Flint/Tonawanda/St. Louis "breakin oil"

[Duke W.]

We've had a zillion threads on oil and engine breakin, but the subject of this one is what did GM use for "breakin oil" back in the vintage era.

My '63 AIM shows lubrication symbol "3a" on Sheet A3.00 Sect. 6 and Sect. 14 lists "3a" as "3845679 engine oil" 1375 gal. per 1000 jobs, which is 5.5 quarts per job.

The sheet change record dated 1-23-63 indicates the previous engine oil number was 3814873 and the prior quantity "was 1250 gal [per 1000 jobs] base & L-75", so the quantity change must have been recognition that the actual quantity per job varied with the mix of engine options because L-76 and L-84 had a quart more capacity than base and L-75.

So if St. Louis added engine oil, then Flint must have drained the oil out of engines after the hot fire test and prior to shipment. Did they use the same oil for the next hot fire test?

Back then I always understood that the plants used some sort of "breakin oil" and thought is was basically just common SAE 20-20W API MS oil of the sixties.

Was this oil actually the same as any store bought 20-20W MS oil of the era?

Was 3814873/3845679 a special blend that incorporated more anti-wear additive?

The single number indicates the same oil was used year round. Is this the case? What about cars shipped to the upper Midwest in winter?

Duke

[Marc R.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

Duke, I've read your many posts and you're obviously the oil expert. I'm sure many of the old timers know your background, but I'd like to know what you did in your previous life.

[Duke W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

I'm my previous life from from the mid-nineteenth to early twentieth century I was a fireman on the Pennsylvania Railroad.

In my current life I was promoted to "engineer", but not on the railroad - auto and aerospace engineering, and the latter part of my career was spent in the computer industry - marketing CAE tools to the aerospace engineering community.

I started my current life career with a brief stint as a production engineer at Pontiac, then went off to grad school for a MSME at the U. of Wisconsin Engine Research Center.

In my next life I want to be Chairman of the Federal Reserve Board.

Duke

[John H.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

So if St. Louis added engine oil, then Flint must have drained the oil out of engines after the hot fire test and prior to shipment. Did they use the same oil for the next hot fire test?

Back then I always understood that the plants used some sort of "breakin oil" and thought is was basically just common SAE 20-20W API MS oil of the sixties.

Was this oil actually the same as any store bought 20-20W MS oil of the era?

Was 3814873/3845679 a special blend that incorporated more anti-wear additive?

The single number indicates the same oil was used year round. Is this the case? What about cars shipped to the upper Midwest in winter?

Duke

Duke -

The hot-test stands at the engine plants were supplied with oil from a central circulating system, with a rather elaborate filtration facility. At the conclusion of hot-test, the plug was pulled and the oil went into a drain that took it back through the filtration system, then back into the circulating supply loop. I don't know the details of how the filtered oil was monitored or "freshened".

The oil at the assembly plant was delivered in tank trucks or rail tank cars and pumped into the plant's "tank farm", and it was pumped from there to the fill point on the engine dress line. I don't know if the initial fill oil was a unique blend or not, but it didn't change from season to season, and doesn't today either.

[Marc R.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

I don't know about the Federal Reserve, but the rest sounds impressive. Thanks; one never knows without asking.

[Chuck S.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

I'm my previous life from from the mid-nineteenth to early twentieth century I was a fireman on the Pennsylvania Railroad. ...

You and Shirley Maclain...Is there something in the water out there in the "Golden State". Forget the Federal Reserve...I want to come back as an energy trader. HaHaHa...

[Duke W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

You'll go to jail, Chuck, and I'll retire as "The Chairman" with never ending accolades and write a best selling book. (Just finished Greenspan's "Age of Turbulence "- a great read!).

Case in point - last Tuesday at 0600 a dozen armed federal agents raided a neighbor two doors to the south of me with an arrest and search warrent - "identity fraud scheme". They confiscated his Porsche Turbo and several properties he owns. Crime doens't pay, and I need to get out of my crime infested 'hood.

Thanks, John, I figured you knew at least part of the story - anyone else?

Duke

[Dick W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

In another era of my life/career, I was in fleet maintenance. We had some very problematic engines that had, at best, oil consumption of 500 miles per quart. The factory service engineer? was less than helpful to say the least. I called a well know piston ring company and they sent a sales engineer down to help up. Long story short is that according to him the breakin oil, at least in the late '60's, should be of the same grade and spec as you planned to run in the engine for life. BTW, he solved our problems.

[Duke W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

How did he solve the oil consumption problem?

Duke

[Dick W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

We were replacing the short blocks with new ones from the factory. The engine life was less than 20k in this application. He told us to disassemble the engines, re-hone the cylinder walls, and install his company's moly rings. We did as he told us to and when I moved to another location with the company the lowest mileage engine in that group had over 35k on it and oil consumption was averaging about 1,200-1,500 miles per quart as I remember it.

We inherited this group of vehicles with a buy out of another company. The vehicles were grossly overloaded and under powered. We also had a few 366 cid and 427 cid Chevies. The 366's were a good 200+k engine and the 427's would last 125k to 150k. Those 427's were stout! They would almost pull with the V-12 (702 cid) GMC gas engines. And gas, with a fleet contract, was about $.24 in Texas in that era

[Duke W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

It sounds to me like the OE engines had chrome plated top rings and were not broken in properly. I don't know when Chevrolet switched to moly-faced top rings, but I think it was in the early seventies. Moly rings are fairly indifferent to breakin. It occurs very fast.

The chrome rings needed a "not too hard", but "not too easy" breakin, and if not done correctly were prone to high oil consumption. My '63 L-76 used some oil until about 10K miles because I think I broke it in "too easy".

From about 10K the oil consumption remained at about a quart every 1500-2000 until I tore it down at 115K. SHP engines with looser clearance forged pistons tended to consume more oil than the non-SHP engine with snug fit cast pistons.

Chrome rings have better abrasion resistance than moly rings, but with good OE air filtration chrome rings offer no benefits, but have the touchy breakin issue. Despite chrome rings the only measureable wear in my engine was bore taper - .003" with two at .005". I attribute this to the poor filtration quality of the OE foam filter, despite the abrasion resistant chrome rings.

Duke

[Bud K.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

I enjoy these jawin' sessiones around the pot-bellied stove.

Bud.

[Ray G.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

Hello;
'62 -63 in the Chevrolet Dealership in which I worked we had many complaints of oil consumption on 327s.
Chevrolet Area Service Managers would tell customers to keep the "break-in oil" in 4000-5000 miles and if you drained the "break-in oil" to soon the rings would not seat.

As service department employees we believed the break-in oil was used to offset the new casting acidity.

Seemed to work at the time.

Hope this helps.
Ray

[Duke W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

That may very well be. I changed the oil and filter in my SWC at about 500 miles, and I recall the dealer service people telling me I should have left it in longer when I complained about oil consumption, but the question remains: What was difference between the "break-in oil" installed at St. Louis and the commercially available "heavy duty" oil of the era (API service category MS)?

BTW, the recommended oil change interval in '63 was every 60 days (my emphasis) or 6000 miles whichever occured first, and the filter change interval was every six months or 6000 miles. This is right out of the 1963 Corvette Shop Manual.

In those early days I changed the SWC oil every three months (2-3K miles), and changed the filter every other oil change.

The MS oil of that era was the first to have a good dose of detergents/dispersants and ZDDP, but the base oil was nowhere near as good as today's oils in terms of oxidation resistance. The 6K mile interval seems reasonable for the era, but the 60 day deal seems excessive even given the lesser quality of the base stocks use to blend oil 45 years ago.

When I disassebled my engine at 115K the interior was free of any sludge - near spotless.

Duke

[Dick W.]

Re: Flint/Tonawanda/St. Louis "breakin oil"

From about 10K the oil consumption remained at about a quart every 1500-2000 until I tore it down at 115K. SHP engines with looser clearance forged pistons tended to consume more oil than the non-SHP engine with snug fit cast pistons.

Duke

Heck, some of these engines were blowing up before 10k miles. A combination of soft blocks and sorry rings. But then again an under 400 cid gas engine should not be expected to gross 80k at 55 mph either.