Opinions on this discussion? please

[Mazatrol]

I wondered if you gentlemen could give your opinions on this thread from Corvette forum.
http://forums.corvetteforum.com/showthread.php?t=1286330&forum_id=3

As you will see it starts off discussing cam failures and if they are indeed related to oil types. It then turns into a discussion about whether the newer oils have the "correct" additives for our older 60s and 70s era Chevy engines. Many (including myself) are just looking for the best we can get to protect a 30 year old numbers matching engine.
Although not involved in that thread I have been following closely, and found it to be more confusing than helpful.
I just wanted to hear some opinions from you fellows who discuss these things on a regular basis.
Thank you

 

[AndyH]

While I've never used it, Specialty Formulations SX-UP product gets mentioned here frequently when folks are considering additizing (is that a word?) a modern SL/SM oil for use in an older engine.

quote:

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SX-UP is a select blend of premium anti-wear (AW), extreme pressure (EP), anti-oxidant, and anti-corrosion additives in a fully synthetic carrier oil. It is designed specifically to boost the additive levels of modern SL/SM rated motor oils to meet the needs of older engine designs that require a more robust anti-wear package. SX-UP is compatible with old and new engine seals and is fully miscible in conventional or synthetic motor oils.

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More info here:
http://specialtyformulations.com/products.htm

 

[Drew99GT]

Zinc levels are not really lower from the SL days. Do a search for Castrol or Pennzoil or any brand oil in the used oil analysis section. Go to the last page of the results and look at the levels of zinc and phosphorous. The dates for those results are around 2002. Numbers look the same as these new "weak" SM oils, don't they???

In an old engine with a flat tappet high lift cam, DUH, energy conserving passenger car oil will likely equal

But a modern engine with a stock valvetrain (of which many use rollers). Fear not!!!

 

[Mr Nice]

If you want an excellent/low cost oil for your oil Vette, just use a HDEO like Rotella T, Delo 400, Delvac 1300...etc, etc.

 

[Mazatrol]

Good stuff so far gentlemen...thank you.
Drew, I did as you suggested (searching old OUA's) and things do appear to have changed little.
I've been running Valvoline 10W30 and Wix filter in my 74, but have never had a UOA done on it. The fact is..I never new they existed until I began visiting here. This car is driven very little. I change the oil once per year. The mileage between changes averages about 1500 miles. This is a rolling restoration btw.
The engine had a "freshen up" rebuild back to stock at 57K actual miles. It currently has 62K.
After viewing this UOA thread I'm concerned about the lack of moly in the oil I'm now using.
http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000328
On my next change I'm thinking of using Valvoline Maxlife 10W30. It says on the jug....for engines over 75K miles. On the back....exceeds API service SM/SL. This is a dino oil I believe.
Another oil readily available that looks good Is Shell Rotella 15W40.
Any thoughts?.....
Thank you

 

[427Z06]

A little knowledge is sometimes dangerous, IF IT'S INCOMPLETE KNOWLEDGE. User 'mountainmotor' basis his theory on the differences between the Sequence IIIF and Sequence IIIG camshaft-plus-lifter wear limits. What he isn't aware of is the fact that the valvetrain components in the specified test engines are different! Note also that the IIIG test is run 25% longer.

The concern here is with the anti-wear additive commonly called ZDTP(zinc di-thiophosphate). The thing to remember about ZDTP is that more doesn't give you better protection, it gives you longer protection if the rate of metal to metal contact is abnormally high since it is used up as it performs it's duty. (Note too that high zinc content can lead to deposit formation and plug fouling).

So an engine with aggressive profile flat-tappet camshaft with stout valvesprings are highly dependent on ZDTP (zinc) levels because they deplete the ZDTP at a much greater rate. Folks putting in a SM/GF-4 ZDTP level 5w30 synthetic in such an engine are in for a big surprise if they try to run extended oil change intervals (OCIs).

Now keep in mind that there have been limits on ZDTP since the days of API SH (1994) when a 0.12% limit was imposed. Prior to that, in the days of API SG (1989) many manufacturers already had put a 0.10% limit on phosphorus. So, “low” phosphorus has been with us for quite some time.

The API SM phosphorus limit (0.06-0.08%) only applies to 0W-20, 0W-30, 5W-20, 5w30 and 10w30 oils (so called “ILSAC” grades). API SL limits are 0.1%, but many blenders already began incorporating combinations of new additives or adding additional anti-wear and anti-oxidant to make up for this.

So given the above, I believe a majority of the problems mentioned in that thread are due to 1)improper break-in procedure 2)inferior components 3)people trying to run extended OCIs with SM/GF-4 ILSAC grade oils.

Using an HDEO will help extend the OCI some, but it too will have a limit on the length you can run it in one of these engines. One cost effective solution is to run a HDEO 10w30 if the engine is new and tight and change often. Older and looser engines may work well with the HDEO 15w40. Regular passenger car oils (PCMO) of the SL variety will work too, but you need to keep to short OCIs.

P.S. Someone might want to inform mountainmotor of his false premise.

 

[Hirev]

Camshafts and lifters were Lucky if they made it to a 100,000 miles in older stock SBC and BBC from my experience. Especially those made after 1967. It fact it was not unusual to have to put a new cam, lifters, timing chain, and cam gears in at 80,000 - 100,000 miles on the Chevy motors.

Those flame harden iron cams were not the best material for the job. Throw in heaver valve spring pressure and more lift combined with more modern fast opening lobe ramps and you do have recipe for short cam life. I have flattened my fair share of older SBC and BBC cams lobes.

I highly recommend going to a solid lifter cam using ....."good" aftermarket solid lifters with a .024 EDM hole in the middle of the lifter face, such as sold by a few aftermarket cam companys now a days. AND not running "state of the art" aggressive cam lobe ramps on a street driven motor if you want them to last for awhile.

Sometime around late 1967 the bean counters in all their wisdom at Chevy eliminated an oil slot in the parting line on the big end of the connection rod. The purpose of this oil slot as designed for the 1955 SBC was to lube the cam lobes on Chevy motors go figure. The bean counters felt it was an unnecessary extra step in machining the connection rod.

As for oil on flat tappet cams used in SBC and BBC, stick to a XXw 40 wt. Especially if you have increased valve spring pressure. The idea here is to increase oil film thickness. Avoid fuel dilution as much as possible don't run overly rich jetting.

 

[Mazatrol]

"A little knowledge is sometimes dangerous, IF IT'S INCOMPLETE KNOWLEDGE"

Ecxactly the reason I was wanting to run this past you guys. There are some very sharp people on the corvette forum, but part of the confusion in that thread (I think) is that some are performance guys who have different needs in an oil that the purists like myself.

The engine in my car is exactly like it was 32 years ago, however the Penzoil, Valvoline, Castrol, etc. that were put in this engine in those days is probably quite different now than what it was then......for emissions reasons? Correct?

Should I assume that these modern oils are good enough to take care of my needs?...or should I be searching for something that's closer to the formulation of the "older" oils?
Any thoughts on the Valvoline Maxlife or Shell Rotella? Looking through the VOA's the Maxlife SM seemed to have a better additive pack than the straight Valvoline I'm currently using.
Thanks again for all the replies....

 

[427Z06]

quote:

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Originally posted by Hirev:
As for oil on flat tappet cams used in SBC and BBC, stick to a XXw 40 wt. Especially if you have increased valve spring pressure. The idea here is to increase oil film thickness.

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Valvetrains are primarily in the boundary, mixed and elastohydrodynamic lubrication region. More viscous oil are likely of little help.