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Is it ok to use a multi-grade oil like the Lucas 10w-30w for older motors? It has the Zinc additive already in it. Or should I run straight 30w non-detrgnt & add the zinc to that? If it makes any difference, I'm running a stock cuno oil filter in a 1951 M38 flathead. Thanks, Smitty:?:

Rather then make a quick guess and pick from the majority of opinions you may receive here why not google "engine oil and older engines" and learn for yourself the importance of sticking with oils blended specifically for classic engines that have needs unlike modern engines. Same goes for your tranny and transfer lube needs.

At this link is a good article by Castrol outlining some of the specific needs and considerations of our older engines when it comes to oil:

http://www.castrol.com/en_gb/united-kin ... -oils.html

Thanks for the advice. I did the google search and checked out the Castrol site. I'm more confused than ever. I tried the Castrol site & found Classic XL 30. I can't find anyone in the U.S. that sells it. What do you guys run in your Jeeps? Smitty

The oil manufacturer is the second place to go for information on what oil is best for your car. The first place to go is an independent study. These are usually found on car club and antique/classic restoration sites. Heres a few that should set your mind straight and dump all the confusion you say your are suffering from.

http://www.oldcarsweekly.com/restoratio ... d_old_cars

http://www.centralpastreetmachines.org/ ... 20Oil.html

http://www.bellperformance.com/blog/tip ... lassic-car

http://blog.hemmings.com/index.php/2012 ... r-engines/

These all make it very clear that the problem with todays oils is their reduction in Zinc & Phosphates due to EPA restrictions, catalytic convertor contamination and lower internal engine frictions on modern engines. These new oils cost old classic engine owners higher wear rates in their valve trains and more corrosion issues.

What oil to get? Get a quality oil in a weight you want that meets the two older specifications SG or SL. Do not use SM Rated oils. Or buy oils that state they are specifically engineered for antique/classic engine.

wesk wrote:The oil manufacturer is the second place to go for information on what oil is best for your car. The first place to go is an independent study. These are usually found on car club and antique/classic restoration sites. Heres a few that should set your mind straight and dump all the confusion you say your are suffering from.

http://www.oldcarsweekly.com/restoratio ... d_old_cars

http://www.centralpastreetmachines.org/ ... 20Oil.html

http://www.bellperformance.com/blog/tip ... lassic-car

http://blog.hemmings.com/index.php/2012 ... r-engines/

These all make it very clear that the problem with todays oils is their reduction in Zinc & Phosphates due to EPA restrictions, catalytic convertor contamination and lower internal engine frictions on modern engines. These new oils cost old classic engine owners higher wear rates in their valve trains and more corrosion issues.

What oil to get? Get a quality oil in a weight you want that meets the two older specifications SG or SL. Do not use SM Rated oils. Or buy oils that state they are specifically engineered for antique/classic engine.

Thanks Wes! I wound up getting Valvoline 30w racing oil with Zinc in it. I plan on using this oil in my Model A Ford as well. Thanks again.

FWIW, I use Shell Rotella 15W-40 with an additive called ZDDPlus. This additive brings the phosphorus and zinc levels up to that of older blends of motor oil that were used in engines having flat tappet lifters. Modern oil blends have very low concentrations of zinc and phosphorus.

x2 on Shell Rotella

You could also add a zinc additive, Amazon has MPT MPT-323 ZDDP Zinc Additive - 4 fl. oz. for about 10$

You can easily overthink the oil issue. I've been using Shell Rotella T 15w40 for years in both my 1953 Ford Tractor and 1952 M38A1. It has the all important Zinc-phosphate additives that your engine needs. I found this online: "Shell Rotella T is a conventional (mineral-based) oil that was originally formulated for diesel engines. Rotella T still contains 1,200 parts per million ZDDP, according to Shell – which is as much as five times the amount found in other oils." Rotella T is readily available and moderately priced. Here in farming country there are a lot of old tractors and motorized implements so they sell a lot of Rotella. Tractor supply even sells it in 5 gallon buckets!

Tim

x3 Shell Rotella 15-40w.

Shell is no longer making the old Shell Rotella T formula. It has recently changed the formulation and is sold under the new name "Shell Rotella T4." There is much speculation and concern that the new Rotella T4 formulation doesn't have as much zinc as the old Rotella T formula. Consequently, I switched this year to Lucas Hot Rod and Classic Car oil. It has 2100 ppm of zinc (https://lucasoil.com/pdf/Zinc_Values_MotorcycleOil.pdf).

If someone could find some actually proof or statement from Shell (not heresay) that indicates the zinc concentration has not been reduced in the new Rotella T4 formulation, I would gladly go back to using the Shell Rotella oil.

Good point Steve. I did a little research as well and neither the MSDS or Tech sheets for either T3 or T4 offer a zinc count.. All you find is heresay and supposition. The best choice is to buy a quart of T-4 and send in an oil analysis sample on it.

I read the articles that Wes referenced and gave links for a few posts back. One thing that struck me from the first article listed was:

"Some oil suppliers, believing if some ZDP was good, more would be better, added increased levels of ZDP. Unfortunately, we later learned that, with more than 0.14 percent ZDP, long-term wear increased, even though break-in wear was reduced. It was also discovered that at about 0.20 percent phosphorous, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling."

Later on the article says that for old engines that .08% is adequate but higher concentrations on break in are called for.

The article then talks about the newer formulations, ZDDP, but doesn't address the % or ppm concentrations. At least I didn't see them. This first article that I am quoting from seems to have the better overall discussion of the reasons and the recommendeihd levels. Although it is mentioned in some of the other articles that some manufac., GM, have high levels of zinc in their break in oils.

I say all this because I was struck by Cabinfevers post:

"I switched this year to Lucas Hot Rod and Classic Car oil. It has 2100 ppm of zinc "

The 2100ppm is well over the maximum recommended for ZDP. So what is the maximum amount that is recommended after break in and is that amount different for ZDP and ZDDP.

joe gibbs is another high zinc oil made for older engines