Modern oils bad for flat tappet camshafts

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I've been using a full synthetic HDEO (Esso XD-3 0W-40) in my 2 Jeeps' "flat lifter" type engines for a couple of years now.My emission tests have read lower while using this type of oil and after reading this article I would use HDEO's as a regular oil change oil,not just a break-in oil.
So, are you guys on the "SM oils will kill a flat tappet cam" bandwagon?

The guys over on the Ford Truck Enthusiasts forum definitely are.
One more thread playing to the panic-prone that if ya' yell "Fire!" loudly enough and long enough, people will panic. Obviously it works on BITOG despite evidence to the contrary in the UOA section. I can already see the next post: "Don't confuse us with the facts, Ray - our minds are already made up because some company pushing its high-profit snake oil says that SM oils are for crap." (Oh, lest we forget, "imported lifters" are junk, too. Look at all the Honda camshafts that grind down to oblivion daily because of their inferior lifters.
) What a laugh - some people deserve to be parted from their money.
got the worst iron reading of all 6 of my oil samples taken with the 'SM' rated M1 sample being used in my flat tappet(non-roller) 98 Suzuki Swift 1.3L motor. 5 of them were 10,000 mile run samples--IRON results were: Amsoil 10/GC 28/M1 "SL" 28 & 47 than made a run with M1 "SM" and it had a 59. The last run(#6) was run 15,000 miles with M1 EP "SL" and it only had a iron reading of 24. Will not be running anymore 'SM' here. Traded all my M1 'SM' bought with the "buy3-get3 free" Pep Boys coupons for 0/5w30 'SL' M1 which helped all my local NAPA dealers get rid of their old 'SL' rated M1 stock. This motor has 4valves per cyl being run off a single(1)overhead cam-- Flat tappet with NO rollers. Until I buy something newer with rollers I'll stay with the extra zinc(have a second 01 Swift waiting in the wing for the wear out of this 98, so it maybe awhile--a big while if these two go the distance my 96 did being it's still running with almost 300,000 on it!!)
I plan on working off of my stockpile of SL Rotella Syn and SL Mobil 1 Truck and SUV, plus some Castrol Tection and Delvac 1300.

I think I will pass on SM offerings for now.
If one reads that article carefully, it's the break-in procedure that is most critical to insure long life of a flat tappet camshaft and associated lifter. This exactly mirrors what the developers of SM/GF-4 standard found. To allay fears of premature camshaft wear they redesigned the Sequence IIIG test engine to use flat tappet camshaft, associated lifter and valve-train components to mimic an early 80's style engine and specified a fairly brutal test with specific limits in relation to valve-train wear among others parameters. This is an OHV pushrod engine with a lot more mass in the valve-train than an OHC engine with finger followers or bucket lifters under the cam. So confident are the developers of the SM/GF-4 specification that one GM engineer noted that "If an oil passes the IIIG it will protect any GM car, whether it has slider followers or roller followers. Doesn’t matter."

Now keep in mind that an engine with flat tappet camshaft(s) and associated lifters, pushrods, etc, will deplete the ZDDP substantially faster than an equivalent engine equipped with roller design components, so one has to be careful with extended OCIs. It may be prudent to use the OEM original OCI recommendations as a guide and then incrementally increase the interval until you see signs of additional wear. I would recommend you do the same even if you choose an oil with more AW additives than the SM/GF-4 level and/or you add AW supplements. Additionally, the posted UOAs, matched to your engine, may also be used as a guide.

Finally, if you got a high-dollar custom built engine, there always professional services like Terry's. Cheap insurance in my book.

[ February 26, 2006, 02:35 PM: Message edited by: 427Z06 ]
Maybe the answer is to use M1 EP 5w-30, as it has much more SuperSyn added than "regular" M1. The SuperSyn gets credit for maintaining the oil film better.
I dunno what to believe???
If I had a 427 COPO Camaro with a high lift cam, I'd likely not use SM/GF-4 oil. But your run of the mill street engine with non-roller cam followers? SM/GF-4 is likely to provide all the protection you'll need. The zinc and phosphorus amounts in GF-4 oils are not that much lower than the later years of SL. If oils routinely showed up with 300 ppm ZDDP, I'd be concerned! But SM oils are practically at SL amounts, and the base oils are better to boot. Why worry? Oh, this is BITOG
Ray H, the reference to imported valve lifters is NOT referring to the OEM Import Lifters, but to the multitude of "off shore" or "Asian sourced" valve lifters that are pretty much everywhere in the automotive replacement parts supply chains. These lifters do not carry USA OEM name brands as such, but are usually available from auto supply and machine shop sources. Just as with other aftermarket parts from those regions, there are good ones and less-good ones -- which you don't know when you buy them as "they all look the same" outside of the materials used in their packaging.

If the parts have an OEM manufacturer or (OEM or USA name brand) aftermarket vendor's name on the packaging, those parts are made to the seller's specific specifications and quality/durability standards. Otherwise, items sourced from those regions can vary from one name on the box to another name on the box.

It's the inconsistent quality issue that has prompted some camshaft manufactuers to make the statements they have, which some has interpreted to be "bashing" in nature. From the perspective of the camshaft manufacturers, THEY have to protect their good name and do not desire it to be downgraded if a customer decides to buy some auto supply lifters (of undertermined quality) rather than their more expensive "matching" lifters with the camshaft. I suspect the cam manufacturers have done enough R&D with their camshafts and replacement lifters to know what really works and what does not.

On the subject of the GM Engine Oil Supplement, which many cam manufactuers recommend, possibly in conjunction with their own "moly" lube paste . . . there used to be TWO forms of GM EOS. One is the "small bottle" supplement that is currently available (highly viscous) and the other one is the "one quart of oil replacement" that was formerly available.

Both tended to have the same dialogue on the container, but were used in different manners. GM now has a "Camshaft and Lifter Prelube", which seems to mimick what the aftermarket camshaft makers have offered for years (at least in size and orientation of the packaging).

I went into PepBoys a while back and read oil bottles for notations of "ZDDP". Some specific Valvoline and Castrol products have these notations on the back of the container. Certain Valvoline VR1 "off road use" racing oils and motorcycle oils, plus the Castrol Tection 15W40 oils, but not on the GTX Diesel 15W40 bottles (obviously for lighter duty diesels). A mixed bag of sorts, but still "options". Considering that ZDDP is what it is, I suspect the marketing operatives will note its presence in the product (seizing the moment, so to speak) for the more informed consumer.

To me, the really big question would be what is replacing the small amount of zinc that has been removed? Some manufacturer's website charts list the % of zinc and such in them. Surely, the oil companies know that these products will be or can be used in flat tappet engines rather than exclusively in roller cam motors?

Just some thoughts,
Mobil 1 EP should still be rated SL also so it should have the higher amounts of zinc and phosphorous. I'm not taking any chances for now. I'm using VSOT with SM oils.
Consider also that some of the SL oils supposedly were coming with SM levels of zddp as we moved closer to SM. I'm not sure you can add enough zddp with VSOT, being it is so thick. I think zddp should be around 1200 ppm.
I'd like to see how an API SM oil does in the VW T4 test, which evaluates:

- piston rings (sticking)
- piston cleanliness
- cylinders, cam lobes, cam followers and seals containing elastomer materials

During the 248-hour oil test, these are evaluated:

- kinematic viscosity
- iron content
- chrome content
- copper content

Pass/fail criteria are:

- absolute viscosity
- viscosity increase
- TBN depletion
- piston cleanliness
Consider also that some of the aftermarket cams aren't that great either. It's ez for them to blame the lifter or the oil used. Also the engine builder/tuner can wipe the cam the 1st minute of run time if he's a hacker. Also past a certain rpm the zddp isn't really that big a player anyway, the oil film is.

Most engines that spec SM/GF-4 oils aren't as finicky as those VW/Audi engines.

Isn't the ACEA C3 spec similar to API SM, both specs being low SAPS? VW claims backwards compatibility of VW 504/507 in even ACEA A3/B4 applications.

Cam someone elaborate on the wear limits allowed by API SM?

- average cam plus lifter wear: max 60 microns
- cam wear average: max 90 microns
- bearing weight loss: max 26 mg
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