engine oil

[Guest roadmistress]

Hi Everyone,

Just wondering what advice I can get regarding engine oil for my 48 roadmaster.

how does everyone feel about 30w?

I have the car in Los Angeles.

Thanks!!

[Guest Straight eight]

Have driven straight eight Buicks since the 60's and have used SAE 30 weight Shell Rotella the whole time, no problems. Rotella is both a diesel and gasoline engine oil, and contains enuff zinc for protection of the lifters. I believe the current rating for Rotella straight 30 weight in 1200 ppm which should meet your engine's requirements.

Edited September 18, 2010 by Straight eight (see edit history)

[Ben Bruce aka First Born]

30wt Rotella is a good choice. That is what I use in my '50.

Ben

[Guest roadmistress]

Ok, great to know. Thanks so much for your help. Have a great weekend!

[MrEarl]

:eek: Woohooooo!!! now that is a picture for Girls on Buicks. Should get it right back on topic as from what I recall the last post there had Thriller and Roy talkin about side mirrors.

Here, let me take you there...click here > http://forums.aaca.org/f115/girls-buicks-iv-259016-14.html#post790638

and also, I don't seem to recall seeing you and the Roadmaster in the Me and My Buick forum either. Here, I'll take you there too > Me and My Buick - AACA Forums

one more thing and I'll get this back on topic

Welcome aboard and hope you'll make this a regular pit stop for questions and good fun.

Now, sorry I can't help you with the oil question... all I have are V-8's.

Edited September 18, 2010 by MrEarl (see edit history)

[Thriller]

:eek: Woohooooo!!! now that is a picture for Girls on Buicks. Should get it right back on topic as from what I recall the last post there had Thriller and Roy talkin about side mirrors.

How'd I know you'd jump on that?

Wasn't the most recent some gals in Ames on '54 Buicks? :cool:

[NTX5467]

That is ONE flashy and snazzzzzy picture!

Mr. Earl, I guess that V-8s and straight 8s can't use the same oil????

From my research, straight-weight 30 oil is outside of the current OEM recommendations for newer cars, so it never did make it past the "SL" API classification to be approved for more modern AND later model vehicles.

Just some thoughts,

NTX5467

[Guest roadmistress]

Thanks for all the help. Okay I posted my pic on girls on buicks!!

[Guest sconnors]

Great picture!! Great car!!

[MrEarl]

Mr. Earl, I guess that V-8s and straight 8s can't use the same oil????

Just some thoughts,

NTX5467

V-8 or straight 8, I guess earl is earl. enter smilie duucking tomatoes here:p

[NTX5467]

"earl is earl", or so THEY say.

I found some Rotella T5 at WalMart last night. A semi-synthetic blend in 10W-30. T6 is their normal synthetic oil in 5W-40, with normal T being 15W-40.

If straight 8s and V-8s used the "same oil", they'd better be joined at the drain plug . . . so they can share the same oil rather than having their own unique supply.

Bye, now . . .

NTX5467

[Cubelodyte]

Having just put 8 quarts of (Castrol) 30w in my Roadmaster, I've been reading up about ZDDP, and I've found some forums and other pages that seem to indicate that even Shell Rotella oils have a drastically reduced zinc content due to EPA regulations. Has anybody else heard about this?

I'm thinking it might be wise to go buy some additive before I fire the engine up...

[Guest Oldie & Goodie]

I just did my first oil change on a 51' Roadmaster using Bard Penn straight 30. High in the additives and non-detergent.

I hope this is a good sign but the engine actually seems quieter after the change. Previous owner used straight 30, don't know what brand. I ran it about 300 miles with whatever oil he had used but hopefully the additives are what is reducing the engine noise.

I read alot about oil, Brad Penn seemed like a good choice and at $6.25 a quart it didn't seem too unreasonable.

[old-tank]

Most straight weight oils and higher number multi-vis oils have adequate zinc for an engine that is broken in. I use Castrol 20w-50 in all of mine including the one in the avatar: rebuilt engine 12 years and 75,000 miles ago and it is still running strong.

Willie

[NTX5467]

I went through the www.bobistheoilguy.com website last night to check for older virgin oil sample analysis' posted by members of their forum--45 pages of such. The Mobil oil website has a chart hidden in it that has the zddp levels of all of their oils, too.

The original comments from Comp Cams was "Rotella T 15W-40 or synthetic", with regards to the cam/lifter wear concerns. Now that we're several years past that, most of the main aftermarket cam manufacturers had their own oil additives and now, I believe, their own high-zddp motor oils. Plus some other speciality oils have come online, too, targetted at the vintage vehicle hobby.

Interestingly, though, on the crate motors that GM still builds with flat tappets, their recommendation is high quality "SM" motor oil. This tends to verify my own suspiciion that the factory cams got more parkerizing than the aftermarket replacement brands did, plus the tappets are of known OEM quality, too. The bulk of these engines have also been "fire tested", meaning they've already done their initial run-in on an engine stand at the engine plant.

Even 30+ years ago, a cam manufacturer would not warranty a worn cam if THEIR lifters were not installed . . . and they could determine if the lifters which were sent in with the "bad" cam were theirs, too.

As Willie and others have mentioned, if the OEM cam is already broken-in, then the lower zddp oil would probably not be an issue.

What I found was . . . I think that earlier 2000s Rotella T 15W-40 and other similar diesel-spec oils might have had zddp up to 1450ppm (SJ and SL ratings), whereas current Rotella T is closer to 1200ppm, with the newer Rotella T5 syn-blend 10W-30 being basically at 1200ppm too. When looking at the synthetic Rotella 5W-40, it always has been close to 1200ppm, too, but ALSO a synthetic. So, basically NO change from them to now for the 5W-40 Rotella T, although Shell has illustrated that the new T6 version has much better cleaning properties.

Normal SM oils are in the 800ppm range, plus or minus. I understand it has an upper limit for the SM and Euro ratings. The lesser number is to prolong catalytic converter and other emissions controls' useable lifespan.

Royal Purple usually tested in the 1400ppm range as an "SL" oil. Other older "SL" oils didn't test that high, though, but close.

In the world of European vehicle brands, VW had some issues with their diesel engine fuel pumps wearing the cam lobe it runs on IF the correct spec oil is not used. Their recommended Castrol 5W-40 SynTec oil is "SL" rated and generally tests at 1100ppm zddp. Each Euro manufacturer generally has their own oil spec number, so it working for one brand does not guarantee it'll work for another brand of vehicle or a particular engine therein.

Many in the bobistheoilguy forum like the Brad Penn oils. You can find oil analysis results posted for it in their "Virgin Oil Analysis" listings.

There ARE some ins-'n-outs of motor oil anti-wear additive package formulations, though. Zddp is not the only anti-wear additive available, but it usually was the most cost-effective. Plus adding lots of zddp can also somewhat deactivate the detergency additive package, too! It's a big balancing act for the intended use of the particular motor oil.

After I went through the oil forum postings, I wandered into the oil filter postings. One poster had pictures of a Fram Xtended Life oil filter. NOT the normal Fram filter we've heard about . . . BUT the internal construction was identical to what I saw on an Internet video of how the Royal Purple oil filters were made! Quite interesting!

By observation, NONE of the cam lobe issues will happen immediately, but might happen over a period of thousands of miles of normal use. Unless, the lobe was already worn excessively and the fresh oil change didn't help matters.

Just some thoughts,

NTX5467