Newbie Q's

[OilSnob]

I've been reading myself to sleep over the last several weeks

with the many great resources available here and have a few elementary Q's that i wasn't able to satisfy so with a bit of help I might win a argument or two concerning flat lifter engines on a different forum

I'm not afraid of diesel oils in old(60's) gas cars but have usually just used them for short intervals after a coma for instance but now with all the new spec reformulations for pcmo I will begin to use them more regularly. So i'm sold both scientifically and anecdotally. I've been down the MC, VR1 and Amsoil road and am tired of "it makes me feel better to spend more". I currently have some 20W50 Castrol Actevo 4T (didnt read ahead enough) in a '66 289 i can't wait to drain out!
Despite what some "old mechanics that have talked with oil engineers say so," What is the worst that can happen from using a HDDO? Ive heard "washed" bearings or deposits dislodged that will clog passageways or oil pumps.
If you compare Rotella to VR1 you see similar levels of Ca, but what might be in an HDEO that will not show up in a UOA that I don't know about?

I currently have some Valvoline 15W40 and a bottle of LM #2009 waiting till I finish another job to drain the Actevo and pour it in

Thanks for rehashing with me.

 

[OilSnob]

...One of the references i found cited on both Joe Gibbs Driven and other places that want to sell their oils instead of using a diesel oil is Lubraction Science: Additives and valve train wear. The boutique oils say that the additional "metallic detergents" will interact with ZDDP in a negative way in regards to the decomposition temperatures. Well i found that journal article and read it and what I took away concerning this decomposition temps is there is only a 10*c difference with overbased calcium which 10*c I regard as minimal on engines not used for DD or short trips. So they cite a potential problem and not a "how I drive problem," did I comprehend that properly?

 

[ZeeOSix]

Flat Tappet Oil Requirements

https://www.highpowermedia.com/RET-Monitor/3713/flat-tappet-engines-and-their-oil-requirements

 

[OilSnob]

So whats up? Too much too soon, bad question, no real answer, answered somewhere I cant find or didn't provide the right secret handshake?

 

[BigShug681]

I'm not 100% sure what you're asking? If it's just what will happen if I use diesel oil in a gasser the short answer is nothing. If you have cats then some of the higher ZDDP formulations may cause premature failure of the kitties if you burn an excessive amount of the oil.

 

[kschachn]

Originally Posted by OilSnob
So whats up? Too much too soon, bad question, no real answer, answered somewhere I cant find or didn't provide the right secret handshake

?

 

[OilSnob]

So to be more concise.
Whats the worst that can happen using it? (I don't think any but not sure.) from any or maybe the most extreme diesel blend? Where might these rumors of failures be based upon?

What may be in them(or any oil for that matter) that will not be evident in an oil analysis?

 

[dave1251]

Do you realise the 60's era motor oils had the same or less amount of ZDDP as today's oils?

 

[Gokhan]

I ran 15W-40 in my 85 Corolla in the past for many OCIs. It's fine. It's very thick but old engines like yours would benefit from thick oil. You can't do extended OCIs with it though because it's conventional oil.

HDEO cleaning better is an old wives' tale. It's conventional oil after all. If you want cleaning, go with Mobil 1 or similar synthetic oil that contains PAO and ester.

If you want synthetic and thick, there is this:

https://www.chevronlubricants.com/en_us/home/products/delo-400-xsp-sae-5w-40.html