CJ-4 oil for older flat tappet engines..

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Hey all... I was wondering if today's CJ-4 HDEO lubes have enough anti-wear additives to protect older engines with flat tappet cams? I know that the CJ-4 HDEO's have reduced amounts of certain additives compared to older CI-4 version. I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?
 
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Should be penty unless it has super stiff valvesprings like a 375hp 396.regular pcmo is fine for a stock engine. Theres millions of engines...jeeps,chevys etc running around on sn oil and the owner does not know a thing about oils and they are not eating cams
 
No additives are needed.

If you focus solely upon ZDDP, CJ-4 Mobil 1 Turbo Diesel Truck 5W-40 comes in at 1130ppm phosphorus, and 1250ppm zinc.

FYI, Mobil 1 15w-50 is specifically recommended for flat tappet applications -- 1200ppm phosphorus, and 1300ppm zinc.
 
Lucas oil still makes a CI4+ oil. As for the ability of CJ-4 oil to protect flat lifter cams, it seems that if you have stock cams, or cams not built for performance, CJ-4 is more than strong enough to protect those cams.
 
Thanks guys.. I believe it is a late 60's 396 motor with stiffer springs and bigger cam? He had mentioned to me also that he wasn't sure if a high viscosity oil such as 20w50 was needed or not? I did not know how to answer that..as I have no experience running older big block chevy's. I would think personally that any current 15w40 CJ-4 oil would do very well. Im not sure a HDEO 10w30 would suffice in this application? I know regarding older motors that bearing clearances and such are far larger/looser than today's engines.
 
Originally Posted By: Ponch
Are CI-4 oils even available anymore besides from Amsoil?

I would think a CJ-4 would be adequate. Nonetheless, you should still be able to find some CI-4 and CI-4+ lubes out there. Up here, it's a little hard, and Imperial Oil yanked all the old stuff. The data sheets for them still exist at XOM in the U.S. though, for what it's worth.

As you're aware, there are other choices from Amsoil, along with RP XPS and Valvoline VR1 and Defy.
 
15W-40 CJ-4 is perfect, CJ-4 having typically 1000 ppm P (phosphorus of ZDDP), 1200 ppm P being the maximum limit. They also have other antiwear additives in the mix, such as moly, which greatly increase the potency of ZDDP.

The tests for CI-4 (or CI-4 Plus) are less stringent on wear than for CJ-4, despite CI-4 (Plus) having no ZDDP limit. So, you're better off with CJ-4 than CI-4 (Plus) if you're given the choice. ZDDP is not the entire story when it comes to wear. ZDDP is necessary for wear protection but it doesn't work well in protecting against wear while used alone and the other additives can make a big difference. So, it's more the balance of ZDDP and other additives.

I would recommend Mobil Delvac 1300 Super 15W-40. If cold starts are a problem in your area (temperatures below 10 F), use a 5W-40. (For 5W-40, Rotella and Delo are cheap and Mobil 1 Turbo-Diesel Truck is also a good option.) 5W-40 is thinner (HTHS viscosity ~ 3.7 cP vs ~ 4.3 cP for 15W-40) and will wear your flat tappets more than 15W-40 but it should still be acceptable. Don't use 10W-30 CJ-4 for your flat-tappet application if you're concerned about wear. Thicker oil is better for boundary lubrication (metal-to-metal contact), such as for the lubrication of flat tappets or other wear-prone valvetrain systems.
 
If you want the answer in 30+ pages, I recommend this paper, where I went into detail about all the rumors and myths. It used to be in my signature, but I was told it doesn't meet the rules for signatures. http://www.widman.biz/Corvair/English/Links/Oil.html

The short answer in three parts is,

Yes, CI-4 or CJ-4 oils are fine. CJ-4 limits the ZDDP, and with some of the early versions, this might not have been great, but they have matured and are fine.

DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

Viscosity: Stay with the viscosity originally recommended by the manufacturer. IF it was 15W-40, I'd go to 5W-40 in most cases, especially if morning temperatures are below 50ºF. If you are going to race it high rpm's and high temp, you can go with a 5W-50. My Corvair originally called for 10W-30, which I was using, but I went to 5W-40 when I was planning on a long summer trip through an area here where normal ambient temperatures are over 120ºF, which will not do much to keep an air cooled engine in the 100º range.
 
If stiffer springs so it needs more zddp, just dope some in. You won't need a lot. Thing is, I'd do a voa before actually coming up with a treat rate to ensure that what you're doing is Ok. Don't want to dope anything too high.

Something like the redline assembly lube should do the trick. There are also zddp replacements...
 
if its a stock performance older engine.. any SN PCMO is fine after the cam has broken in. higher lift/duration cams go with a high zinc auto oil. Amsoil Zrod, Vr1.
 
My recent Schaeffer 15w40 syn blend CJ-4 had 1429 zinc, 1104 Phosphorus, 1161 Calcium, and 46 moly after 13733 miles on the oil. Haven't done a virgin analysis on it. I have been told by Schaeffer that their 5w40 full syn CJ-4 has the same add pack anti wear stuff as this one.
 
Originally Posted By: widman
DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.
 
Originally Posted By: Gokhan
Originally Posted By: widman
DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.

Also note that Non-ILSAC (non-GF-5) SN oils are exempt from the 800 ppm P ZDDP maximum limit. This means xW-40 and xW-50 SN oils have no ZDDP maximum limit. Also, high-mileage SN oils of any viscosity have no ZDDP maximum limit, as they are not GF-5. ZDDP maximum limit is imposed by the "Resource Conserving" (of the GF-5) designation, not the SN designation by itself.

This said, Mobil 1 0W-40 SN is a great alternative for flat-tappet engines. It has about 1000 ppm P (of ZDDP), which is similar to CJ-4 oils, and (probably) has trinuclear moly, the most potent kind of moly. It also has another advantage against CJ-4 oils: It's tailored more toward gasoline engines. This is unlike CJ-4 oils, which are tailored more toward diesel engines.
 
Originally Posted By: Gokhan
Also note that Non-ILSAC (non-GF-5) SN oils are exempt from the 800 ppm P ZDDP maximum limit. This means xW-40 and xW-50 SN oils have no ZDDP maximum limit. Also, high-mileage SN oils of any viscosity have no ZDDP maximum limit, as they are not GF-5. ZDDP maximum limit is imposed by the "Resource Conserving" (of the GF-5) designation, not the SN designation by itself.

The problem is, though, that just because certain viscosity or certification examples have no limitation doesn't mean they pour the stuff in. Plenty of non-ILSAC rated oils, HM examples, or pre-limitation examples had rather low zinc and phosphorous concentrations, lower, in fact, than some modern ILSAC formulations.

That's why I do like things such as most HDEOs or VR1 for such applications. At least we have confirmed, elevated additive levels.

Did I ever mention that a local WM here sells VR1 cheaper than normal PCMO?
wink.gif
 
Most of the current crop of HDEOs have MORE ZDDP than the PCMO oils from back in the day. If you go to Blackstone Lab's website and find the newsletters from 2012, you will see a batch of vintage oil VOAs. They tested unused oils as old as the 1930s and 1940s. If you look at the more recent oils from the '60s and '70s, you will find some with very little ZDDP and some with very moderate amounts under 1000 ppm. A few showed on 100-300 ppm. A few are as high as 1200 ppm. I have posted some VOAs from the late '80s and they were around 1000 ppm. In many cases even the current PCMO has enough zinc for low performance flat-tappet applications that aren't breaking in a new cam. I think one is prudent to want a bit more ZDDP than 800 ppm and HDEOs are but one alternative. You might look at the QS Defy line as well. The HDEOs are a good choice but the viscosity choices are more limited.
 
I would go with Mobil 1 0W-40 SN -- 1000 ppm P. Get a 5 qt jug from Walmart.

Here is the table of Mobil 1 oils (PDF file), showing their ZDDP levels. Some go up to 1750 ppm P, well above the CJ-4 maximum limit. GF-5 minimum and maximum limits are 600 - 800 ppm P. CJ-4 minimum and maximum limits are 0 - 1200 ppm P (no minimum limit). Also note that the type of ZDDP used in diesel-engine oil is more an antioxidant than an antiwear additive. This is in contrast to gasoline-engine oils, where the type of ZDDP used is more an antiwear than an antioxidant additive.

Here is the Q&A from the Mobil 1 Web site:

Question:
Mixing Motor Oil to Reach the Right ZDDP Level for Classic Cars
For an older, flat tappet, performance motor with inherent cam wear issues is there any benefit to mixing high ZDDP Mobil 1 Racing 4T 10W-40 to Mobil 1 High Mileage 0W-30 oil? The 15W-50 creates TOO MUCH oil pressure. It would be nice if you had a product for 'Classic' cars, high ZDDP, 0W-30 and 0W-40. I have used nothing but Mobil 1 for 15+ years.
-- Bill McCauley, Tallmadge, OH

Answer:
Mobil 1 0W-40 already contains a higher level of ZDDP (1000 ppm) that could benefit your flat tappet engine. We also have a Mobil 1 High Mileage 10W-40 (1000 ppm); see our table listing the phosphorous levels for all Mobil 1 synthetic motor oils.
 
Originally Posted By: Gokhan
Also note that the type of ZDDP used in diesel-engine oil is more an antioxidant than an antiwear additive. This is in contrast to gasoline-engine oils, where the type of ZDDP used is more an antiwear than an antioxidant additive.

The following is a good read on why you shouldn't use diesel-engine oils in flat-tappet gasoline engines:

Why NOT diesel or racing oil? (link from Cam-Shield oil treatment)

Contrary to the current internet buzz that diesel oil is the oil to use in a gasoline flat tappet cam engine, the correct oil to use on a continuous basis in your classic car's flat tappet cam engine is an oil designed for gasoline engines that contains the correct level of ZDDP anti-wear protection. Similarly, a race oil is not recommended for continued use in a street driven gasoline engine.

If you look on the back of a bottle of oil you will see the API performance classification for the oil. Diesel oils with API credentials of CI-4, CI-4 Plus, CJ-4 will typically have Zinc levels around 1100 parts per million (ppm). For a flat tappet cam gasoline engine with moderate valve spring pressures (such as a flat head engine) the generally accepted minimum level of protection is 1200 to 1300 ppm of Zinc. For muscle cars and hot rods with higher valve spring pressures, 1600 ppm will give uncompromised protection. Race cars generally need around 2000 ppm. Break-in of a new cam is generally best protected with around 2500 ppm (in addition to the molybdenum cam lobe lube). Current API SM/ILSAC GF-4 gasoline engine oils have incredible performance capabilities and will have approximately 850 ppm of Zinc, but will need to be supplemented with ZDDP to make them suitable for use in flat tappet cam engines in classic cars, hot rods and race cars. It is extremely important to add a highly concentrated ZDDP product so as not to dilute the oil and thus impact the performance integrity of the engine oil.

Here are the differences between diesel engine oil and gasoline engine oil. In a modern diesel engine there is substantial exhaust soot contamination that the engine oil must contend with. Diesel oil is designed with much higher levels of detergency and dispersency to fight the soot contamination. Like ZDDP anti-wear chemistry, detergents are a surface active chemistry and compete directly for space on metal surfaces, such as the cam lobe and lifter face. So, in practice, the effective level of Zinc anti-wear is a bit lower than what we expect it to be based solely on chemical analysis. Additionally, the ZDDP that is generally used in diesel formulas is primary ZDDP (which activates at higher engine temperatures) since a diesel engine runs predominantly at operating temperature. In a gasoline engine, we must have both primary and secondary ZDDP (which activates at lower temperatures) since the engine will experience a significant number of cold starts. Also, the viscosity modifier polymers that are used in multi-viscosity engine oil to prevent viscosity loss at operating temperature (to protect the bearings) are different for diesel oil and gasoline oil. Diesels operate at essentially the same rpm all day long and need polymers that are shear stable to protect the bearings. Gasoline engines experience many large ranges of rpm during operation and require polymers that have both shear stability and thickening efficiency capability to protect the bearings.

Race oil formulas are typically designed with reduced levels of detergency and dispersency to improve performance of the anti-wear and friction modifier chemistries. Race oil is typically changed very frequently and race engines are typically re-built frequently. For a street driven gasoline engine, the correct levels of detergency and dispersency are required to prevent deposit formation (particularly at the piston rings), and sludge formation, from contaminants. This becomes more important to classic car owners who may only drive the vehicle occasionally and who change the oil once or twice a year.
 
Originally Posted By: Gokhan
For a flat tappet cam gasoline engine with moderate valve spring pressures (such as a flat head engine) the generally accepted minimum level of protection is 1200 to 1300 ppm of Zinc.


Generally accepted by whom? The companies that make specialty oils for "classic" cars and want to steer you away from other, less expensive oils? Or is it from companies that sell ZDDP additives that want to scare us into more ZDDP? Actually, I see you clipped the sales pitch from the Cam-Shield website in your post, in addition to linking to it, and that is not your own writing. I would hardly regard that as an objective source of information.

The less complex truth is the API has backrated many SM and SN oils for flat tappet engines. That may or may not be the whole story, but testing was done to qualify the ratings based on the 800 ppm levels of ZDDP. And remember that their are other additives that do the same thing. I personally think nearer 1000 should be a minimum, no other additives in the picture.

One good clarification point: A purely "diesel rated" oil, e.g. API CI only, is not suitable for any gas engine. That has less to do with ZDDP than other things, however. But when we talk about HDEOs, we are talking about dual rated oils that may be CJ-4/SM or CI-4/SM. They are dual rated for gas or diesel and contain enough for diesels and way more than a low-po flat tappet engine requires unless breaking in a new cam.

FInally, if 1300 is the minimum amount required, how do you account for the fact that many older oils, period to the era of the flat tappet, had nowhere near that much?
 
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