What are you using in flat tappet engines? I was using Rotella, but I understand they reduced the zinc.

 

Lucas Hot Rod and classic is all i use in flat tappet stuff it has 2100 ppm zinc ive run over 300 lbs on the springs with no problems.

i do not use it for break in though, i use a break in oil like the lucas with SAE 30 with 3,634 PPM or amzoil SAE 30

never had a flat tappet go bad

 

Valvoline VR1 10w30.

 

Amsoil Z-Rod 10W-30.

 

Thanks

 

Add me to the list of Lucas fans.

 

I use Rotella T4 15W40 in my 71 and 96 Olds; as well as, my 86 Ford F250. I haven't heard anything about them reformulating the oil.

 

I have heard that about Shell Rotella but have no idea if it is true or not. I used the Valvoline VR1 Racing Oil in my 54 but use 20W50 since it is an old engine and seems to have a bigger appetite for the 10W30.

 

Mobil 1 20W50 Full Synthetic has 1300 ppm Zinc, and 1200 ppm Phosphorus. My '67 400ci loves it.

 

Why 20W50?

 

Yes, new Diesel oil has a reduced amount the amount of ZDDP. It is necessary, along with high detergents for emissions. Like Catalytic Converters, it plugs particulate filters. New Diesels constantly break down, a PITA. For a stock peanut cam motor with 50 year old springs, you can probably get away with SP oil, so Rotella with 1000+ PPM ZDDP, you are going to be fine.

 

I like the added protection of a heavier weight oil in the hot St. Louis summers. Mid-June through August I can count on +90° to over 100°. This particular blend of Mobil 1, per the Mobil 1 Spec Guide, is specially designed for flat tappet and/or High Temp/High Stress conditions.

 

10W-30 should be plenty of protection. Maybe 10W-40 in extreme cases. 20W-50 is for race engines with loose tolerances or worn out ones and will actually accelerate wear when running cold.