Duke, SL oil question

[Michael F.]

How does SL diesel compare to the CJ4, same, better or worse for our cars, thanks.

[Clem Z.]

Re: Duke, SL oil question

How does SL diesel compare to the CJ4, same, better or worse for our cars, thanks.

back in the 70s i had a customer wear out a BBC race engine in 2 races because he used "series 3" diesel engine oil

[Michael W.]

Re: Duke, SL oil question

The 'S' in 'SL' is for spark engines. The 'C' in 'CJ' is for compression engines, ie. diesels. I think.

[Duke W.]

Re: Duke, SL oil question

SL is NOT a "diesel oil". It was the first API spec to limit P - 0.10%. The CJ-4 limit is 0.12%. SL was the last S-category oil I used in my cars. Once I found out about the P limit, I switched to C-category.

You need to read the engine oil article.

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

Duke

[Dick W.]

Re: Duke, SL oil question

back in the 70s i had a customer wear out a BBC race engine in 2 races because he used "series 3" diesel engine oil

Series III oil was basically for Detroit Diesel two stroke cycle engines. I do not remember the main diferences but I do know that it had a lower ash content. If you put good oil in those old engines, you might as well carry a five gallon bucket with you for add oil

[Clem Z.]

Re: Duke, SL oil question

Series III oil was basically for Detroit Diesel two stroke cycle engines. I do not remember the main diferences but I do know that it had a lower ash content. If you put good oil in those old engines, you might as well carry a five gallon bucket with you for add oil

this guy owned a bunch of dozers,graders and other stuff with diesel engines so he figured it was good enought for that stuff should be good enought for the race engine. i even gave him a case of D-A speed sport oil when he picked up the engine. stupid is as stupid does.

[Duke W.]

Re: Duke, SL oil question

There were specific API C-category specs for those old Detroit Diesel two-strokes, but I believe they are long obsolete.

I know there are a lot of old Detroit Diesel two-strokes still in marine service, but I have no idea what currently available oil they should use.

"Low ash" means low additive levels since it's the additives that leave ash, not the base oils. So "low ash" is a no-no for vintage automotive engines with sliding surface valve trains that you want to last. This includes current aviation oils and old two-stroke diesel oils.

Here's a link to the latest edition of the API Engine Oil Guide that shows the history of both C and S-category oils from the beginning of this system's use, circa 1969, to the present:

http://www.api.org/certifications/engineoil/categories/upload/MOTOR_OIL_GUIDE_2010_120210.pdf

Duke

[Michael F.]

Re: Duke, SL oil question

thank duke and others.