Our older flat tappet cam engines need zinc. The SM oils have far less than the magic number of 1200 ppm zinc, which is OK for modern engines with roller cams and rockers. Also, the higher valve spring pressure rates need zinc, at least 1200 ppm. The heavy duty and diesel oils have at least 1,100 ppm of zinc, I think Shell Rotella T 15W40 dino oil is the lowest in zinc, but still above 1100 ppm. But Shell's Rotella T 5W40 synthetic oil has near 1400 zinc ppm. There are other motor oils that have plenty of zinc, but none of the SM oils do.

I'm running 10w 40 Royal Purple in a hi-po 413 RB and love it.

I think RP has one of (if not the highest) amounts of zinc in it. should be a great choice.

mnguy55,

Let me clarify the best I can. SM oils with the "star burst" label such as 0W20, 0W30, 10W30 will have far less zinc than 1,000 ppm, somewhere around 800. The heavier oils such as 10W40, 15W40, 5W50, 20W50, and others, are exempt from low levels of zinc and can exceed 800. I stay away from oils with the API Star Burst labels which is a sign that zinc is usually very limited. I also read which oils have a good amount of (at least 1200) zinc/phosphorus ppm so I know what to use and what to stay away from. Read here.
I wish I could explain why VR1 10W30 SM oil can have 1,300 zinc, but I can't. I've never concerned myself with it, so I haven't gone to the trouble to find out, nor have I heard anything about it. I have only focused on Heavy Duty engine oils.

If you want to run VR1, then run it and don't worry about the SM part.

Since I'm the person who started this thread, let me add a couple of comments...

First, I'm well aware of the implications of the reduced zinc & phos. content in the latest API ratings, which is why I specified Brad Penn Racing oil in my question. My only question was as to the applicability of the 10w30 viscosity.

That said, after reviewing other stuff outside of this arena (including my repro factory service manual), I'd say that an engine like in my RR should probably use a 10w40 or 15w40 for the conditions under which my car is usually operated. IMO, a 10w30 would be OK for a standard rebuild, or if the car was normally being operated in 50-60 degree weather. However, for example, my drive to a somewhat local car show yesterday was in mid-80 degree temps, which are common for the summer where I live, a little heavier "hot" viscosity is probably better.

FWIW, the car does currently have 15w40 in it, but I was considering running something lighter. Now I've decided it's an acceptable viscosity, even if I should choose to try a different brand.

In regards to VR1 zinc content I asked Valvoline about it today. I asked:

"Does VR1 that is currently being shipped still have the same zinc content (0.130) as this link indicates: http://www.valvoline.com/products/VR-1 Racing Motor Oil.pdf"

to which they replied:

"The Valvoline VR1 Racing Oil has never changed in the Zinc content. VR1 has always contained 1300 ppm or .130% of Zinc."

So, unless they aren’t telling the truth there is a conventional SM rated oil (VR1) that has 1300 PPM zinc.

I am going to use VR1 in my stock 1970 440HP. Hopefully it continues to run good.

I guess I need to get off the $$$ and have some VOAs done on current oil samples, such as the SM-rated VR1. I've heard enough questionable results on that stuff that there's only one way for me to have any confidence it's what Valvoline claims. Otherwise, I'd run it... but I'd make sure I put something "extra" in with it for peace of mind.

Check this out! This is Amsoil’s brand new oil, Dominator Synthetic 10W-30 Racing Oil. One of the features are “high levels of zinc and phosphorus additives make it ideal for street rods, muscle cars and other vehicles with flat-tappet cams.” It’s so new that I haven’t seen any published data or VOAs on actual zinc and phosphorus levels. Just know that if Amsoil recommends it for flat-tappet engines, there’s going to be plenty of protection for your car.

Read more…

PRODUCT DESCRIPTION
AMSOIL Dominator® Synthetic 10W-30 Racing Oil (RD30) provides superior performance and maximum protection in high-performance and racing applications. Formulated to withstand the elevated RPM, high temperatures and shock-loading common to racing applications, Dominator Synthetic 10W-30 Racing Oil delivers superior performance and maximum protection in extreme conditions. Its shear-stable formulation was engineered to provide maximum horsepower without sacrificing engine protection. Dominator Synthetic 10W-30 Racing Oil provides straight-grade protection in a multi-grade formulation.

AMSOIL, the leader in automotive synthetic lubrication, produced the world’s first API-qualified synthetic motor oil in 1972. Trust the extensive experience of AMSOIL The First in Synthetics® to do the best job protecting your engine.

MAXIMUM DURABILITY, MAXIMUM WEAR PROTECTION
AMSOIL Dominator Synthetic Racing Oil features an additive package heavily fortified with zinc and phosphorus for superior long-term wear protection. Designed for maximum durability, it ensures critical engine components are protected for the duration of the race. Dominator Synthetic Racing Oil’s superior additive technology provides unmatched durability in extreme conditions. In addition, its high levels of zinc and phosphorus additives make it ideal for street rods, muscle cars and other vehicles with flat-tappet cams.

SUPERIOR PERFORMANCE
Dominator Synthetic Racing Oil’s proprietary friction modifier provides reduced friction for maximum power and cooler engine temperatures, resulting in improved lap times and longer-lasting equipment.

PROTECTION FROM STARTUP TO THE CHECKERED FLAG
Dominator Synthetic 10W-30 Racing Oil’s multi-viscosity design provides maximum protection in temperature extremes. Dominator Racing Oil offers excellent coldstart protection and provides less drag when engine oil has not reached stable operating temperatures. It maintains superior film strength during high-temperature operation on the track.

SUPERIOR-QUALITY OILS, NO DISCRIMINATION
Many oil companies produce specialty racing oils for elite groups and do not offer them to the general public. For instance, several popular oil manufacturers produce racing oils offered only to NASCAR racers. All AMSOIL synthetic motor oils are already formulated to a higher level of performance than competitors’ oils, and AMSOIL Dominator Synthetic Racing Oil is no exception. It provides maximum performance and superior protection to all racers, regardless of their level of competition. The same AMSOIL Dominator Synthetic Racing Oil that is used in the engines of AMSOIL corporately-sponsored racers, including Scott Douglas and Brady Smith, are available to everyone.

APPLICATIONS
AMSOIL Dominator Synthetic 10W-30 Racing Oil is recommended for high-rpm, high-horsepower, turbo/supercharged, gasoline- or alcohol-burning and nitrous oxide gas-injected applications operated under severe conditions.
Applications include, but are not limited to, the following:
• Asphalt Late Model • Dirt Late Model • Modified Big Block • Modified Small Block • GM Crate Late Model • Marine • Sprint • Midget • Legend • Kart • Other domestic and import high-performance racing and street applications requiring 30-weight oil.

Purchase AMSOIL Dominator® Synthetic 10W-30 Racing Oil (RD30)



Click here to find out how you can get an immediate discount of 23% off AMSOIL Dominator Synthetic 10W-30 Racing Oil.

Why do these, oil threads, always turn into an Amsoil ads?

Brad, there are two types of VR1... One is the API SM rated, which as I understand it cannot have the 1300ppm as you already know. Published tests shown it to have somewhere around that 800ppm level. The other is VR1 that is labeled as "not legal for public highway use". That rule applies to vehicles that were required to have catalytic convertors. So you'd be fine. That's the VR1 I use for "special" cams and that stuff actually smells a little like gear lube, and looks and feels different than modern oils. It's the cam, not the whole engine. If you have a lot of spring, it will not last with any SM oil currently for sale even if the tappets rotate and the thing fires instantaneously and is broken in on the outers alone. Fast rate lobes need spring. I use 320lbs open. If you exceed that, use the VR1 offroad. If not, break it in with VR1 offroad, maybe give it a few hundred miles of seating time, then you can run a std 10-30 or thicker. IMO, one cannot use a factory rating to figure out oiling when the book was written 40 years ago and the engine is no longer using springs with 180lbs open and no lobe lift. The class of SM oils has the same protection as the earlier ratings, minus anything the EPA mandated out for additives. I wont run anything rated newer than SJ on the bottle. It's at least old stock and has the higher zink. But getting harder to find.

You post these on purpose, don't you