Pre-war (up to 1942) changing oil in my 37 la salle

[37DREAMCADDYFROMHEAVEN]

Hello members of CLC. i have been reading some posts about engine oils
when i replace my oil do i need to use additives or are there oils ready to pour in off the shelf
my 37 la salle has the original numbers matching motor.
thank for any input you can advise me with.

[Tom Boehm]

Flat tappet engines like the Cadillac flathead need higher levels of ZDDP in the oil than is in modern mainstream motor oil. There are several brands available with higher levels of ZDDP for classic cars. Valvoline VR1, Lucas Oil Hot Rod and Classic Car, Penn Grade 1 High Performance, Hemmings Magazine sells Hemmings brand Classic Car Oil. There are probably others. I was able to find Valvoline VR1 and Penn Grade locally. The rest need to be mail ordered. There are separate ZDDP additives available you can add to modern motor oil. I have read that method is risky because modern oil has some ZDDP in it and you can add too much. I guess too much is not good either. I have used all of the above except Hemmings.

[Chopper1942]

Mobil 1 15-50 has 1320 ppm zinc and 1200 ppm phosphorus. It is recommended by Mobil for use in flat tappet engines. This is the highest zinc and phosphorus levels I found published in various oil data sheets without going to a racing oil, which is usually not recommended to be used on the streets.

Valvoline VR-1 is a racing oil and it has 1400 ppm zinc and 1300 ppm phosphorus.

You can go on the various oil companies web sites and check their data sheets for the zinc & phosphorus content.

[harry s]

Do you have the factory oil filter on your car? If so this should be changed also.    Harry
PS I tried  to post a picture but not able to.

[harry s]

...I guess it did work-twice.

[Cadillac Jack 82]

Wasn't the oil filter an option?  I don't recall my 37 LaSalle having one?

[harry s]

According to the shop manual all the '37s (at least the V-8s) came with an oil filter. As far as I know from '38 up to '48 were optional and mostly dealer installed. The '37 filters were such a PITA to change a lot got tossed and by passed.    Harry

[LaSalle5019]

No additives! Use off the shelf oil.

You can read what I just posted in the ZDDP post. ZDDP wasn't even a thing when your car was built and there is plenty in today's oils to protect all but a serious race engine. If you want to waste money on specialty oils that's fine as they will do no harm, but please don't use additives.

[z3skybolt]

Interesting thread,

I used several of the above mentioned products over the years. Settled on Valvoline ZR-1 for a while until I read that "racing oil" was not intended for long term use between changes.  About 4 years ago I switched to AMZOIL Z-ROD 10w30.   It has zinc at 1440 ppm.  Stuck with it the last 8,000 miles.

This thread leads me wonder if it is necessary at all.  General consensus seems to be that no harm will be done at Z-ROD levels. Kind of like that daily vitamin.

Blue Skies,

Bob R.