changes in oil formulations and classic cars

[Andrew Schank]

Here is good article about this subject.

http://www.lnengineering.com/oil.html

I can't find that article I located that I cut and pasted here yesterday. I have a feeling the person was talking about the lighter weight Castrol oils, and not the 20/50.

[Peter]

here's Castrol's reply to my question about Zinc in GTX20W50, and whether I should switch:

"Thank you for contacting Castrol,

Castrol is aware of articles in enthusiast magazines and web-sites, as well
as after-market parts manufacturer discussions concerning GF-4 engine oils
and cam-shaft durability issues in older performance vehicles. Some
consumers suspect the lower level of ZDDP in GF-4 oils may be causing these
failures. Castrol is currently investigating this issue.

For those consumers that wish not to use a GF-4 oil in these vehicles,
Castrol does offer the following products that contain Zinc at a level that
is typical of the Zinc level found in oils (API SG) marketed during the
"muscle car" era of time:


The following Castrol products have Zinc levels that are typical of API SG
oil:

1. Castrol Syntec 20W-50 (*NEWLY FORMULATED classic oil formula - see link
to website below for information on our new 20W-50 product)
2. Castrol SYNTEC 5W-40
3. Castrol Grand Prix 4T 10W-40 (product has been replaced by Castrol
Motorcycle 4T 10W-40)
4. Castrol Grand Prix 4T 20W-50 (product has been replaced by Castrol
Motorcycle 4T 20W-50)
5. Castrol GO! ATV 10W-40
6. Castrol GO! ATV 20W-50
7. Castrol TWS Motorsport 10W-60 (full synthetic, available @ BMW
dealerships)
8. BMW Long Life 5W-30 (full synthetic, available @ BMW dealerships)
9. Castrol GO! 10W-40 Motorcycle Oil
10. Castrol GO! 20W-50 Motorcycle Oil

If installing a new performance cam in an older performance vehicle, it is
important to:
* follow the installation recommendations provided by the cam
manufacturer
* use the recommended cam break-in lube
* prime the engine oil circuits
* use the recommended engine oil
. confirm valvetrain geometries prior to starting the engine with the
new cam

*
http://www.castrol.com/castrol/gener...tentId=7032644

Castrol Consumer Relations."

So this would mean I have to switch to synthetic, right?

[Andrew Schank]

good job! Thanks for getting the latest info directly from the source-that is what I did with Shell Rotella.

From the response you got, I'd say it was safe to say the regular 20W50 old stand by Castrol probably isn't the best choice anymore.

Synthetics are fine if your car doesn't already leak and you don't mind the extra $.

[lowmileage]

I bet the'll be quite the hose job done with prices for this "new" old 20w-50. Syntex isn't even a "pure/real/actual" syn either. It's IIRC a Group 3 or a more "purified" (for lack of a better work) dino oil.

[lowmileage]

Quote:

Originally Posted by Andrew Schank Synthetics are fine if your car doesn't already leak ....

[Peter]

Quote:

Originally Posted by lowmileage they also are fine for a car that doesn't already leak that you want to leak or for a car that leaks that you want to leak more IMO.

[lowmileage]

Quote:

Originally Posted by Peter My Duetto leaks a little, the GTV leaks A LOT....I'm just too damn scared to put synthetic in either of them

[Andrew Schank]

try the 15W40 Shell Rotella I started this post about. Its not expensive, (10.99 a gallon at Kragen, a bit cheaper at Walmart if you are not boycotting Walmart) its readily available, its not synthetic. It works for 18 Wheeler trucks that put 1,000,000 miles on their engines! Many bike owners have been using it for years, and their high revving engines are harder on oil than the Alfa engines. Lastly, it is one oil that always seems to come up as a recommendation when you read articles about this Zinc/phosphorous reduction issue, and it still has the detergent package, unlike the racing oils.

I haven't noticed any increase in oil temp, reduction in oil pressure, or increased leaking compared to the 20 50 formulas I had been using. In fact, my Fiat 500 seems to start better in the morning.

[lowmileage]

Quote:

Originally Posted by Andrew Schank Many bike owners have been using it for years, and their high revving engines.....

[Peter]

Quote:

Originally Posted by Andrew Schank I haven't noticed any increase in oil temp, reduction in oil pressure, or increased leaking compared to the 20 50 formulas I had been using. In fact, my Fiat 500 seems to start better in the morning.

[Andrew Schank]

what oil temp does your car hit under hard driving on a hot day?(assuming you have a working oil temp gauge)

[alfazagato]

This is all quite amazing. I have used cheap and cheerful Comma 20/50 for the last 20 years in my Alfas, changed annually with the filter...and to date no problems. My gut feeling is that the oil is broadly similar to the oils of the 50s and 60s and if frequently changed seems to provide good pressure and, as far as I can tell, no real wear.
I am alarmed though at Castrol's comment about using 'the recommended cam break-in lube'. I have never done this in 40 year playing with cars. Is it strictly necessary?

[Peter]

nah, just water temp gauges.....oil pressure does drop significantly when the engine is hot, but I think no more on hot days, and it is considered to be normal

[Subtle]

It has been a long time since I wondered about additives to motor oil.

Did not know about zinc, however at one time molydenum disulfide(MoS2) was considered as a good addition as its crystaline structure formed flat slippery plates that stuck to metal surfaces.

Any comments on this one?

[wolfbobpalm]

As someone who has used Castrol 20w-50 for the past 30 years in my '62 Giulia spider, I have been following this thread with interest.

I did some Google research and found that on the Castrol UK website they have a listing under classic engine oils for a XL 20w-50 which they claim has all the additives necessary for pre 80s eingines.

I tried to contact Castrol UK to find out if it is available in the states but so far have not heard back.


1962 Giulia spider