Asking for proof my API SM or SN oil is bad

[NH73]

I have heard about the whole ZDDP levels being dropped in todays oil and people claiming it is not good for lawn mower engines. I also understand that the oil ratings are backwards compatible, and there is some substitute anti-wear additive to offset the difference. But there are people here claiming the higher the ZDDP level the better. I like to see proof that the API is wrong in saying they are backwards compatible. I like to know why the higher the ZDDP level the better and what ever SN oil is will be bad for my lawn mower engine.

 

[Brybo86]

it depends on what your lawn mower engine calls for.

If you are looking for a current SL I think VR1 10w30 is SL ... ?

I think the SN is perfectly fine for you OPE engines

 

[Quest]

lawn mower engines cams are such low-stressed type (remember: B&S and Honda OPE engines typically used a nylon (plastic) cam design to drive the valves), typically, ZDDP level doesn't even matter in most of these cases.

Why fuss over ZDDP level? (ZDDP) is not the only game in town!

Q.

 

[Yah-Tah-Hey]

There is a point where too much zinc can cause problems. I wouldn't spend much time worrying about your lawn mower engine. Change the oil every twenty five hours, replace the air filter frequently,assure good cooling air flow and your lawn mower will last many years. Any well know brand of oil in the correct viscosity(probably 30) will be more than adequate. That is not a difficult application. In fact, it is probably one of the easiest.You can purchase ZDDP from Eastwood and others if the conundrum will keep you up at night. Regards

 

[old1]

As others have said, the zddp is not that important in ope. Even in old motor vehicles with stock non high performance engines the modern oils are ok, although I do like a little more in my classics, I have been using modern oils in my, and my customers ope forever, with no problems. As was stated previously, the spring pressure in small engines is so light (I can compress most of them with my fingers) that most any oil is fine.

 

[Danh]

As others have said, it probably doesn't matter. But if you're concerned, use Quaker State Defy or Mobil1 High Mileage: both are SL-rated and have more zinc and phosphorous than SN allows.

 

[Brian Barnhart]

I find it interesting that at least a few of the small engine manufacturers that market their own oil offer non-starburst 10W30 or SAE30 SJ or SL oils.

Briggs and Stratton’s oil offering is SJ, but they do say the newer energy/resource conserving oils are acceptable in some cases (10W30). They also state that conventional 10W30 may increase oil consumption when used above 80F. Conventional 5W30 is only recommended at temperatures below 40F, and SAE30 is recommended only above 40F (due to increased starting difficulty below that temp). Synthetic 5W30 is recommended for any temp.

So, in the case of B&S, they market SJ oil and offer a variety of limited recommendations of various 30 weight oils. So their product offering and recommendations are different than the 5W20 or 5W30 energy conserving oil for all conditions that is common in the automotive market today.

I offer no “proof”. Nor am I even saying that ZDDP levels are a concern.

One wonders if the small engine manufacturers are involved at all in the API requirements.

Consider their recommendations, draw your own conclusions, and make your oil choice.

 

[OneEyeJack]

Clean oil of the correct viscosity is about all you have to worry about for lubrication.

You should also keep the external parts of an air cooled engine clean. Also keep that air filter clean, too.

I'm retiring a Sears Eager 1 from 1980 because the chassis is rotting away and the wheels keep falling off. The engine still runs well and does not smoke. I think I contributed to the rot by hosing the mower down after use, before putting it away. Part of this time was in Katy, Texas and because of the heat and humidity the grass needed to be cut sometimes twice a week and it was a job keeping the export chute clear. In those days that mower worked hard for its living.

 

[Boomer]

I wouldn't be surprised to find that these "special" 30W oils for small engines are just rebottled Rotella straight 30W. This used to be SJ but they no longer put that on the bottle as it is not supported by API.

 

[Quest]

OPE engines are not different in fundamental designs and operations like ordinary gasoline Normally Aspirated spark-ignition engines.

So, what goes and works well in automotive gasoline engines will work just as well in OPE engines.

In the case of B&S flathead engines, the design (flathead, with side valves) is so old, it dates back to Ford model-T era. It's low compression (less than 7.3:1 compression ratio) and the rest of the designs in pistons, rings, etc. are the same as automotive engines of yore, it just means that automobile oils will definitely work on them.

Just because B&S and the likes does not have the kind of additional R&D money to devote into lubricant (and they would re-use/refer to older or other lubricant specifications as their form of reference to use in their OPE engines), meaning that they would simply recycle materials from some 30+yrs ago or even older, just because it "works" before.

Think of it this way: modern NA gasoline engines are on API SN grade already, with much higher compression, OHC, high revv, etc. and yet they can still last hundreds of thousands of miles using this "reduced ZDDP" oil grade, in that sense, you think your engine would be drastically shorted it's service life with those low compression, low valve spring pressure, plastic cam type OPE engines just because of the reduced ZDDP contents?

Mind you though: ZDDP doesn't "adhere" onto plastic cam lobes.

The only concern on OPE engines are typically air-cooled, and will require a slightly thicker oil viscosity type to keep it from "boiling off".

Just use whatever your heart's content, and never lose sleep over the additives part.

Q.

 

[Quest]

oh and BTW: most OPE engines of flathead type doesn't even come with valve stem seal to begin with, so a bit of oil consumption through valve guides is deemed normal.

So much for the archaic engine designs and the concerns most posters have.... (*laughs*)

Q.

 

[bubbatime]

What engine so we can offer better, more specific advice?

 

[NH73]

I have a Kawasaki FR-730V. On a Zero-turn mower. The reason I ask is because I see people on here are bent on not using a SM and SN oil because of there reduced ZDDP levels. I not interested in spending big bucks on lubricates, just name brand synthetic oils I can find at a good deal.

 

[mrsilv04]

This is all you really need... and rest easy.

 

[AMC]

Originally Posted By: mrsilv04
This is all you really need... and rest easy.

That is exactly what I was going to say. The new Delo 400 LE 10w-30 is great too! Heavy duty diesel oils are loaded with good additives.

 

[HerrStig]

THe BMW classic bike sites have plenty of info on the "flat tappet" syndrome. Boxer motors are built like farm implements but DO need some zinc because of the flat tappets. You'll probably read more about zinc and flat tappets there than you want to know. To cut to the chase, lots of riders use T6 in 5/40. I now use the same grade in my 25 year old Briggs generator as well, burns NONE, and started at FOUR degrees several years ago with one pull. The old Briggs engines are splash lubricated which shears oil, I am told, and of course run HOT when it's hot outside.

 

[fdcg27]

What engine?
The old flatheads really won't care what spec or grade you put in them as long as they have oil.
With some of the newer designs, it might make some difference.

 

[Clevy]

Originally Posted By: Quest
lawn mower engines cams are such low-stressed type (remember: B&S and Honda OPE engines typically used a nylon (plastic) cam design to drive the valves), typically, ZDDP level doesn't even matter in most of these cases.

Why fuss over ZDDP level? (ZDDP) is not the only game in town!

Q.



Well put.

Today's oils aren't what they once were. We've got high tech additives and the oil companies spend huge money developing new products. Zddp is definitely not the only anti-wear game in town.

 

[Brian Barnhart]

There are other factors that should be considered when choosing an oil for a small engines.

Though mildly tuned in most cases, small engines often operate at a high percentage of their rated output. The typical auto spends very little time producing more than 20% of it’s rated output. Small engines often spend much of their operating time producing more than 50% of their rated output.

My small generator in particular frequently sees extended high loads, and runs WOT when powering my electric water heater. When cutting high grass or mulching leaves in the fall, the 27HP twin on my mower operates at very high load, and sometimes I need to slow down to keep the deck speed high. So the typical operating conditions of some small engines may be more like tracking a car than driving it to work.

Many small engines are air cooled. As a result, their operating temperatures are not as well controlled as those with liquid cooling and thermostats. To allow for greater variations in operating conditions, engine clearances may be greater under some operating conditions than those found in liquid cooled engines.

Many small engines do not have pressure lubrication. Not sure how that might matter (if at all), but it does distinguish them from the typical automobile engine.

Many manufacturers of small engines recommend changing the oil between 25 and 50 hours of operation. The would be the equivalent to only one or two thousand miles in a automobile. The more frequent OCI recommendation may be related to the differences in engine design and operating conditions described above.

I’m not trying to argue that additional ZDDP is needed in these engines. But just because the latest oils are great for your car doesn’t mean that those same oils are great for your small engine. Just like any other application, match the oil to the engine’s needs.

 

[bubbatime]

Run any diesel spec 15W40 conventional, or if you must have synthetic, a diesel 5W40 oil.