This quote is from Schneider Racing Cams:
“As many of you already know, there have been dramatic increases in flat tappet camshaft failures over the past few years. According to our research, this is due mostly to recent changes in motor oil formulas. Current strict emissions standards have pushed the oil companies to pull zinc, phosphorus, and other high-pressure lubricants (ZDDP) out of the oils. The fact that most, if not all, late model motors built after 1990 are factory equipped with roller tappet cams allowed the change. This has become so problematic for the flat tappet world that Hotrod Magazine published an article on the subject (When Good Cams Go Bad), June 2006. The life of a Flat Tappet Camshaft depends on proper lubrication. Inferior oil formulas put your camshaft and motor at risk! - - - As such we will only warrantee our camshafts when run with our accompanying valve train components and when our premium additives are used.”
Schneider Racing Cams, 1235 Cushman Ave, San Diego, Ca, 92111-0227
Phone 619-297-0227 Fax 619-297-0577 www.schneidercams.com
Schneider Racing Cams oil premium additives to solve our flat tappet problems:
Formula 1: Original camshaft lube – for initial assembly
Formula 2: Premium engine break in additive loaded with gobs of ZDDP in liquid form.
Formula 3: Mix 4 oz with any oil at oil change. Adds ZDDP plus an EP additive (Golden Ticket)
Formula 4: New. This is a fully Synthetic oil additive. To be released in 2013.
Next, I contacted DynoShop because they service many racing machines and motor homes with old flat tappet gasoline motors. I asked for the list of oils and additives that they recommend for these flat tappet motors. They do not use any additives, but all three of oils they use are synthetic multi-grade oils with high ppm of Zinc and Phosphorus (ZDDP):
- Joe Bibbs Racing 15-50
- Comp Cams # 1591 15-50
- Kendel super D (Diesel) 15-40 for lower mileage motors or colder weather trips.
Don’t forget to either add a ZDDP additive to the Onan generator oil when either adding oil, do an oil change, or use an oil with higher ppm of Zinc and Phosphorus. It also has flat tappets operating its valves. It is especially true to use the ZDDP because often the generator is not used in the winter. Adding the high ZDDP will prevent dry starts after the generator has sat for a long time. My 4 kw generator requires 4 qt per oil change so I add 4 oz of Schneider Formula 3 (ZDDP + EP additive) and then run it a short period of time to mix the oil and additive.
This also coats the flat tappets and cam to eliminate a dry start.
Don’t foget to add to add a Fuel Stabilizer to your gas tank to eliminate the problem of alcohol in gasoline sucking up the water in the air, creating a gel that will clogs filters when the gas is not used for long periods of time.
Background Information:
Early motor designs used the method of having a flat-topped cylinder riding against the cam lobe to translate the lobe’s profile to open, and a spring to close the valve. This cylinder is called a flat tappet because its contact surface is flat, freeing it to rotate and reduce wear. As higher rpms and compression ratios offered more power, valve closure springs were increased in force to enable the tappet to stay in contact with the cam lobe. This high spring load caused more contact pressure on the flat tappet and cam lobe interface creating a lot of different metallurgy solutions.
Eventually, those higher spring pressures exceeded the ability of oils to keep the two metal surfaces from wearing out. In 1941, the entry of Lubrizal’s ZDDP EP additive (zinc dialkyl dithiophosate), which coated the metal parts and allowed the two metals to slide past each other without breaking through the lubricating film. The coating also did not drain off the two surfaces when the motor was turned off. This especially proved helpful to motors that stood idle for a long time such as: fire equipment, private airplanes, RV’s, power boats, lawn mowers, snow plows, etc. All flat tappet motors built after the early‘50’s were developed with and depended on ZDDP EP additives being in the oils. Reduced ZDDP, caused by the new stricter emissions standards have pushed the oil companies to pull those catalytic converter contaminating substances out of the newer API rated oils. Without those additives, the newer formulated oils allow the flat tappets and cams to wear out faster.
By 2001, the ZDDP was reduced to 1,000 parts/million, and by 2004, when the ZDDP was reduced to 800 parts/million, cam and or flat tappet failures were produced in older motors.
Since the mid ‘90’s, all flat tappet motors have been superseded by roller lifters, or overhead cam designs, eliminating the need for ZDDP additives. The newest EPA clean air regulations are progressively taking out more of the ZDDP and EP additives. The cleanest oils with the consumer-friendly starburst insignia are the worst oils for the older GMC Motorhomes. Diesel oils, which contain ZDDP to reduce their wrist pin wear, started, as of September 2007, to reduce or even remove some of these additives to clean up their exhaust. Look out for the “cleaner” tag on these labels because they have the least amount of ZDDP and other EP additives. Since 2007, just saying that any diesel oil will do the job is no longer true.
According to both Schneider Racing Cams and DynoShop; if your coach exceeds the spec weight limit or your tow exceeds the 1,500 lb GMC Motorhome tow spec limit, you are exceeding the GMC development testing and should switch to full synthetic oils. Switching to full synthetic oil may cause increased oil leakage past old seals, requiring seal replacement.
How I Got Involved:
Three of the first 40 Coop motors remanufactured by Jasper failed within the first hours of operation. Internet searches and talks with people involved with high performance motors uncovered that this was a new failure problem throughout the flat tappet motor world. More flat tappet motor rebuilders of racing cars, boats, and motorcycles were having failures during the initial motor run-in. Since all three Coop motor failures happened on the west coast, Jim Bounds ask me to talk to the owners and installers to find out what was different about those motor’s installations and run-ins. At the same time, Jasper, under their, “warrantee to back their motors anywhere in the U.S.”, had the first failed motor removed and disassembled to find out what had happened. The flat tappet and cam had worn out within the first hours of operation.
When initial run-in failures were proven to be due to the lack of sufficient antiwear ZDDP additive, Jasper and Jim Bounds made the decision to change the Coop motor design to roller tappets. This change eliminates this problem on all new Coop motors. This also added $1,000 to the cost. All three Coop motors that failed were replaced under Jasper’s warrantee with new remanufactured motors – with roller tappets.
Jim Bounds has received a recommendation from Valvoline to use Valvoline VR 1 Racing SAE 40 oil as the best oil for his original flat tappet Coop motor remanufactured by Jasper. This oil has 1,300 PPM of zinc and 1,200 PPM of phosphorous. For older motors with flat tappets, this is one the best oils available. Valvoline does not recommend any synthetic oils nor their "Not Street Legal" oil with higher HP additives because it has less detergents, requiring a 500-mile oil change.
So far, if a motor made it through the initial flat tappet/cam-run in, they did not fail later. However, this history is based on using oils that still contained reduced amounts of ZDDP. The problem for GMC Motorhome owners is that there is no historical data of what that wear will be once the ZDDP additives are further reduced. Oils that had EP additives in sufficient quantities last year may not have them this year, or maybe the next year, and probably not in the future. Most oil labels do not indicate the amount of ZDDP, Zinc, or Phosphorous additives, so looking at the oil container is no assurance that it still has sufficient quantities for your flat tappet motor to survive in the future.
I went to my local auto parts stores to search for oil additives with ZDDP and found none there, only 2 at the NAPA store and 3 at Pep Boys.
High performance after market cam manufacturers have all solved this problem by creating, or specifying, oil additives to be used during assembly, initial break in, and adding a reduced amount at each oil change for flat tappet motors potential wear problem. That is what I learned when I talked about the problem with Schneider Racing Cams. Their recommended solution is to use half the 8 oz bottle of their existing formula 3 additive, and, in addition, to use Synthetic Royal Purple motor oil. They also told me they recommended synthetic motor oils when ever more power is produced then what was available when the motor was initially developed and tested. My Coop motor with a 3.42 differential produces 128% more torque than stock at 65-70 mph. They tested many synthetics and chose to become a Royal Purple distributor. Their facility is only 7.8 miles away from my home, so I can buy at their shop and save on shipping.
Jasper no longer rebuilds the Coop motor; Jim has it contracted out locally with the original developer, Drew Koba. You can find the data on Coop motors by going to his mechanical sub page for all the information and testing results. If you are looking into a motor replacement or a rebuild, it may be worth investigating the Coop motor as one of your options. It now offers modern roller tappets so you can use modern oils, have more power at higher rpm and a proven warrantee across the country. Miguel Mendez and Jim Kanomata can install the Coop motor here in California with other installers are being added across the nation.
It looks like the removal of antiwear ZDDP additives will answer the question that ecologists have been asking on how to get rid of those older vehicles with their dirty exhaust. In my opinion, many of these motors will eliminate themselves because those flat tappets will wear out faster. This article is an effort to delay that result for the GMC Motorhome owners who will take preventive measures. It’s just something else we have to pay attention to, to keep our older style motors running longer. ZDDP has proven it reduces friction & wear, especially at start-up, helping to eliminate dry starts. Less friction means less wear and a cooler running, longer lasting motor.
At first I tried to list some of the oils that had sufficient ZDDP to protect the GMC motors, but the oil companies are constantly changing their oils to meet new ecology and marketing demands. So, there is no way to guarantee the correct amount of ZDDP in the future, unless you add it with some aftermarket additives. I chose to stick with Schneider Racing Cams recommended solution of their formula 3 additives that will provide protection with any oil. After our first 30,000 miles on the Coop motor, DynoShop recommended switching to Royal Purple 20W-50 API SN during our HHO cell testing. That was to lower our flat tappet noise, since I always add formula 3 with ZDDP protection and we never drive our Motorhome in freezing temperatures. Freezing is the lowest temperature limit on SAE 50 weight oil.
I am no oil expert so I relied on those who work around flat tappet motors. I also have found these oil additives on the Internet where they can be ordered in quantities. Some stores have them. All these additives can be added to any motor oil:
1. Crower ZDDPPlus motor oil additive. Add a 4 oz bottled per 5 qt oil change
2. Crane Cams Superlube 8 oz bottle for break in and 4 oz (1/2 bottle) for 5 qt oil change.
3. Gum Out High Mileage (70,000 miles) 11 Oz bottle per 5 qt oil change
4. Rislone Engine oil additive with zinc ZDDP, 11 oz per 5 qt oil change for 1996 & older.
5. Schneider Racing Cams formula 3 additive, 4 oz (1/2 bottle) per 5 qt oil change.
6. STP oil Treatment. Add a 15 oz bottle per 5 qt oil change to arrive at 1,000 ppm ZDDP
7. ZDDP Plus oil additive, 4 fl oz per 5 qt oil change.
Oils that are currently acceptable for a flat tappet motor need to have Phosphorus and Zinc in the 1000-1400 parts per million ranges (ppm). The amount of ZDDP is not listed on the label and the oil manufacturer may change it to meet his current marketing needs. You should contact the manufacturer to find out which of his brands currently meet this requirement. Most of the oils are synthetics resulting in multi grade ranges for motors made before 1996 (a shrinking market).
1. Castrol Syntec Edge 5W-50 reformulated from 20-50 for classic cars. Full Synthetic with
1,300 ppm ZDDP. These can be purchased at Wal-Mart, Kmart, O’Reilly, Kragon, etc.
2. Red line Full synthetic P=1200 ppm, Z=1330 ppm “in most of their oils except diesel oils”. These can be purchased at PEP BOYS, Advanced Auto Parts, O’Reilly, and Auto Zone.
3. AMSOL SAE 20W-50 “- - with high ZDDP synthetic premium Protection designed for flat tappet motors and high continuous loads”.
4. Mobile 1 15W-50, P=1200 ppm, Z=1300 ppm synthetic, boosted for flat tappet motors
5. Valvoline VR 1 Racing SAE 40 oil non-synthetic with ZDDP for Coop flat tappet motor.
6. Oils for diesels that do not have a cleaner exhaust API starburst symbol.
7. Any of the oils used by DynoShop for older RV’s