ACEA 3 vs. JASO MA vs. SG,SH & "flat" tappet cams

[tmcafe]

There's been debate recently about how the new oils (the ones rated SH, SJ, or even SG, SH, SJ as opposed to just SG work with flat tappet cam engines. I read in an article that ACEA 3 regulations, while aiming to meet the new emissions legislation, are also more careful to provide for enough anti-wear components in the new oils, unlike API SM, which was designed only with cars and their catalysts in mind, dropping the levels of ZDDP to such lows as to make them unsuitable for the needs of motorcycles. There's also information from Guzzi techs, for instance, who've seen recently a lot of engines with worn tappets and camshafts, and they suspect it's not just a coincidence that this problems have become more common since the dropping of the SG designation in many of the motorcycle oils (they're rated either SH,SJ, or sometimes SG,SH; the ones that say just SG are few). Any ideas?

 

[whitesands]

Really, it depends on the oil...Some SG rated oils don't exactly have alot zinc...An oil being rated SG doesn't automatically mean it's going to have any higher antiwear levels than an SH or SJ...There may be a higher limit with SG but doesn't mean it will get utilized....One example is Castrol 4T which isn't all that impressive considering it's SG rated...Interestingly, some of the new CJ-4 rated oils have higher additive levels than SG rated motorcycle oils...

 

[tmcafe]

Thanks whitesands. True, a rating doesn't mean a whole lot. I'd like to know what's in the oils, especially in terms of the additives needed for m/cycles, is there anyway to find out short of a VOA? They should disclose that stuff like on food labels, ***...

 

[wileyE]

Most those zinc-bike-cam reports only tell part of the story IMO. If it was JUST the zddp reduced than yeas maybe you could measure some wear. But if you look at the oil as whole you'll usually see other additves were also reduced. These other additive can compete with the zddp for surface, so by reducing them both the balance and wear characteristic are not compromised, at least not to the degreee the zinc watchers and MC oils marketeers would have you to believe. The reduction of the competing additives isn't really a problem either because the quality of the basestocks (in the later specs) don't require high levels. So in the end you still have a good oil with reduced zinc. Also if you look at the test sequences (including cam wear) for the newer API you'll find the bar wasn't set lower, but higher in many cases. I'd use a api-sm oil of correct grade in a bike with great confidence, but that's just me.

 

[tmcafe]

Thanks wileyE. I know that the sheer amount of ZDDP isn't the only thing by which a motorcycle oil should be judged. The problem with the new API ratings is that they were designed with the new car engines in mind. Some manufacturers acknowledge that the formulation for the new oils isn't good for some applications. I guess that's also why they make oils for older cars. Even motorcycles aren't all the same. Some have wet clutches, which have their own problem, others don't, but have other problem spots where the oil can fail to perform to the demands. I'm sure base stocks have gotten much better, so from that pov newer oils may be better.

 

[TucsonDon]

Originally Posted By: wileyE
Most those zinc-bike-cam reports only tell part of the story IMO. If it was JUST the zddp reduced than yeas maybe you could measure some wear. But if you look at the oil as whole you'll usually see other additves were also reduced. These other additive can compete with the zddp for surface, so by reducing them both the balance and wear characteristic are not compromised, at least not to the degreee the zinc watchers and MC oils marketeers would have you to believe. The reduction of the competing additives isn't really a problem either because the quality of the basestocks (in the later specs) don't require high levels. So in the end you still have a good oil with reduced zinc. Also if you look at the test sequences (including cam wear) for the newer API you'll find the bar wasn't set lower, but higher in many cases. I'd use a api-sm oil of correct grade in a bike with great confidence, but that's just me.

Very nicely argued position, wileyE ... nice job.

If raw ZDDP was the key, someone would be selling a boutique oil with 10,000ppm of the stuff. But they don't because it would be ineffective due to the out-of-balance additive pack.

I'm with you ... the SM is perfectly okay for me. I've used Rotella 15W-40 CJ-4/SM in my Goldwing and the UOAs bear out the fact it's perfectly good oil ... perhaps better than merely "good." The CJ-4/SM 5W-40 synthentic Rotella is now out, and I might well give that a shot this summer because of the heat in Tucson. Though truth be told I think the 15W-40 dino Rotella would do just as well in a water cooled bike in 110 degree heat.

 

[artificialist]

Oil companies have been inventing additives to replace ZDDP, that is why I don't worry.

 

[tmcafe]

True, but oil companies' main market isn't motorcycles. Used to be that an SG oil good for cars was good for bikes as well. Question is, SM may be good for new cars, but is it good for (all) bikes too?

In the examples above, Rotella SM/CJ is said to work fine. However, it's a heavy duty oil whose primary destination is diesels. Therefore, it may have a better additive package than a regular SM. I would use Rotella SM/CJ in a pinch, but wouldn't trust an off-the-shelf SM oil for the flat-tappet camshaft bike.

Still curious about ACEA anti-wear guidelines, said to be better than SM.

 

[Doug Hillary]

Hi,
ACEA's wear limits (A3/B3) have not changed since they were originally promulgated in 1995. These apply largely to lubricants above SAE40 viscosity

There are two (significant) limits with both ACEA and the API's SM Quality ratings
The lower HTHS limits are the key with both and they primarily apply to B1 Quality ratings and as such may not be suitable for use in engines not designed to accept them (or vice versa)

I believe that the ACEA's A1/B1 wear limits have been the same since 1995 too

HDEOs have had much more development since their introduction in the late 1930s. Anti wear ingredients are optimised in these as valve train loads are very in most of their targeted engine families

I hope this (just a simple synopsis) helps

 

[tmcafe]

Thanks Doug, this is very interesting. In the case of API, the newer designations, such as SM, are meant to update and replace the older ones, which are then eliminated, like SG was.

Since you mention both ACEA A1/B1 and A3/B3 as being issued at the same time, what is the difference between them?

 

[wileyE]

I believe A1/B1 was more about long drain interval, A3 was more about HT/HS 3.5+.

Any off the shelf 40 or 50w you'd put in a bike is going to exceed 3.5. It's the thinner car grades that you wouldn't use that you might pay attention to those specs.