Sactownog

OIL RECOMMENDED VS WHAT YOU THINK

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Just NEVER consider using non-detergent oil in a rebuilt engine! Anything else on the shelf at the store will work fine.

 

The 230 cu in was designed before the oil companies put any ZDDP in oil!;)

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Benefits of AACA Membership.

5 minutes ago, Frank DuVal said:

Just NEVER consider using non-detergent oil in a rebuilt engine! Anything else on the shelf at the store will work fine.

 

The 230 cu in was designed before the oil companies put any ZDDP in oil!;)

 

It is to my understanding zinc was introduced in the late 1930s. 

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Invented in 1941 by Lubrizol.

 

API SB oil came out in 1930 or so, with SA being for engines up to 1930. SC is for engines built after 1951. So unless API changed the specs between 1931 and 1951 to include ZDDP, it didn't show up in requirements until SC rated oil. I cannot find API requirements for additives in SB and SC oil, though, so I can be wrong!😁

 

http://www.pqiamerica.com/apiserviceclass.htm

 

230 cu in. first in 1942 Dodge. 

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I have a 1966 Morgan with a four speed Moss gearbox.  Most people recommend using a 30 weight oil in it. Mine had 30 weight in it, but I was unhappy with its performance. It shifted more slowly than it should and had the annoying problem of popping out of gear on hills. I replaced the 30 weight with RedLine MT 90, based upon the company's recommendation.  The car now shifts more smoothly and quickly and no longer pops out of gear, even on very steep hills.

 

However, when I tried the MT 90 in my 1935 Cadillac, it made shifting awful. The synchronizers barely worked at all. I suspect the MT 90 is too light an oil for that transmission. I’m currently trying to sort out what to try next - probably Redline or Amsoil 75w140. Both are claimed safe for yellow metals.

 

Phil

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15 minutes ago, pmhowe said:

However, when I tried the MT 90 in my 1935 Cadillac, it made shifting awful. The synchronizers barely worked at all. I suspect the MT 90 is too light an oil for that transmission. I’m currently trying to sort out what to try next - probably Redline or Amsoil 75w140. Both are claimed safe for yellow metals.

I had the same experience with my 1936 Pierce.  I've had best results mixing GL-1 90 and 140 half-and-half.  That car also has a standard BW OD, and I use the same lube in the OD box, and there's migration of oil between the two boxes.  My 1948 Willys, also with a BW OD, owners manual is very explicit in its instruction to use straight mineral oil (i.e., GL-1) in the trans and OD but Extreme Pressure (EP) oil in the diff.

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That's not really how it is supposed to work. The synchronizer is a friction device, literally a brake. The issue isn't weight, its that the oil cannot be too slippery or the synchronizer will not be able to stop the gear. Hypoid gear oils are really slippery and do everything in their power to prevent the braking action. Some synchronizers are huge, and have perpendicular grooves machined in them to scrape the oil off of the cone. Those can deal with extra-slippery oil for a while. Maybe not forever. Others may be just barely working when new.

 

Heavier oil can slow gears down quicker, and help with shifting in spite of synchronizers that don't really work. It boils down to timing.

 

Grimy mentioned GL-1. That is close to straight mineral oil, and is likely to provide much better results than typical GL-4 or GL-5 gear oil from the parts store.

 

 

Edited by Bloo (see edit history)
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26 minutes ago, Bloo said:

That's not really how it is supposed to work. The synchronizer is a friction device, literally a brake. The issue isn't weight, its that the oil cannot be too slippery or the synchronizer will not be able to stop the gear. Hypoid gear oils are really slippery and do everything in their power to prevent the braking action. Some synchronizers are huge, and have perpendicular grooves machined in them to scrape the oil off of the cone. Those can deal with extra-slippery oil for a while. Maybe not forever. Others may be just barely working when new.

 

Heavier oil can slow gears down quicker, and help with shifting in spite of synchronizers that don't really work. It boils down to timing.

 

Grimy mentioned GL-1. That is close to straight mineral oil, and is likely to provide much better results than typical GL-4 or GL-5 gear oil from the parts store.

 

 

 

It is a brake and the friction material seen inside the cup for sure. Great post and how oils affect operation. 

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