How often do you change your oil in your first gen? by the month or mile?

How often do you change your oil in your first gen? by the month or mile?

You'll find differing methods. Some guys wait 5-6k, some do it every 3k, some do it every 4mths regardless of miles, some do it the first of every spring if they're only driving a few thousand during the warmer months.... Also depends on how you drive it.

For my own car, I'll be changing it every 2-3K miles, which is being overly conservative. But as much $$$ as I've sunk in it....I can afford to keep the oil fresh :)

You want to boil the condensate out of your motor oil (not a major problem in the desert Southwest, but it is for the rest of the country). To do this the motor must get the oil above 212° F for those who live at sea level ( a little less for those in Denver) for at least fifteen minutes. The oil must not get above 240° F as it will oxidize (why it goes from honey colored to black), so you have to have an oil cooler installed; sized to shed enough heat to keep it above boiling but below 240°F.

The more you use the car on long trips the less this effects you but if you pile on a lot of short hops to cars shows this can be a killer. So though this is a mileage issue it is how it is driven that is more important than the sum total of miles. If you do not have an engine oil cooler and an engine oil temperature gauge to monitor it then I would assume anyone outside the desert Southwest has a problem with this.

High engine speeds (above 4,600 RPM) causes the engine oil to shear (literally tears the molecules into smaller hydrocarbon chains, which effects viscosity and it s ability to lubricate effectively). Finally the ash and sulfur content of the oil controls the oils ability to buffer itself against acids which are a normal by product of combustion. As the pH drops corrosion begins to deplate the engine babbit etching the bearings (dissimilar metals in an electrolytic solution). These factors take time which is why most oil companies recommend a six month interval.

Oil is cheap (especially if you use a mineral based natural oil instead of the synthetics) compared to the high priced spread. So why would any one use the high priced spread? (Besides marketing?). Because a synthetic blend has proven to reduce friction (wear) and improve mileage. Is it worth the price knowing that you will probably change out the motor for something bigger and badder before you can rack up the 80,000 mile expected lifetime of a carbureted motor? Only you and your wallet know for sure. Let your conscious be your guide.

Larger Dave

Larger Dave I couldn't of said it better myself!

Just to add to Dave's very insightful view of the subject, I myself use Walmart branded SuperTech 10w-30 in my Nova's 327, and Supertech 20w-50 in my Camaro's 383, changing every 6 months which equates to probably every 100 miles on the Camaro and every 200 miles on the Nova. Wix 51060 Oil Filter - I don't need no stinkin synthetic!

Once a year as long as Ive not driven over 25,000 miles which I never do. Amsoil 100% Synthetic 10w-40.

I change mine twice a year, no matter how much I drive it. Normally this would equate to an oil change every thousand miles or so. I never drive more than 3,000 miles a year.

I plan on changing it once a year as I only put about 500 miles on it this summer. I used valoline racing oil as it is suposed to have more zinc in it for the flat tappit cam. I also am thinking about running GM E.O.S in it for the same reason.

No GM EOS available at the moment, its $20 on Ebay, Dealers are out of stock everywhere pretty much. You might call your local dealer and have them search the dealers in the area to see if anyone has a few pints and then go buy them!
Supposedly new formulation with new part # is coming but thats been going on for 6+ months now and the new part # still doesn't work. I actually driving my Chevy II to California at the end of this week to drop it off at my friends Paint and Body shop in Corona, going to change the fluids just before and from other posts it seems I can probably use the STP 4 cyl Oil Supplement (RED BOTTLE) as a stop gap for not having access to GM EOS.

Good post Dave, but I think you're a little low, temperature wise. Oil won't oxidize at 240 degrees. You can't even use it in the frying pan at that temperature. I think conventional oils run into trouble at twice that temperature.
As for changing mine, I just keep an eye on the dipstick. It's a looky thing. When it gets cloudy it goes.

Water, air, heat, metal, and any other contaminants help break down oil. But imho, Americans have always been scammed on the necessity to change oil more frequently than actually necessary. Viscosity doesn't degrade in most daily drivers like oil companies would have you believe. Yes, it breaks down, but not normally to a point of being unfit or unsafe. Of course, having said all that, it's a cheap preventative maintenance step and not worth pushing to the limit the way I look at it. I suppose I'll always baby the 69' more than any other cars. In my daily driver 4 cyls, I've always changed the oil every 4K-4.5K miles, not 3 as "everyone" says to, and not 5-6K like the manufacturer suggests. In daily driver 8 cyls I'd normally change it every 5-6K. I've put much more than 200K on several vehicles over the years without a single issue or engine failure. Not one.

BAMiller, I found an alternative oil additive that provides Zinc, its called OReilly Oil Treatment. Cost $1.49 !! Its a 14oz bottle (about half a quart) and says on the back it states it contains Zinc dithiophosphate. I picked up a few bottles it was so cheap, seems like a good solution since GM EOS is not available to get Zinc back into our oil.

Is the EOS primarily used for solid roller cams or will hydraulic cams benefit from the use of the Zinc as well?

Hydraulic Flat Tappet cams benefit from the Zinc to prevent wear, current engine oils lack the Zinc-D because its shown to have issues with Catalytic Converts which we don't have on our Classics. EOS is (Engine Oil Supplement) that was previously offered by GM which contains Zinc-D.

Hydraulic Flat Tappet cams benefit from the Zinc to prevent wear, current engine oils lack the Zinc-D because its shown to have issues with Catalytic Converts which we don't have on our Classics. EOS is (Engine Oil Supplement) that was previously offered by GM which contains Zinc-D.

Thanks Brian. How often do you add the Zinc, I'm assuming at every oil change?

Personally I do, I use to use GM EOS, since I can't get that any longer I went on a hunt for STP 4 cyl Engine Oil Treatment, couldn't find it but Oreilly Oil Treatment states it contains Zinc-D and so I went with that, I simply add a single 14oz along with my SuperTech 10w30 or 20w50 oil and Wix 51060 filter