Adding Zinc To Crankcase

[glcaines]

I have restored several classic cars in the past and I've always added Lucas Zinc Plus with ZDDP to the crankcase when I change oil due to the lack of zinc in modern motor oil. Is this practice recommended for the M151A2 engine?

[Horst]

we have an expert on oils on this forum, let's see what he will come up with...

[rickf]

The preferred oil to use on any older car nowadays is 15W-40 diesel motor oil. These oils have more sulfur and zinc in them than the automotive oils that have had it removed to prevent damage to catalytic converters. But now that diesels are going with converters I am not so sure that they may not be cutting back in those oils soon. Raymond has the inside line on this stuff since his family was in the oil business for many years up until quite recently. I am sure he still stays up to date on it. I use Rotella oil exclusively in all of my vehicles except for the newer ones. I buy it by the pallet of five gallon pails. Then again I do have a lot of diesel vehicles and equipment. But there is also Delo and other brands. You definitely want to stay with a well known brand name, do not go with the el-cheapo stuff from Wally world or the store brand from the parts store!

[glcaines]

I purchased Shell Rotella SAE 30 oil for the M151A2. I also have a lot of diesel vehicles, car, pickup, M35A3, 2 JD tractors and a military generator and I have always used Rotella straight SAE 30 in all of them. I like to be able to use the same oil in everything. When I was in the Army, SAE 30 went in everything.

[Mr. Recovery]

I use Rotella also; I was given this mug for asking for Rotella at the Truck stops when I was driving the big riggs.

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[rickf]

Is the Rotella 30 diesel rated? If not then it is the same as any other automotive motor oil. I will look it up tomorrow, it is late and I am tired.

[raymond]

Certainly not going to hurt anything adding that supplement to your crankcase.
Not sure if zinc is being cut from modern diesel formulations, but would be surprised if so, as diesel engine oils are backwards compatible and also used extensively in off road diesel motor applications where convertors are typically not used.
These engines also are used in heavy load applications where maximum wear resistance would be needed.
By and large, they also still use regular valve lifters and standard camshafts so ZDDP would still be necessary for long term wear resistance,...although since I have not kept up with this in years, there could be a replacement for it that has been instituted.
Would suspect it would have been publicized by now if one had been found.

Years ago when this first started being discussed, I called Shell's lubricant division in Houston and asked about zinc content in Shell's Rotella diesel oil line and whether it would be suitable for use in older gasoline engines. The engineer I spoke to said it still had a very high zinc content because of it's intended use and would more than adequate for older engines where higher zinc passenger car motor oils were specified.

As Rick said, we sold the business some time ago so I no longer have contacts I used to have nor receive any of the trade magazines so I have not really been keeping up with modern API specifications.

I personally use Shell's Rotella T-6 5w40 (not the 15w40 or 10w30) full synthetic in just about everything I own from my push mower to my tractor, to my Yamaha 150hp outboard, to my Seadoo GTI 130 jet ski, to my propane back up house generator, to my power washer in both the motor and pump.
I even run it in my F150 with the dual turbo charged v6.
I run it because diesel engine oils have a history of having to stand up to the heat a turbo charger produces.


The problem with cutting back (the amount was cut back, not eliminated) of zinc in motor oils first manifested itself when English sports cars started having valve/camshaft interface wear problems.
Seems the English were not surface hardening steel to the extent the rest of the industry was.
So cuts in anti-wear additives showed up there first.

[glcaines]

The Shell Rotella SAE 30 I use is labeled as Heavy Duty Diesel Oil. There is nothing on the label indicating zinc content, but the label does state it is suitable for both turbo and non-turbo older diesel engines, both on-road and off-road. I've rebuilt and restored several old British sports cars in the past and that is when I started using the Lucas Zink Plus with ZDDP and I've never had any camshaft problems like some other people I know. I think I'm going to go ahead and add the Lucas Zink Plus to my M151A2 as I don't think it could hurt. I've had good luck with the Rotella SAE 30 over the past few years. Thanks for the feedback.

[rickf]

I was just in Tractor supply today and I saw the Rotella 30 weight and yes, it is a diesel rated oil so the same additives apply as in the multigrade oils. My 96 Ford F350 diesel has 450,000 miles on it and it runs and sounds like new. Perfect oil pressure and original injectors, which run on the oil from the high pressure pump. So that tells me something about the Rotella 15W-40 diesel oils!! That truck has not led a grocery getter life for sure.