Modern Oils for Our Flat Tappet Engines

[Bob_Spidell]

So, the typical cam break-in procedure-this one is from Crane's instructions--which always state 'Do not use API rated “SL” or “SM” oil' is misleading or are they possibly referring to lower viscosity oils (typically used in break-in)?

 

[Michael Oritt]

I believe 1200 ppm is considered about the minimum acceptable amount of zinc.
Why play tag with destroying your camshaft?

 

[RAC68]

Hi All,

We have been talking about oil additive packages and in most cases we must take the levels required and description of benefits on faith, the statements of more knowledgeable Forum members, and product promotions. I accept that ZDDP is good for my flat tappet engine and must also accept that the general 1100 - 1400 PPMs is the required level. As I see it, Michael is right on and I accept the 1200 +/- 100 PPMs for ZDDP but,

What other engine oil component are critical to have and in what levels?
What engine oil components are NOT Desirable to have?
How would you easily find out? At no additional cost?

At this point, and with my very limited knowledge in metallurgy or oil chemistry, I accept the recommendation of more knowledgeable Forum members and the honesty of oil producers to want to fully address the requirements of our classic engines. In that approach, I have come to accepted Mobile 1 15W50 synthetic with all its components and additives and had previously done the same when using VR1 20W50.

Ray(64BJ8P1)

 

[twas_brillig]

Recently I got into a discussion regards oil and old VW Beetle air cooled engines with a retailer who'd been advised by a mechanic/buddy that Rotella had decreased their ZDDP levels. This may have happened, but their levels currently are still just tickety-boo for our engines.
I wrote Shell and Castrol for their recommendations, and here are the replies (and the Castrol response is a good one that encompasses the whole issue). I'm sure that the others previously discussed are still doing fine, but these are the two that I checked with. Doug

***************************************************************************************************************************************************************
From Shell:

Case No: 00372936
Enquiry: Shell Rotella for old, flat tappet, engines?
Response:

Hello James,

Trust you are well. For vehicles requiring high ZDDP oil, you may use our Rotella T4 15W-40. This has approximately 1200 ppm of zinc and 1100 ppm of phosphorus which should provide adequate protection to older flat tappet cams.

Hope this helps. Stay safe

*********************************************************************************************************************************************************
From Castrol:

Thank you for contacting Castrol North America.

Classic cars with flat tappet cam engines represent a special case regarding engine oil lubrication. These engines have valve train configurations that require elevated levels of ZDDP (zinc dialkyl dithiophosphate) anti-wear for proper protection of the flat tappet camshaft and its lifters. Insufficient concentration of ZDDP will lead to premature wear and failure of the camshaft and lifters. Current ILSAC GF-5 and GF-6 fuel economy grade engine oils are designed for the extended life of the catalytic convertors in modern passenger cars and have industry-mandated limitations on the amount of sulfur and phosphorus within the oil.

The following Castrol oil is blended with a high zinc and phosphorus content to help prevent premature aging, wear, and metal fatigue on engines with high-tension valve springs or performance modifications that create high contact pressure and extreme internal temperatures (i.e., push-rod, flat tappet engines, and performance cam applications):

• Castrol EDGE 5W-50 (Full Synthetic Oil Formula)
Features/Benefits
High Zinc – Typical Level 1300 ppm
Excellent cold temperature properties
High-temperature viscosity (SAE 50) that is suitable for use in many classic car applications

Castrol GTX Classic 20W-50 is expected to become available for purchase in Canada at some point in 2023.

• Castrol GTX Classic 20W-50 (Conventional Oil Formula)
Features/Benefits:
High Zinc (1400 ppm max)
Specially formulated to provide unsurpassed wear protection for classic/collector cars & racing applications
Compatible with gasoline and alcohol-based fuels
Available exclusively through Wal-Mart

Castrol always recommends following the guidelines of the engine manufacturer for the recommended oil (i.e., SAE grade, API rating, and manufacturer specifications) specific to your application, and/or please consult your mechanic/engine rebuilder as to the suitability of the 20W-50 or 5W-50 viscosity grade in your engine.

Thank you again for contacting Castrol, we value your patronage!

Castrol Consumer Relations
1-800-462-0835
Hours of Operation: Monday - Friday 9:00 am - 7:00 pm EST

 

[NutmegCT]

Thanks for posting their responses. This has been an on-going question for years. Good to read some relatively "official" comments from the manufacturers.
Tom M.

 

[Legal Bill]

I’d like to hear from people who are actually using, or have tried, the Castrol Edge 5W-50. Specifically, did you notice any change in oil pressure (hot, cold, idle or at speed)? Also, did you notice any increase in oil leaks?

 

[Editor_Reid]

Allow me to add one more manufacturer's response.

Several years ago a mechanic working on my 1974 Porsche 914 2.0 did an oil change, among other things. He used "Brad Penn" brand oil in 20w50. It is a semi-synthetic oil. The car felt like the engine was revving more freely, and I liked the idea of a semi-synthetic for the already very-broken in engines in my old cars. I bought a couple of cases of it and have used it since with no issues.

Some time ago they changed the brand name to "Penn Grade" and in a discussion with a couple of friends about oil choices for old cars I went ahead and asked Penn Grade for some specifics on the ZDDP and phosphorous content of their oil. Here is their response from just two months ago:

Thank you for contacting D-A / Penn Grade / PennGrade1 Lubricants and for your inquiry.

Our PennGrade1® Partial Synthetic High Performance Oil SAE 20W-50 (#71196) possesses a typical 1500 PPM (Parts Per Million) of Zinc, 1400 PPM of Phosphorous. The aforementioned constitutes the enhanced AW (antiwear) package of the product. See attached typical properties on page (2). [If you'd like a copy of those specs, email me at editor@healeyclub.org and I'll send you their info sheet by return email.]

Reid......I can certainly understand why you are asking........since today’s engine oil formulations contain a drastically reduced level of antiwear.....all done to protect and extend the life of the catalytic converter. As I’m sure you are aware, antiwear additives are especially important in protecting the flat tappet (or roller cam) an engine employs. Unfortunately, higher levels of AW chemistry (specifically Phosphorous) can be detrimental to sensitive emission systems like catalytic converter or O2 sensor. If your system does not have said catalytic converter OR O2 sensor......it would be permittable (and necessary) to use higher ZDDP laden engine oil. PennGrade1 Partial Synthetic High Performance Oils are unlicensed engine oils for one reason.....enhanced ZDDP. We simply did not want to be guidelined by the amount of antiwear we incorporated into the PennGrade1 formulations. Classic, vintage, legacy, historic, muscle car, street rod and high performance engine owners utilize PennGrade1 for simply one reason.....unparalleled component protection.

Hope this information helps Reid.....but feel free to contact me direct should you wish to discuss further.

Kenneth M. (Ken) Tyger, OMA II, OMA I
National Director
Gas Recovery Systems
PennGrade1 Consultant

This oil is not easy to find, but I order it on Amazon. Note that it may still be listed and labeled there as Brad Penn brand, but it's the same stuff. And by the way, if it has increased the leakage of these engines, I have not noticed it. I have arrived at a point in life where I am at peace with oil leaks in these old cars. You can spend your remaining days and your fortune trying to eliminate oil leaks, or you can spend your remaining days driving these old cars. I've made my choice.