A lot of natural phenomenon can happen to something sitting on a shelf for 70 years. 

Take my sex life as an example ...

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It's sourced from the Cuyahoga and Kanawha rivers. It's skimmed right off the surface!



"FREE SAMPLE"

Where does WALLY-WORLD source it?

Who is the refiner/packager?

Would it be like their off-shore food products?

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RE: OIL WITH ZINC:
According to fellow bloggers, for a safe practical inexpensive oil for your flat tappet cars, buy the Walmart Brand 15W 40 oil for diesel engines. This oil has all the ingredients you need to protect your cam and engine parts.
It is used religiously in my '56 312 Crown Victoria............no problems.
Tim
Mud Key, FL 33704

I was just researching this since I use VR1.  On the 540ratblog, https://540ratblog.wordpress.com many (maybe all, super long document that I don't care to read all the way through) of the oils he tested were sent out for analysis.  The VR1 has as much detergents/dispersants as any other street oil, more than some and less than others.  Mobil 1 5w30 is one that I saw that has less. Pennzoil 5w30 Ultra is one I saw that has more.  Both of these are definite street oils.
The VR1 test results, 10w30, had much higher zinc and phosphorous than Valvoline indicate that it should, https://sharena21.springcm.com/Public/Document/18452/18bdee61-0a7e-e711-9c10-ac162d889bd3/a61538b4-0cbd-e711-9c12-ac162d889bd1 so either Valvoline is providing incorrect information or testing was done incorrectly or the test sample was contaminated or something else so it is possible that the test results cannot be trusted.

On a related note, a youtube channel I watch recently did a comparison between a 70 year old can of Quaker State and modern Quaker State.  The canned oil had no significant difference in zinc and phosphorous, and no detergents.  Some caveats, it did not take into account any possible reduction in those due to extended contact with the can or chemical reactions / degradation taking place.  I'm not a chemist, so I have no idea if those are actual concerns but it's something to consider.  A lot of natural phenomenon can happen to something sitting on a shelf for 70 years.  https://youtu.be/-zHlxeu_yuM Test results start at about 10 minutes.






Lawrenceville, GA

Pshaw, we were better off when the Cuyohoga had an octane rating.

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I was once told that California is a case of liberalism gone insane. I believe it is true. No wonder people are leaving there by the thousands. If you follow this you would not be able to work as a mechanic unless you wanted dirty parts and dirty hands as a permanent feature.

Y's guys rule!
Looking for McCullouch VS57 brackets and parts. Also looking for 28 Chrysler series 72 parts. And early Hemi parts.

MoonShadow, 292 w/McCulloch, 28 Chrysler Roadster, 354 Hemi)
Manchester, New Hampshire

Carburetor engines tend to have fuel wash down upon start and warm up conditions.  Fuel dilutes, washes down the cylinder walls, and collects in the oil, which causes it to deteriorate quicker than fuel injection engines.  If you have a modern EFI installed on the Y, or a fresh build with good quality rings/cylinder clearances, then after break-in, a synthetic should work fine.  A good high capacity ignition system will help with more complete combustion process, and that helps with less fuel dilution in the oil.  Joe-JDC

JDC

Phil, I'm curious as to why not use a synthetic oil in a Y block after break in?

If I'm rebuilding it using a modern ring and hone according to manufacturers specs. Bearing material has no bearing on type of oil used, nor anything else. In fact because of friction reducers in synthetic I would think it would be the best oil to use. 
I personally use synthetic oil in my daily driver and race car, also plan to use it in my Y block when finished.
Just curious as to your opinion why not?

Dave 
Even VR1 which is being touted as the thing to use advertises friction reducers