinc and phosphorus, but others have said not to use it because of the extra diesel additives.
What are all your takes on the oil to use?
Thanks for Your Help,
Rob Goodrich (65905)

[Mark E.]

Re: Oil?

Rob,

You're fairly new to this forum so you should get a pass with this question. This is a well hashed topic; if you do a search you'll find hours of reading entertainment. Have fun and let us know what you decide.

[Don H.]

Re: Oil?

Rob
If you search oil in the search box under Society above, you get nothing. But if you search Rotella, you will get enough replies to keep you busy reading until this darned pandemic is resolved.
Here is just one recent thread with pages of responses. Good luck in your decision on which oil to choose. https://www.forums.ncrs.org/showthre...hlight=Rotella

oops, I took too long searching.....

[Frank D.]

Re: Oil?

I haven't heard at all that there is a consensus about using dino oil over synthetic; only that the right amounts of zinc and phosphorus are in the oil.

[Tom M.]

Re: Oil?

https://stlouisncrs.org/news_files/St_Louis_NCRS_Chapter_July_2011.pdf

There is a follow-on article out on the interweb that addresses the newer CK diesel oils address the same needs as CJ diesel oils referenced in the pdf.

[Robert G.]

Re: Oil?

Thanks Dan there are a lot of comments. Guess this discussion has been going on for some time and with no end in sight

[Robert G.]

Re: Oil?

Oops, sorry I meant Don

[Robert G.]

Re: Oil?

Thanks Frank, that's what I'm hearing.

[Robert G.]

Re: Oil?

Tom thank you, interesting article and at times very technical. Seems the gist of it is spend the money for $8-$9/quart oil if you want to waste your money or go to Walmart and buy Shell Rotella T4 for $13+/gallon.
Could I please ask you another question? I probably should change the gear lube in both the transmission (4-speed) and the differential which is 3.36:1 and positraction. I imagine regular gear lube is good for the transmission, but what about the differential? Is current positraction fluid good or is an old type better.
I don't know if you can e-mail me your thoughts or if you have to go through the forum.
Much Appreciation for Your Help,
Rob
robgoodrich49@gmail.com

[Tom E.]

Re: Oil?

Robert,
here is a link from the Petroleum Quality Institute that lists most of the CK4 oils on the market. You can click on each one and see the test results and make an informed decision on which oil you want to buy.
Tom

https://pqia.org/heavy-duty-diesel-engine-oil/

[Frank D.]

Re: Oil?

Tom thank you, interesting article and at times very technical. Seems the gist of it is spend the money for $8-$9/quart oil if you want to waste your money or go to Walmart and buy Shell Rotella T4 for $13+/gallon.
Could I please ask you another question? I probably should change the gear lube in both the transmission (4-speed) and the differential which is 3.36:1 and positraction. I imagine regular gear lube is good for the transmission, but what about the differential? Is current positraction fluid good or is an old type better.
I don't know if you can e-mail me your thoughts or if you have to go through the forum.
Much Appreciation for Your Help,
Rob
robgoodrich49@gmail.com

I use this i the differential - non-synthetic (which is getting harder to find):

https://www.amazon.com/gp/product/B000M8RYMC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Along with GM posi-additive

As to the transmission, I won't get into the GL4/GL5 debate beyond saying I just use GL4 products.

[Robert G.]

Re: Oil?

Tom,
Thanks for the link and information.
Rob

[Duke W.]

Re: Oil?

Tom thank you, interesting article and at times very technical. Seems the gist of it is spend the money for $8-$9/quart oil if you want to waste your money or go to Walmart and buy Shell Rotella T4 for $13+/gallon.
Could I please ask you another question? I probably should change the gear lube in both the transmission (4-speed) and the differential which is 3.36:1 and positraction. I imagine regular gear lube is good for the transmission, but what about the differential? Is current positraction fluid good or is an old type better.
I don't know if you can e-mail me your thoughts or if you have to go through the forum.
Much Appreciation for Your Help,
Rob
robgoodrich49@gmail.com

It's not clear to me that you read my oil article, but if you did you should understand that you buy the API service classification, NOT a specific brand. Usually Walmart' SuperTech 15W-40 CK-4 is less expensive than any of the national brands, Delo, Delvac, and Rotella, but sometimes one might be on sale. I buy the least expensive.

The primary advantage of "synthetics" is longer service life in terms of miles, but since most vintage cars are not driven frequently, they accumulate mileage slowly, so changes should usually be done on a time basis like one two years if the car acculturates less than 1000 miles per years. Most "synthetics" also have a wider viscosity range, so the range of "synthetic" CK-4 us 5W-40; 15W-40 is fine for CONSISTENT cold starts down to about 15-20F, however, since most are not driven in weather this cold 15W-40 is more than adequate viscosity range.

The original manual transmission and axle oil spec is Mil-L-2105D. This was replaced in the seventies with the commercial API spec 80W-90 GL-5. As with engine oil, BRAND MAKES NO DIFFERENCE. Buy the least expensive product that meets the API 8oW-90 GL-5 spec.

The four-speed transmission capacity is 2.5 pints and 3.7 pints for the axle. Positraction axles also require at least one four-ounce bottle of friction modifier, which is sold under many different brands. You don't have to buy if from a GM dealer. The NAPA part number is NCB4285V.

Duke

[Robert G.]

Re: Oil?

Frank,
Thanks again for helping out.
Rob

[Mark E.]

Re: Oil?

Rob
If you search oil in the search box under Society above, you get nothing.

This looks like a search function bug the administrators should look into. There should be scores of hits.