1954 break in oil question

[Guy M.]

Hi folks. I have 500 miles on my car since back on the road. I have Joe Gibbs break-in oil in it. The rings have seated as there is no smoke what so ever. Hoe long would you run this oil till the first oil change? My machinist said it wouldn't hurt him to see 3000 mile on it. Seems a bit high to me but I'm not sure. What do you folks think. Thanks as usual. Guy.

[Michael W.]

Re: 1954 break in oil question

According to the manufacturer, you're already overdue.

I'd read Duke's articles on what to use from now on and see what's on sale today at Wally World that fits the bill.

[Mike M.]

Re: 1954 break in oil question

i change oil on a freshly rebulit sbc or bbc when the 20 minutes at 2000 RPM ends. mike

[Chris S.]

Re: 1954 break in oil question

One of the main reasons for break in oil is ZDDP - Zinc dialkyldithiophosphate
Cam lobes and flat tappet lifters are crucial to break in during the first couple minutes of starting
The 235 has such weak spring rates it is not as a huge concern as it is with say a L88
Never the less - if you have broken in the motor - I would change the oil
Me personally I use Shell Rotella with a bottle of ZDDP.
Plus remember there is no filter on the 235's so any break in particles are floating around
You would want to drain those.

[Guy M.]

Re: 1954 break in oil question

Thanks everyone, I'm uncovering it next weekend. Its been sleeping since Thanksgiving. Chris, Ill take your advice on the oil, What viscosity do you use?

[Duke W.]

Re: 1954 break in oil question

There's no need to add supplemental ZDDP to CJ-4 oil; 15W-40 is okay for cold starts down to about 15F.

Duke

[Mark E.]

Re: 1954 break in oil question

There's no need to add supplemental ZDDP to CJ-4 oil; 15W-40 is okay for cold starts down to about 15F.

Duke

Any disadvantage of 5w-40 vs. 15w-40?

[Chris S.]

Re: 1954 break in oil question

There's no need to add supplemental ZDDP to CJ-4 oil; 15W-40 is okay for cold starts down to about 15F.

Duke

- true but a little cheap insurance doesnt hurt esp on a new motor - just my .02

[Duke W.]

Re: 1954 break in oil question

Any disadvantage of 5w-40 vs. 15w-40?

...just the price, which is about double 15W-40.

Duke

[Michael W.]

Re: 1954 break in oil question

- true but a little cheap insurance doesnt hurt esp on a new motor - just my .02

It's just as likely to do more harm than any good. Read up on excessive ZDDP levels and on non-compatible oil additives.

Modern CJ4 oils have far more ZDDP that the oils of the 1950s so straight out of the bottle is already overkill.

[Michael W.]

Re: 1954 break in oil question

Chris,

The text above mentions using API SN oils. They have nowhere near the ZDDP levels contained in CJ4 which is what is being discussed here.

BTW, If you're going to plagiarize someone's else work, at least give them credit.

https://www.amsoil.com/newsstand/classic-and-vintage/articles/reduced-zddp-and-wear-protection/

[Duke W.]

Re: 1954 break in oil question

Current C-category oils have a P limitation of 1200 ppm and most spec-out in the range of 1100-1200, which is about what S-category oils had before SL went to 1000 and SM/SN to 800. In fact, prior to the first S-category P limitation most of those oils were dual rated for both S and C-category service.

More than about 1400 ppm P over the long run can lead to some exotic corrosion mechanisms, which is why it's not a good idea to add extra ZDDP to C-category except for break-in.

For the umpteenth time I've attached the oil article. If you have not previously read it, now is a good time, and remember, I'm not trying to sell you anything... just providing the facts that should enable anyone to make the most economical purchase.

Duke