327 - 365HP Motor Oil Viscosity

[David K.]

Hello to all;

I have purchased a 65', with a 365hp engine, showing 75,000 miles. The engine was rebuilt 30 over; at 60,000 miles. When I picked up the car last week, we changed the oil and filter & the vendor recommended non-synthetic, with a 20-50 weight.
I have not run the car yet, and was questioning if this is too thick of a grade.
My second question is regarding gasoline. There is a lot of discussion regarding the Ethanol content in gas these days, and the fact that this can damage the older engines. Any comments would be greatly appreciated !
Thank you in advance; David Kalaydjian. Montreal; Canada

[Michael W.]

Re: 327 - 365HP Motor Oil Viscosity

Hi David-

Greetings from a former Montrealer- that's Art Armstrong's former car you've purchased. Very nice machine indeed.

There's no need to use 20W50, use 10W30 or 10W40. Of far greater importance is ensuring the oil has sufficient zinc and phosphorus (ZDDP), unfortunately very few modern oils are suitable. Read Duke's article starting on page three:

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

Then head over to Walmart to stock up on Rotella.

Regarding gas- Eastern Canada has had E10 gas for at least 20 years with most drivers being unaware that they were using it. Much of North America has had it for 30 years. Actual engine problems attributed to ethanol are almost unheard of- I've never had one moment's worth of problems. I'm sure you'll hear all sorts of 'sky is falling stories' that want to blame anything and everything that's gone wrong in their life on the fuel.

BTW- I've asked the NCRS Quebec Chapter Chairman to get in touch with you assuming you're not already a member.

Mike

[Jim T.]

Re: 327 - 365HP Motor Oil Viscosity

David after reading Duke's information years ago I started using Rotella 10W30 diesel oil when I could find it. For a few years now all I can find on shelves is 15W40 diesel oil which I do use. NAPA told me they can order 10W30 Rotella, but I have not ordered it from them. 1968 327/350 and 1985 Corvette.

[David K.]

Re: 327 - 365HP Motor Oil Viscosity

Thank you guys; I'll switch back to 10-30 on the next oil change. In the meantime, is it fine to run the car with the 20-50 we just installed - or can this cause damage or any sort ? I'll probably run 2000 miles with it........
Regards from Montreal; David

[Joe R.]

Re: 327 - 365HP Motor Oil Viscosity

David,

What API category is the 20-50 oil? If it's not CJ-4, you run a good chance of flattening your cam. Don't ask me how I know!

Joe

[Mike E.]

Re: 327 - 365HP Motor Oil Viscosity

I think Duke's choice currently is Walmart brand generic CJ-4. I checked my local store and they have it.

Mike

[Don H.]

Re: 327 - 365HP Motor Oil Viscosity

Duke does not like to waste money on boutique oils. This one does the job, without costing a small fortune. My 365 hp engine likes it.

[Michael W.]

Re: 327 - 365HP Motor Oil Viscosity

Duke does not like to waste money on boutique oils. This one does the job, without costing a small fortune. My 365 hp engine likes it.

Don-

For whatever reasons, the Wally Worlds in Canada don't seem to stock their house brand of CJ4. They do carry Rotella though.

[Mike E.]

Re: 327 - 365HP Motor Oil Viscosity

Don-

For whatever reasons, the Wally Worlds in Canada don't seem to stock their house brand of CJ4. They do carry Rotella though.

Could be the colour of the container even though it's Duke's favourite brand. Eh?

Mike

[Michael J.]

Re: 327 - 365HP Motor Oil Viscosity

I can't tell you how many arguments I have started on other TDBs by pointing out and endorsing Duke's frugal wisdom, most just won't "buy it", if you know what I mean...but as a 30+ year, retired major oil company employee, who likes to see my stock do well with higher profits, I guess I shouldn't complain when people want to overspend and waste money on the oils.....

[Michael W.]

Re: 327 - 365HP Motor Oil Viscosity

Could be the colour of the container even though it's Duke's favourite brand. Eh?

Mike

OK, you'll have to give me a clue. ??

[Mike E.]

Re: 327 - 365HP Motor Oil Viscosity

OK, you'll have to give me a clue. ??

Just messing with the way you guys spell things funny...I know...We're the ones the spell things funny....Right?

I go back and forth with some the folks in Canada on a home theater forum about this. Sometimes I forget where I'm at, sorry.


Mike

[Michael W.]

Re: 327 - 365HP Motor Oil Viscosity

Just messing with the way you guys spell things funny...I know...We're the ones the spell things funny....Right?

I go back and forth with some the folks in Canada on a home theater forum about this. Sometimes I forget where I'm at.


Mike

You guys do like to be unique in all sorts of ways. Given that the market for CJ4 oils is comparatively small, possibly Wallmart figured out that printing up bilingual labels that would show contents in litres and real gallons was not worthwhile.

[Robert K.]

Re: 327 - 365HP Motor Oil Viscosity

The best standard oil )without special additives) is the 15w40 HD as mentioned above. Many years ago, probably the 70s, A friend was at an Oldsmobile national dealers convention as a shop managers and the topic turn to the fried cam shafts in the 350 engine. My friend said he had never heard of the problem. At break he call the dealership and asked and they had ever had a wiped cam in that engine, answer was no. Olds sent a team out to this dealership (Paul Brothers in DC) to determine why. The result was that the dealership used Quaker State 15w40 HD for all oil changes. It had been suggested by the owner of the Quaker State distributer. He said it was a better oil and was the same price, so they switched. Oldsmobile issued an immediate service announcement to use only 15w40 in that engine. It has often been suggested as the best oil for 327/365 solid lifter engine.