When to use synthetic oil?

I have a 70 built 455. Just did break in about 100 miles on motor now. Wondering if I can use synthetic oil or not. Thinking about the Royal Purple HPS. Guys let me know what you all think.

 

I would use regular oil, 10/30, 10/40, use a ZDDP additive if you have a flat tappet cam.

 

What's a good brand regular oil?

 

Thread on engine oil technology (Re: synthetic oil?)

Dear Brandon and V-8 Buick engine oil connoisseurs,

There has been a lot of discussion about oil. Whenever the question comes up I point people to the thread that Jim Weise started on Oil Technology. As already mentioned here, you need to worry about ZDDP. However Jim mentions some further issues that one might not think about. Bottom line is that if you really love your new engine be prepared to spend extra for a specialty oil to insure it has a long life.

Cheers, Edouard :beer

 

I always switch to synthetic after 1000 miles.

 

Wish I had engines nice enough to warrant synthetic oil. All of mine have a zillion miles on them, so they get Wal-Mart brand regular oil.

 

:gp:
X2

 

Joe Gibbs x2

 

Every top-notch builder and racer I know say you might as well use water instead of conventional oils these days, its not the same oil as 20 years ago. After 500 mile breakin use Mobil1, always. It was developed back in the 70's for the space program for NASA, and I figure its good enough for the space shuttle its good enough for me. It stays clean forever, I never change it, I just change the filter and add a quart every 1000 miles or so. Why anyone would spend 1000's on a motor and then use cheap oil is beyond reason. And oil additives makeno sense either after breakin, why try to make better oil when you can start with the best already with Mobil 1? Just my 2 cents.

 

Lots of oil companies are addressing the issues of older cars now. Joe Gibbs, Brad Penn, Amsoil, etc. Just need to decide on favorite. Need to check the companies web sites and check on the ZDDP. The number to look for is around 1300. I use Valvoline racing because I can get it at most auto parts stores. Pick it up on sale because an oil change for me is 9 quarts :eek2:

 

Use water? There is nothing wrong with regular oil. It is what it is.

And why would anyone spend $1000s on a motor and be too cheap to change the oil rather than add a quart and change a filter. o No:

 

Not to mention the reason that engine is using a quart every 1000 miles is because the oil is so full of carbon particles that the oil has no lubricity left and the rings and cylinder walls are quickly eroding. That post was just chocked full of misinformation.

When did the space shuttle get an internal combustion engine? Do they bring along bottles of good cool low altitude air to run it??? :laugh:

And guess what folks, even some high end synthetics still don't have enough ZDDP for higher spring pressures on a flat tappet lobe. Ask my poor flat 308S cam that came out a few years back after losing two lobes despite how amazing Mobil 1 is supposed to be.

Devon

 

I gave him the benefit of the doubt that the quart every 1000 miles was because of the filter change.

 

Which is another perfect example of putting perfectly good money through a document shredder if indeed this is the case.

Devon

 

Yes the 1 qt. was for the filter change. Mobil 1 is so good there's no need to change it, as long as you use a quality filter, and it does its job by removing all the crap its supposed to. But to each his own, just stating what has worked for me over the last 30 years. And NASA developing Mobil 1 was for components that needed it, lol, probably not the engine, lol. As for losing a cam with 2 bad lobes it wasn't from Mobil 1, it was from bad break-in guaranteed.

 

Oh right - that surely explains why the cam went through break-in fine in the mid 1990's and survived just fine for years prior to the drop in ZDDP in motor oil across the board. Now do you still think it was a bad break-in? I have never lost a cam due to break-in over the last thirty years since I replaced my first.

And just an FYI, the oil filter does NOT filter carbon particles from the oil, and your wishing it would does not make it so. In case you're unaware, the biggest job of motor oil after maintaining lubricity is to collect and surround carbon particles due to combustion so their ability to abrade against metal components is reduced. When the oil becomes overly saturated with carbon, wear increases. The only thing keeping your engine going is the 1000 mile one quart change, during which you are throwing away a perfectly good oil filter about ten times more often than necessary. Highly unorthodox and not something I would recommend to anyone.

Devon

 

Ok, you win,I'm stupid. But I thought ZDDP was critical only for breakin, it promotes metal wear and hardening for the metal-to- metal surfaces and after initial breakin it wasn't needed because MORE metal wear is not needed, therefore remove it and run fully synthetic is the right move? Maybe not. And JMHO, when I change the filter,Mobil 1 looks and feels like new its that clean, something very different from other oils I have used over the years that feel and look dirty after just a couple hundred miles, and carbon shouldn't be a problem with a properly built and running engine.

 

The ZDDP is still a big deal for daily health of our old flat-tappet cams. Even when the zinc levels were high enough to handle a properly broken in cam & lifters, a new cam & lifters still needed extra help which why we relied on molybdenum based paste and other high pressure lubricants for break-in, and still have to today.

But with the flat tappet being phased out and universally replaced with roller lifters, engineers found they could tolerate much lower ZDDP levels in order to promote catalytic converter life. So now, all of us with flat tappet cams suffer, especially with high spring pressures and high valve lift which is really hard on parts. Some specialty oils are out now as have already been discussed. Even some high quality synthetics like Mobil1, with their high pressure additives can use some help in the ZDDP department for everyday use unless you find a blend being offered that is formulated with additional ZDDP for just this reason.

If your oil is not darkening significantly, you may be alright...the darkening is due to carbon absorption which synthetics handle better than conventional oils. Many change their synthetics too frequently because they're scared by the color which will progressively darken with more engine hours, it's just the way it is. So if your synthetic oil is never darkening, you're adding fresh oil much too frequently. And regardless of engine build quality, Carbon is always present and must be dealt with...it's simply a byproduct of combustion. The rings pull it off the cylinder walls and it's picked up by the oil. If you run an engine hard all the time, carbon in the oil will have to be addressed more frequently compared to a car getting a steady part throttle cruise down the highway all day.

Rather than play the guessing game with oil and filter change intervals, I'd stick with what the oil manufacturer recommends, especially when giving advice to others with no idea of how their engine is intended to be used.

Devon

 

This topic came up at one of the ROA tech meetings at the Monterey event last month. For all of our 60s and 70s Buick V8s, the zinc level in the engine oil is a major factor. The minimum level which was stated by the ROA tech folks is 1000ppm, or 0.1%.

I, too, am one of the Mobil 1 users, and normally use a mix of 15W-50 and 10W-30. The 50W has a zinc level of 1300, but the 30W has only 900. Checking the material safety data sheet, there are some Mobil 1 grades which have as little as 750 or 600ppm zinc. I feel that keeping in the neighborhood of 1000 should be a general rule, even if the vehicle isn't raced or driven hard for long distances.