STP at oil change?

[mfg]

I hear much negative news about modern oils being detrimental to flat tappet cams… I’ve never tried the ZDDP additive.. but do faithfully add a pint of STP to my collector car engines when I change oil … So far so good (I hope!)

[DWR46]

STP does have some ZDDP, but not a lot. My personal view is to use either Valvoline VR1, or Castrol Classic oil. Either one has levels of ZDDP that will protect American pushrod engines. What STP will do is add viscosity. It is useful in engines that need a "thicker" oil due to bearing wear. STP does "cling" to surfaces and helps parts stay lubricated when the engine is not run for a while.

[aardvark]

I've heard arguments from all sides, but what made the best sense is these Oil Mfgr's have done all the science and chemistry that  we as Pikers just don't even have a clue to.

STP changes the entire chemistry and viscosity of what the Oil Co has designed and is a crap shoot to much with that. So me personally, I've gone Castrol Synthetics on everything I drive.  On V-8's I'm getting 250-350k miles on my daily drivers. One went over the 350k mark. I sold it, and I saw it on the road some 2 years later.

Do as You wish, but realize these Oil Mfgr's are pulling out all stops for engine longevity...Wanna mess with the mix... Not Me!

[wildfelr]

RQB3263/81/305  HERE IS MY CHOICE AS 3263 PUSHING 150,000 MILES  .. NO STP NEEDED HERE JUST HIGH QUALITY DIESEL OIL AND ZZZP ADDITIVE EVERY 3000 OR SO MILES ....GOOD LUCK

[wildfelr]

ZDDP AVAILABLE ON AMAZON ABOUT $7.00 FOR 4 OZ .......BTW... I ADD IT TO ALL MY IC ENGINES... DIESEL LAWN MOWERS , RAM HEMI TRK, JD GATOR, LYCOMING  AIRCRAFT ENGINE, YOU  WILL NEED TO BUY 24 COUNT TO GET IT AT THAT PRICE...THATS THE BEST PRICE I HAVE FOUND ...

GOOD LUCK ...WILDFELR

[aardvark]

Wild... the Shell brand is scientifically blended by Shells Scientists, thus they likely can be trusted... Good Choice.

BUT...I have to ask.. If ZDDP is such an ''engine savior'' why then isn't it in ALL Motor Oils?

After all, all Oil Companies have a stake in long life engine data. That's why Synthetics have become popular...Longevity.

My F-150 now has 300k miles and doesn't smoke or burn oil except the acceptable amount of a 1/2 quart per 5000 miles on standard Castrol Synth.                                       same with my Hummer H2 at 175k miles...And this is not unusual for my vehicles. I change oil every 10-12k ish miles..The advent of synthetics either as a 1/2 1/2 mix or full synth has changed the necessity of oil changes every 3000ish miles. I held to that 3000 mile parameter for decades and then 15 years ago (about 10 years after Mobil1 was introduced) I followed the science and converted my F-150 over slowly to full synth (after 3ish oil changes with a 50/50 mix.)..  I'll hold to not messing with an Oil Companies research and chemistry balance. Their Scientists are of a better pay grade  than '''any of us''' at deciding what is and is not good in the mix.

These discussions are commonplace on ''most any'' Vehicle Forum and everyone comes at their decisions from a different angle.  My angle is ''Multiple Vehicles'' running well past the 200k mark.

As commonly said... "Your Mileage May Vary!"

[Dwight FitzSimons]

"BUT...I have to ask.. If ZDDP is such an ''engine savior'' why then isn't it in ALL Motor Oils? "

I suspect that zinc was phased out of motor oils for anti-pollution reasons.  Zinc is a metal and is what pennies are made of (with a copper plating).  We don't want to breathe fine particles of any metal.

The engine experts at SDC recommend a motor oil especially formulated for older flat-tappet engines, such as ours.  The example often quoted is Valvoline VR-1 Racing Oil, available in both mineral and synthetic.  That oil contains sufficient zinc and is the one I use in my Studebakers (synthetic).  A couple more oil companies have jumped on the bandwagon and are offering oils formulated for our older flat-tappet engines.  See pix below:

--Dwight

 

Edited Thursday at 12:01 PM by Dwight FitzSimons

[aardvark]

Good answer.Dwight.

I'm a Castrol user and won't deviate from the brand.   I think going synthetic with it's slickness pretty much eliminates the need for zinc, but then again, I'm not an expert.

Still as said, I'm running my V-8's well over 200k miles and many times to the 300k mile point.

[Gunslinger]

There are no mom and pop oil refineries...all modern motor oils come from the big boys.  As long as the oil you choose meets the specs for your particular year car you're good to go.  The oil you buy today will be different from the same brand you buy next year as car companies are always changing their recommendations and the oil companies respond.  We all have our favorites and there's nothing wrong with that.  

What may be more important...and that debatable...is using a brand from the same base oils.  With dino oils there's paraffin base and asphalt base.  They each require different levels of being refined but in the end do the same thing.  I understand Pennsylvania grade crude is the choicest oils and is generally refined into lubricants where mid-eastern oil is generally refined into fuels...just the best use of the raw materials it seems.  

Use the grade oils recommended for your application...use appropriate oil change intervals and you're good to go.

One thing I learned from car forums...if you want to start a flame war that costs many lives so to speak...start a thread that questions someone's favorite motor oil...gasoline...car wax...oil filter...tires...most anything they're passionate about in their car care.   

[wildfelr]

rqb3263/81/305

zddp was in auto oil until our lovely EPA required its removal decades ago without any consideration for engine life...... however it is not removed from diesel oil....so i just run diesel oil and through in zddp for good measure .... thats my understanding.....thats my story and im sticking to it ..... bill

[mfg]

I have an unopened can of STP up on the shelf… had it for years… has ‘Studebaker Corp.’ on it’s back…

What later became STP was used in WWll in trucks & tanks as a replacement for normal oil… and those engines ‘stood up’ with little regular oil in them…I believe STP’s excellent lubrication qualities have been proven over time.

[mfg]

I’ve never heard of roller lifters & cam for Studebaker V8 engines… yet it seems doable with minimum difficulty…..

Roller cam conversion kits have long been available for the small block Chevy… I suppose general demand would be the controlling factor here?

Edited Thursday at 04:12 PM by mfg
Added text

[DWR46]

OK, a few clarifications.

1. Catalytic Converters don't like ZDDP. That is why the EPA forced the reduction of ZDDP in today's engine oils.

2. "Slickness" is not the problem. ZDDP provides protection against the "wiping" action of the camshaft against the lifter. This is the failure point in engines with fairly high valve spring pressures and non-roller lifter valvetrains, if the engine does not have adequate levels of ZDDP in the oil. Many older engines were not performance designs and used low valve spring pressures and as such, even today, will not reflect valve train problems using lesser amounts of ZDDP in the engine oil.

3.  While synthetic oils have definite advantages, they are "slicker" and as a result will find ways to leak in older technology engines. Individuals may have Studebaker engines that do not leak with synthetic oils and that is good, but engines not designed for synthetic oils, will, as a result of the design, have a greater tendency to leak oil when the are filled with synthetic oils.

[mfg]

I have trouble understanding the difference between “slickness” and the issue of  “wiping action”…

In other words, if a surface is slick, shouldn’t that resolve the wiping action friction situation?

[DWR46]

MFG: Let me try again. The "wiping" action as the turning camshaft lobe moves across the face of the lifter tends to remove normal lubricants. Once the lubricant is removed or "wiped' away, you have a metal-to-metal interface and both the camshaft lobe and the lifter will be quickly destroyed. ZDDP when added to motor oil resists the tendency of the "wiping" action to remove the lubricant, thus preserving lubricant in this interface area and protecting both the camshaft lobe and the lifter itself.

The action of ZDDP is similar to the use of Sulphur in GL5 gear oil. Hypoid rear axle gears, as they mesh, also wipe the lubricant off the metal surfaces. The addition of Sulphur and other additives protects the gear teeth surfaces from being eroded by the "wiping' action of hypoid gears meshing together. Actually the additives embed themselves into the metal of the teeth and then get slowly wiped away (not in any measurable amounts) and sacrificed to protect the teeth. 

[mfg]

31 minutes ago, DWR46 said:

MFG: Let me try again. The "wiping" action as the turning camshaft lobe moves across the face of the lifter tends to remove normal lubricants. Once the lubricant is removed or "wiped' away, you have a metal-to-metal interface and both the camshaft lobe and the lifter will be quickly destroyed. ZDDP when added to motor oil resists the tendency of the "wiping" action to remove the lubricant, thus preserving lubricant in this interface area and protecting both the camshaft lobe and the lifter itself.

The action of ZDDP is similar to the use of Sulphur in GL5 gear oil. Hypoid rear axle gears, as they mesh, also wipe the lubricant off the metal surfaces. The addition of Sulphur and other additives protects the gear teeth surfaces from being eroded by the "wiping' action of hypoid gears meshing together. Actually the additives embed themselves into the metal of the teeth and then get slowly wiped away (not in any measurable amounts) and sacrificed to protect the teeth. 

Thank you.. that’s quite clear.

[Nelson]

I think zink additive in oil is what solved the cam problem for Studebaker’s new V8 in 1951. 
In small aircraft engines they do not allow oil with a zink additive. I’m not sure why but I heard it accumulates on the exhaust valve and causes it to stick. However, since they outlawed zink in the oil the flat tappet cams in the Lycoming engnes and others have a problem with cam lobes wearing out. 

[aardvark]

as in other Oil discussions on other forums, there is no single answer or general agreement. Everyone is an expert and in reality NONE are Chemical Scientists.

Thus all I have ever had to go on is personal experiences. After owning some 65 vehicles, I've NEVER had an engine failure due to Oil. Add to that I run vehicles until the bodies fall off for rust or other failure like head gaskets and warped parts or tranny failures. I run em to death and over the 200k mile mark... Many to 300k. One went over 400k..

So add or chemically modify as You see fit, but I'll trust in a good oil company ((in my case Castrol )) and their Scientists testing their products for longevity/  I won't mess with their chemistry.

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[Mark63Avanti]

I think DWR46 hit it on the head. Modern oil is formulated for modern cars. If you're running a flat tappet engine there probably should be some zinc in the oil, whether it comes in the oil or you add it. Adding treatments to your oil changes the chemistry. I'm not putting many miles on my Stude so I change the oil once a season.

For what it's worth, I've watched the Youtube videos by The Motor Oil Geek. I found them interesting and informative regarding the oil stock and the additives in the formulations. In some cases additional oil additives can negate the effect of the additives the oil company puts in.

When I bought my Avanti, the seller had converted it to roller rockers and wrote an article about it in the 1992 winter/spring issue of AOAI magazine. 

As far as swipes at governmental regulations, I sure wish they'd stop. How many people are still upset they took the lead out of gasoline? Maybe there's a reason kids are smarter today, just saying.

[mfg]

1 hour ago, Mark63Avanti said:

I think DWR46 hit it on the head. Modern oil is formulated for modern cars. If you're running a flat tappet engine there probably should be some zinc in the oil, whether it comes in the oil or you add it. Adding treatments to your oil changes the chemistry. I'm not putting many miles on my Stude so I change the oil once a season.

For what it's worth, I've watched the Youtube videos by The Motor Oil Geek. I found them interesting and informative regarding the oil stock and the additives in the formulations. In some cases additional oil additives can negate the effect of the additives the oil company puts in.

When I bought my Avanti, the seller had converted it to roller rockers and wrote an article about it in the 1992 winter/spring issue of AOAI magazine. 

As far as swipes at governmental regulations, I sure wish they'd stop. How many people are still upset they took the lead out of gasoline? Maybe there's a reason kids are smarter today, just saying.

Roller rockers?….In place of the rocker shaft?

[brad]

Sure, roller cam too. And don't use 50 wt oil! With modern thin low tension rings, it will rev to the moon, and make more horsepower than you ever imagined!

[aardvark]

Mark63Avanti

Yer spot on about not messing with the Oil Co's chemistry.

...........................

Depending on what kind of vehicle You us as a Daily, todays engines are very particular about viscosity.

I was told to never up the viscosity in my Ford 5.4 engine since the galleries couldn't handle the increase w/o ruining the engine. They spec 5w-20w max. So at 300k miles  I guess they're right. No smoke and the engine runs like new.

Fpllow Mfg'r's Spec's and You should be fine.

Edited 10 hours ago by aardvark