Engine oil

[buick8791]

What engine oil you recommend for Buick GN ´87 to day?

I have used some oil 5w40 with CompCams oil additive stuff actually intended for cam running in but I mean now the daily driving. The cam is the original, not an roller cam.

The car is in the use only in the summer times the temperature being about 10-25 Celsius degrees. So what oil and what oil additive is good?

[Blue Bowtie]

Diesel-rated oil and/or ZDDP additive in "regular" oil is probably sufficient for cam and lifter wear protection. The turbo might like some synthetic in the bearings as it likely has a more stable VI, and turbos do get hot.

[buick8791]

Hi, and thank you for your answer!

But, what is your recommendation for the viscosity for the plus temperatures above?

And, is STP zinc oil additive better than CompCams additive stuff, which is actually intended for cam running in? I mean the oil additives used for daily driving?

And in addition, how about Valvoline vr1 10w-60 oil, please see my question about the viscosity above?

And which synthetic diesel oil you will recommend( I understood, that it would be anyway synthetic)? Brand and viscosity?

Thanks!

[Blue Bowtie]

Mobil Delvac Extreme is safe, rated for turbos and injection pumps, and readily available. It contains about 1,600 PPM ZDDP (zinc dialkyldithiophosphate) for wear protection. 10W30 should be a good start since the synthetic has a lot better viscosity index (stability), so SAE 60-some mineral oil isn't necessary, and that high a viscosity may not feed through a turbo's sleeves very well anyway.

STP may not get it done. There are specific additives containing a solution of ZDDP, esters, and a carrier oil. Rislone 4405 is one such preparation, and one bottle can bring up the ZDDP concentration of five quarts of oil to around 1,500-1,800 PPM. https://rislone.com/wp-content/uploa...4405-PDS-1.pdf

It may be more cost effective to just go with the Delvac and call it done instead of another fifteen bucks for the additive to turn "plain" oil into something suitable for a flat tappet cam.

I have an '86 TA, the last year for the SBC to have a flat tappet. I've been running the Mobil in that for a couple decades just to protect that cam, but in 15W-40 since it only sees summer use.

[buick8791]

Hi,
and thanks for your answer!

So, I will check if I find in my country that Mobil delvac and zddp additive(if needed that additive) , which you have recommend.

Our GN see only the summertime also, temperature being 10-25 plus degrees.
So is the viscosity 10w30 ok? I will ask, because you use 15w40 grade oil in summertime. Of course in USA is very hot summers depending on the area, where you use your TTA.

If that Mobil 10w30 is ok for me, so it doesn´t need any additive or how?

Thanks again!

[buick8791]

Hi,

and thanks a lot for the good information Blue Bowtie!

I will check if I find the suitable oil you suggested.

BR,

buick8791