65OldsDelta88SuperRocket

I'm already putting 91 octane, the highest you can put in a car in California, but what is the best oil + grade of oil I can put in my 1965 Oldsmobile Delta 88 Holiday with the 425 Super Rocket 7.0L motor?
I read in the orginal booklet to use the higher grade of gas because it's a higher performance motor.

I currently have 116,000 miles and it runs great.

Thank you,
Olds Lover

MDchanic

Unless your timing is retarded, I would NOT use 91 octane in that motor.
It needs 93 or 94 minimum. Running it on 91 at stock timing you'll shatter the pistons sooner or later.

In terms of oil, check the manual and use the grade specified for your weather conditions, probably 10w40 in SoCal, 10w50 if the engine's sloppy.
Try to find an "Off Road" oil with extra zinc (ZDDP), as the zinc is good for the cam and lifters.
Others can fight over exactly which brand of oil is the absolute best, but that's my 2¢.

- Eric

65OldsDelta88SuperRocket

Thanks for the tips Eric!

The thing about where I live in California, 91 is the absolute best I can do!!

Unless I bought octane boosters, which at the rate my car burns gas, is ridiculous.

So you dont have a zinc branded oil in mind?

Thanks!

L69

For a zinc branded oil I have used Rotella their diesel oil is still supposed to have more zinc per million (ppm) than most passenger or gas oils. They have removed some over the past few years but def more than a traditional bottle of say Peak or Valvoline. I also know that they now sell a 10W30 version which is nice because for years I was only able to purchase the 15w40.
As for Gas I would run the highest octane which in California apparently is 91 and add a good lead substiture (NO Gunk Brand) to your fuel. (I use Red Line 60202 Lead Substitute http://www.amazon.com/Red-Line-60202...xgy_auto_img_c ) If you heads are stock they dont have hardened seat and lead will act as extra lubrication, also it is a natural octane booster and will prevent pinging just dont expect miracles, but well worth the money. The lead sub above has worked well for me for many years including many original 66 442's and F85's with original un rebuilt motors. Good luck

Sal

MDchanic

If 91 is the best octane you can get, I would strongly recommend paying very close attention to your engine, and if you get any pinging at all, retard the timing one degree at a time until you hear none.
Chronic, low-level detonation can be very bad for an engine.

As far as oil, I agree with Sal that Rotella is a good idea - it's easily available and not overpriced, and should have enough zinc for an already-broken-in engine. There are other types that have more, but I will not get into the hair-splitting discussion of precisely which one is "best."

As far as lead, I will not get into an argument with Sal, but I will say that it has been shown (and this discussion is searchable somewhere within the CO forum) that in ordinary use, your valve seats should be fine without lead.
If you tow, or spend a lot of time driving up mountains, or race, it's a different story.
A lead additive won't hurt, but I would say that it is not strictly necessary either if you just mostly drive your car like a normal person.

- Eric

Run to Rund

Either Delo 400 or Rotella 15-40 CI4+ spec, that does not meet CJ spec. This older formulation is carried by most distributors in 5 gallon and 55 gallon sizes.