I let a friend on mine, who happens to me a mechanic talk with into putting some synthetic Mobil 10-30w oil in my 455. Boy was that a mistake.The engine began to smoke as soon as I stated it.I let the engine run about 5 minutes thinking that it would clear up,but it didn't. I am sure that oil is too thin. I had regular Penzoil 3ow in there and there was no smoke.I know when I get home tonight that I will be draining that oil out. My question is if I go with 40w oil do you think that is too heavy? I am in Texas so it is very hot down here.

 

Is the smoke out the exhaust or somewhere on the engine? You should be able to fill it w/ 3 in 1 oil & not see smoke, sure wouldn't run it long though! I just retired my 10 year old 350 a few weeks ago that has been run on Amsoil originally, then for the last few years Mobil 1 5w-30. Never smoked, only used oil when I had unbaffled valve covers & it was getting sucked into the PCV line, engine partly disassembled & the best description I can come up w/ is "sterile" - no gunk, dirt, glitter, nothing. Looks like an engine on the stand being built - it's that clean. Changed once a year around Thanksgiving(3500-5000 miles)

Ran mid 13's w/ a 20 mph headwind & some wicked gusting @ track rental a few Fridays ago, motor pulled the next week. Had to pull parts getting swapped into new engine that will hopefully be on the dyno next week.

Run the same oil (5w-30 M1)in the other 350, no smoke, only on the road since last year so no reason to look inside.

I'm in CT so it doesn't get nearly as hot here & does get much colder so my needs are less demanding than yours. If you change the oil & problem goes away, Maybe it was an aversion your engine has. Drain the oil into a clean container & give it to a friend or use it in another vehicle - I would. I'm thinkin go back to what you know worked or maybe try a 10w40 or 20w50, synthetic or dyno - your preference. I know I wouldn't want to start a car on a 45 degree spring morning w/ straight 30 or 40 weight in it!

Still seems to be kinda drastic difference for a simple oil change - check other possibilities too.

 

I run 15/40 Rottella Diesel oil in mine. I get a great deal from my company on the oil. My 425 likes it.

I run this oil by recommendation of many people on this site. My machinist thinks I'm nuts.

 

Rottella T 15w40 for me as well. I've run it in my sbo 350 for about 8 years with no issues, and that's what will be going in my 455 when I get that finished up in a couple months.

 

Either go back with the 30W, or use 20W-50 (I used this in my old Ford for a LONG time), or try the 15W-40 diesel oil (I have now switched to this). The diesel oil has higher levels of beneficial ZDDP and detergents, as compared with modern car oil.
Even in our mild winters, the 15W-40 should be fine.

I live in this hot state too, and right now, it would be difficult to use too thick of a motor oil... Forcast for dallas is 100+ for the next whole week, so it is now too hot for me to even go out and do an oil change! It might get put off until fall...

 

The smoke came out of the exhaust. There was no smoke before I changed it. So I know it has to be the oil. I think I will go back with the 30w oil that I previously had in it.

 

Rob I like your idea. I will try the diesel oil and see what happens.

 

I was using Rotella 15W40 in all 3 cars but the zinc content changed so my mechanic has switched to Brad Penn I believe just had my 1st $79.95 oil change (and the fact that it had only been 1000 miles since my last one really pissed me off - he is the only one who does my oil changes, and he writes the sticker [always with the current date & miles, not next due date] but he thought I was 1k mikes past due.

Hello? Telephone? email?

Jesus H Christ

But I digress. Sorry for the rant.

 

Mobil 1 15-50 has high amounts of the correct additives for a flat tappet.
An engine burning synthetic oil, points to a malfunction, such as an intake gasket sucking oil from the valley, valve guide oil leakdown, or a bad piston ring seal.

 

Only oils I know that are good for flat tappets are Amsoil and Royal Purple in the 10w-40. Racing oils (ie VR-1), do not have the proper detergent levels for street driven cars but are manufactured for entirely different applications. Diesel oils were never recommended by GM as the oil of choice for your car, but were turned to b/c as Rob said, they had more zinc and phosphorous in them once the oil companies lowered ZDDP levels. This however has changed due to the new API rating system, so beware before you buy. The Amsoil and Royal Purple 10w-40 actually have the amounts of detergents, zinc, and phosphorus contained in them necessary for your flat tappet cam. You can request the documentation if you wish to see for yourself. That it is why I can only recommend those two.

 

w30 and 10w30 are the same viscosity at operating temps. w30 will allow more buildup deposits inside the engine than 10w30. i don't know why they even make strait weights any more. there is no need for them in my opinion.

 

If you were originally using the exact same weight oil,but non-synthetic before,& when you switched to synthetic,it smoked,it is more likely what J-Chicago said above.The synthetics are slippery,& they can find or detect some things that the conventionals don't always get.The only thing I try to do is stay with the same brand & weight of oil that the engine has always had.I don't try to put synthetics in an older,higher-mile engine that never had it before,as it usually leads to some new leaks & quirks that you didn't have before.
If you have an older engine,or maybe an original,but still runs,& you think it's gunked-up over the years,you can add a quart of transmission fluid to the oil mixture,& run it about 100 miles or so.The trans fluid has a cleaning agent,& you will get some junk out of there,if there is some.I had a 70 post coupe,with the original 350 in it,with 180,000 miles on it,when I sold it.I had done that to that engine at about 100,000. It is still running today at over 200,000 miles,with only a timing chain swap.

 

I've lost a couple cam shafts due to the low zinc oils. I suppose I couldn't prove it and there are alot of variables but it seems the high lift, heavy springed cams are much more vulnerable. Please read 71 Cutlass' post again. The cams made it 1000 miles before starting to go so I don't think it would be a bad break in. IMHO You guys using the lowered zinc oils are asking for trouble.

 

I called Mobil on this when I first bought my car, and they told me "They feel there is enough ZDDP left in thier 10-40 for the older flat tappet cars."

 

This part burns away any warm fuzzy feelings for sure.
If they can provde a lab test report indicating proper ZDDP, then I would feel more confident. I no longer trust the sole words of sales reps...

 

Actually the Oldsmobile service manuals said these oils were suitable for use in Oldsmobile engines but not required in normal driving due to additional cost. Their definition of normal driving was car was run long enough at constant speed for oil and metal temps to equalize and stabilize.


Per government/EPA mandate.


Those oils are suitable for our engines and probably a good choice in a newly built engine, but I am not about to put a synthetic or synthetic blend oil in any engine with more than 30-40k miles on it. That's asking for trouble due to synthetics' tendency to uncover leaks and open up clearances from their detergent action.

Rotella 15w40 has worked well for me since the mid 1980s. I'll continue to take my chances with it until such time as I rebuild.

 

Has anyone had any experience with oils that claim to be made specifically for classics? http://www.castrol.com/castrol/gener...tentId=7032644

 

Your post proves everything I posted. "Suitable" is not the same as recommended. And as your post says at the end "I'll just take my chances" using the oil I'm using. Go right ahead.

 

i know that Joe Gibbs makes a oil that is designed for classics, i havent tried it but i used there break in oil which i found to be good. there oils i know have the right about of ZDDP and so on, they have a sheet of the specs of whats in there oil and the percentages. be ready to pay that 9 dollars a quart though.

 

I've read that they have lowered the Zinc in Rotella as well a couple years back. It seems like playing russian roulette with your cam. Why not throw in an additive with the Rotella to be sure. Remember when a cam lobe starts making a journey to the oil pan it might take some bearing material with it. My Dad lost a cam on a 454 Corvette while he was out of town and by the time he got home he had more than a cam to repair. I know I'm laying it on a little heavy but I hate to see anyone get bogged down with some expensive repairs.

 

10W-40 is what Oldsmobile ran back in the day and at the dealership we still used 10-40 in the older V-8's 1976 down. I'm using Valvoline VR-1 oil it still has a high amount of zinc in it. The only down fall with the VR-1 is it has a lower level of detergent so I change it at 2,000 miles.

 

The Starburst Oil Myth -- The latest myth promoted by the antique and collector car press says that new Starburst/ API SM engine oils (called Starburst for the shape of the symbol on the container) are bad for older engines because the amount of anti-wear additive in them has been reduced. The anti-wear additive being discussed is zinc dithiophosphate (ZDP).

Before debunking this myth, we need to look at the history of ZDP usage. For over 60 years, ZDP has been used as an additive in engine oils to provide wear protection and oxidation stability.

ZDP was first added to engine oil to control copper/lead bearing corrosion. Oils with a phosphorus level in the 0.03% range passed a corrosion test introduced in 1942.

In the mid-1950s, when the use of high-lift camshafts increased the potential for scuffing and wear, the phosphorus level contributed by ZDP was increased to the 0.08% range.

In addition, the industry developed a battery of oil tests (called sequences), two of which were valve-train scuffing and wear tests.

A higher level of ZDP was good for flat-tappet valve-train scuffing and wear, but it turned out that more was not better. Although break-in scuffing was reduced by using more phosphorus, longer-term wear increased when phosphorus rose above 0.14%. And, at about 0.20% phosphorus, the ZDP started attacking the grain boundaries in the iron, resulting in camshaft spalling.

By the 1970s, increased antioxidancy was needed to protect the oil in high-load engines, which otherwise could thicken to a point where the engine could no longer pump it. Because ZDP was an inexpensive and effective antioxidant, it was used to place the phosphorus level in the 0.10% range.

However, phosphorus is a poison for exhaust catalysts. So, ZDP levels have been reduced over the last 10-15 years. It's now down to a maximum of 0.08% for Starburst oils. This was supported by the introduction of modern ashless antioxidants that contain no phosphorus.

Enough history. Let's get back to the myth that Starburst oils are no good for older engines. The argument put forth is that while these oils work perfectly well in modern, gasoline engines equipped with roller camshafts, they will cause catastrophic wear in older engines equipped with flat-tappet camshafts.

The facts say otherwise.

Backward compatability was of great importance when the Starburst oil standards were developed by a group of experts from the OEMs, oil companies, and oil additive companies. In addition, multiple oil and additive companies ran no-harm tests on older engines with the new oils; and no problems were uncovered.

The new Starburst specification contains two valve-train wear tests. All Starburst oil formulations must pass these two tests.

- Sequence IVA tests for camshaft scuffing and wear using a single overhead camshaft engine with slider finger (not roller) followers.

- Sequence IIIG evaluates cam and lifter wear using a V6 engine with a flat-tappet system, similar to those used in the 1980s.

Those who hold onto the myth are ignoring the fact that the new Starburst oils contain about the same percentage of ZDP as the oils that solved the camshaft scuffing and wear issues back in the 1950s. (True, they do contain less ZDP than the oils that solved the oil thickening issues in the 1960s, but that's because they now contain high levels of ashless antioxidants not commercially available in the 1960s.)
Despite the pains taken in developing special flat-tappet camshaft wear tests that these new oils must pass and the fact that the ZDP level of these new oils is comparable to the level found necessary to protect flat-tappet camshafts in the past, there will still be those who want to believe the myth that new oils will wear out older engines.
Like other myths before it, history teaches us that it will probably take 60 or 70 years for this one to die also.

Special thanks to GM's Techlink
- Thanks to Bob Olree – GM Powertrain Fuels and Lubricants Group

 

Say what you want but I still will use a high zinc oil in my car.

 

Why do you think they used a 80's era v6 engine as a test engine and not a high perf, high lift, stiff springed 454 BBC? HMMM something about that test seems fishy.

 

by all means if you feel that's what is required and puts your mind at ease, that's what you should use!!


perhaps because there are countless more vehicles on the road with the configuration mentioned in the article than the one you offered?

one theory I read concerned replacement camshaft suppliers going off shore for the manufacture of their product. when failures began to appear it was blamed on the oil, not the poor quality of the product. plausible? could be.

anyone care to speculate how many miles are accrued each 24 hours by engines with flat tappet cams or OHCs with non roller followers? If "regular" motor oils are harmful these applications should have failed long ago.

I offered the article to present an alternate point of view from a source that wasn't trying to sell a product.

 

I hear ya,
Your points are all valid. The thing I am suspicious of is the test. I've seen some tests on Car Craft that seem fishy as well. I'm not sure if it was CC but I saw a test with some BBC heads. They compared aluminum aftermarket heads to small port BBC heads known better as peanut port heads. Of course the aluminum heads out performed the GM heads but why didn't they test a factory hi perf head? I saw them test K+N filters with hp improvements and if you read the fine print you would have noted that they had made other adjustments to the car while using the K+N filter. If GM wanted Bob Orlee to show that there were no issues with modern oil, he did it the right way. He would know the mild springed cars of the early 80's that had no real HP and would hold up well to modern oils. If they wanted Bob to find fault with the oils he would have used a very stiff springed, high lift, hi perf cam. It may be an honest valid test, and who knows it could be the bad cores from China or who knows where. All I know is I've lost several cams. And most of the time it was well past break in. I would think a soft core would fail fast, not after 1000 miles. I just installed a solid roller cam in our bbc so I wouldn't have to deal with this crap anymore. I know your not trying to sell anything, it was an interesting article.