Do Volvo engines require an oil with a higher zinc content even if they are overhead cam engines, since the zinc levels have become less in recent years? I'm currently running Castrol 10-30.

 

Oregonite:
Great question! I would like to know the answer myself. If you are game, you might consider posting this on bobistheoilguy.com website. I have been looking at this website for years. There are people like me who are not engineers and just read it for a hobby and to know more about my own vehicles mixed with engineers, engine rebuilders, tribologists, etc...I'm actually addicted to it as a novice DIYer.
I suggest being more specific about the engine you are interested in, i.e. red block, 5 cylinder, whatever.

 

I'm referring to the '94 B230FT Red Block engine, and any non roller overhead cam engine.

 

You know...I did a cyl head swap ( B21F) and found my old head to be EXTREMELY CORRODED (aluminum head) and the donor head with only 3 years in production difference was almost intact...but I noticed a high quality coolant was used....

NOW I BOUGHT THIS COOLANT FOR HIGH MILEAGE ENGINES THAT HAD "ZINC" TO RE-COAT PREVENT CORROSION AS "ZINC" BINDS WITH ALUMINUM...IF ADDED IN THE BEGINNING OF THE CYL HEAD FORGING....?
AND FOUND THIS INFO:
Many alloys contain zinc, including brass, an alloy of copper and zinc. Other metals long known to form binary alloys with zinc are ALUMINIUM, antimony, bismuth, gold, IRON, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium and sodium.[11] While neither zinc nor zirconium are ferromagnetic, their alloy ZrZn2 exhibits ferromagnetism below 35 K.[6]

So if the RedBlocks were forged and zinc was part of the ingredients added...then an oil with zinc additives might help...?

 

Oregonite, that is a question that you may find the answer to with a search on BITOG. But I can give you a short answer. ZDDP is the zinc compoud that has has been added to motor oil for many years and is known to put a tough,durable microscopic layer on bearings, journals, etc. However, with the most recent API Automobile oils, it has been mostly eliminated.
Why, do you ask, would oilmakers remove such a proven material from their products? It's because the phosphhorus (the P part of the name ZDDP) is volatalized during combustion and combines with one of the catalysts in your catalytic converter and eventually makes it ineffective.
So, for most of us folks that use API oils, that leaves us with the choice of just doing without ZDDP(and still getting excellent lubrication charactaristics)and keeeping our cars with a good cat and passing emissions testing; or if perhaps you don't need or have a cat on your car, usung an oil designed for racing or motorcycle use. Those will still have ZDDP (Some claim high levels).
That also begs the question-What if I just run a cycle of racing oil in my cat equipped car for say 1k or 2k miles to establish a stable base on a new or rebuilt motor? Will just that destroy my cat? I don't know the answer; maybe someone here does.
In my opinion I think it is not worth the risk of trashing a cat , especially here in CA where we have to install pricey, CARB approved replacement cats .
Your car being a 1994 possibly has a good base layed down already; I do know that my 86 245 has gone approx 400k miles on API dino oil. I wouldn't worry about it. There are many other things that will break on that car before a well-maintaned redblock motor will die.

 

You don't necessarily need a high zinc oil but if you prefer to use one than Shell Rotella would be a good one to use.

 

most of the oils today, like rotella, with high zinc are diesel oils and are too heavy of a weight for redblocks, which prefer 10W30 in most climates.

 

Do I need to run a zinc additive with the Castrol GTX 10W30 I am currently running? Is the zinc content that critical in the Redblock engines?

 

i've been using mobil 1 10w30 in our various b230's for years, without any oil related issues

 

I've been using 10W-40 Castrol or Valvoline oil from the beginning . We bought our 89 740 new and it now has 349K miles on it and I have not seen any unusual wear during any of my tune up , specifically valve adjustments. The engine is still pretty strong and other then some oil leaks it doesn't use more then 3/4 of a quart every 5000 mile oil change. This same issue came up on my Ferrari site and it didn't seem to matter if the zinc content was an issue. By the way I picked up the Volvo piston slap around 200K miles so sometimes at idle it sounds like a diesel but we learned to live with it. Maybe if we reach 500K I'll take it apart and rebuild it.